Radiographic imaging method using multiple energy exploration views

Abstract

The invention relates to a radiographic imaging method comprising at least one operating mode, in the operating mode, a front multi-energy exploration view and a side multi-energy exploration view are obtained by preliminary vertical scanning of a standing patient along a vertical scanning direction by front and side radiation sources (101, 103) and by front and side radiation detectors (102, 104), and a rear multi-energy exploration view is obtained by preliminary vertical scanning of the standing patient along a vertical scanning direction by the front and side radiation sources (101, 103) and by the front and side radiation detectors (102, 104). Such that the front and side radiation detectors (102, 104) give at least: a first front probing view corresponding to the low energy front probing view, a second front probing view corresponding to the high energy front probing view, a first side probing view corresponding to the low energy side probing view, a second side probing view corresponding to the high energy side probing view, and a third side probing view corresponding to the high energy side probing view. And a processor (20) corresponding to a high-energy side probing view, combining and processing (20) the first front probing view and the first side probing view and the second front probing view and the second side probing view in order to assess at least a patient bone thickness (22), at least a patient soft tissue thickness (22), at least a patient soft tissue thickness (22), at least a patient bone thickness (22), at least a patient bone thickness (22) and at least a patient soft tissue thickness (22). Patient-specific bone localization at different imaging locations along the vertical scanning direction (21).

Description

Technical Field

[0001] The present invention relates to the technical field of radiation imaging methods and radiation equipment for carrying out the radiation methods. Background Art

[0002] Different types of radiographic images can be done, among them:

[0003] - a radiological scan image dedicated to a general (detailed and complete) view of a patient or an organ of a patient or a part of a patient's organ, which is used for diagnosis by a practitioner,

[0004] - Radiological scan images dedicated to the distribution of bone density in a patient's body, which are used by practitioners to assess the bone density of the patient or an organ of the patient or a part of the patient's organ.

[0005] The radiological image is preferably an X-ray image.

[0006] In order to improve the accuracy of diagnosis and / or bone density assessment, in a first step, an exploratory view is taken, and then the information extracted from this exploratory view is used to adapt the imaging parameters, and a scanned image is taken, which is then used by the practitioner for diagnosis or for bone density assessment.

[0007] The exploratory views and scan images are performed by vertical scanning along the height of a standing patient, a frontal image capturing line including a frontal radiation source and a frontal radiation detector, and / or a lateral image capturing line including a lateral radiation source and a lateral radiation detector.

[0008] According to the first prior art, when a single energy exploration view is performed followed by a single energy scan image, the imaging parameters are adapted so as to allow a good quality diagnostic image to be obtained, but it does not give a good bone density assessment result, i.e., a good bone density assessment result cannot be derived from the diagnostic image. Then, if a bone density assessment is also required, not only should a new scan image with different imaging parameters be completed, but this new scan image cannot correspond precisely to the previous scan image in terms of topology, because the standing patient will move at least a little in between.

[0009] According to the second prior art, a multi-energy scan image is performed, and the imaging parameters are adapted so as to allow a good quality bone density image to be obtained, but it does not give a good diagnosis result, that is, a good diagnostic image result cannot be derived from the bone density image. Then, if a diagnosis is still required, not only should a new scan image with different imaging parameters be completed, but this new scan image cannot correspond precisely to the previous scan image in topology, because the standing patient will move at least a little in between. Summary of the invention

[0010] The object of the present invention is to at least partially alleviate the above mentioned disadvantages.

[0011] More particularly, the present invention aims to provide a scanned image which can be used for diagnosis with good results and which:

[0012] - A partial exploration view can be extracted from the scanned image and further combined into a multi-energy exploration view in order to also give a correct bone density assessment result at the expense of a simple multi-energy view and at the expense of a lower radiation dose (the exploration view is performed at about 10 times less or even less radiation dose than the scanned image). The combination of two partial exploration views will lead to an accurate assessment of bone density. Thus, a good diagnosis and a correct bone density assessment can then be derived from the scanned image and from its exploration view in a fairly simple manner in a single global operation.

[0013] - or at the same time partial images may be extracted from the scanned image and further combined in order to also give a good bone density assessment result. The combination of the two partial images will lead to an accurate assessment of the bone density. Therefore, both a good diagnosis and a good bone density assessment can then be derived from the same scanned image. Furthermore, since both a diagnosis and a good bone density assessment are derived from the same scanned image, there will be an exact topological correspondence between the diagnosis and the good bone density assessment, since a standing patient is in exactly the same position for both.

[0014] Therefore, to be suitable for both diagnosis and bone density assessment with good quality, radiological methods use:

[0015] - First, a multi-energy exploration view. In the prior art, this exploration view is only a single energy view.

[0016] - Secondly, the extracted information from this multi-energy exploration view, which is then used to make an improved scan image, whether a single-energy or multi-energy scan image, which in the prior art is only single-energy.

[0017] The multi-energy exploration view will give even better results if it is performed before the multi-energy scan image instead of before the single-energy scan image.

[0018] The multi-energy exploration view may be a front exploration view or a side exploration view, or may include both the front exploration view and the side exploration view.

[0019] A first object of the present invention relates to a frontal single-energy or multi-energy scanning image performed after a frontal multi-energy exploration view.

[0020] This first object is achieved using a radiographic method comprising:

[0021] Two radiation sources, one front radiation source and one side radiation source, whose imaging directions are orthogonal to each other, the radiation sources slide vertically so as to perform vertical scanning on a standing patient along a vertical scanning direction,

[0022] two radiation detectors respectively associated with the two radiation sources, a front radiation detector and a side radiation detector, the radiation detectors vertically sliding so as to vertically scan a standing patient along the vertical scanning direction, at least the front radiation detector being a multi-energy counting detector,

[0023] The radiation method comprises at least one operating mode in which:

[0024] A frontal multi-energy exploration view is obtained by performing a preliminary vertical scan on a standing patient by the frontal radiation source and the frontal radiation detector along the vertical scanning direction, so that the frontal radiation detector at least provides:

[0025] o a first frontal exploration view, corresponding to a first portion of energy received by said frontal radiation detector and below a first given energy threshold, referred to as a low energy frontal exploration view,

[0026] o a second frontal exploration view, corresponding to a second portion of the energy received by said frontal radiation detector and being above a second given energy threshold, referred to as a high energy frontal exploration view,

[0027] The first frontal exploratory view and the second frontal exploratory view are combined and processed to evaluate:

[0028] ○At least the patient's bone thickness,

[0029] ○At least the patient's soft tissue thickness,

[0030] o patient-specific bone positioning at different imaging positions along the vertical scanning direction,

[0031] A frontal image is obtained by vertically scanning a standing patient along the vertical scanning direction by the frontal radiation source and by the frontal radiation detector, wherein:

[0032] o modulating the intensity of the driving current of at least the frontal radiation source along the vertical scanning direction according to the patient's bone thickness, according to the patient's soft tissue thickness and according to the patient's specific bone positioning at different imaging positions along the vertical scanning direction,

[0033] and preferably also modulating the intensity of the driving voltage of the frontal radiation source along the vertical scanning direction according to the patient's bone thickness, according to the patient's soft tissue thickness and according to the patient's specific bone positioning at different imaging positions along the vertical scanning direction,

[0034] o Automatically modulate the intensity of the driving current of the front radiation source without modulating the intensity of the voltage of the front radiation source in order to improve the compromise between:

[0035] ■ the total radiation dose received by the patient during said vertical scan,

[0036] ■ and for the en face image, the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction,

[0037] o or simultaneously, preferably synchronously and automatically, the driving current intensity modulation and voltage intensity modulation of the front radiation source are performed in order to improve the compromise between:

[0038] ■ the total radiation dose received by the patient during the vertical scan,

[0039] ■ and, for the en face image, the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction.

[0040] A second object of the present invention relates to a lateral single-energy or multi-energy scanning image performed after the lateral multi-energy exploration view.

[0041] This second object is achieved using a radiographic method comprising:

[0042] Two radiation sources, one front radiation source and one side radiation source, whose imaging directions are orthogonal to each other, the radiation sources slide vertically so as to perform vertical scanning on a standing patient along a vertical scanning direction,

[0043] two radiation detectors respectively associated with the two radiation sources, a front radiation detector and a side radiation detector, the radiation detectors vertically sliding so as to vertically scan a standing patient along the vertical scanning direction, at least the side radiation detector being a multi-energy counting detector,

[0044] The radiation method comprises at least one operating mode in which:

[0045] A lateral multi-energy exploration view is obtained by performing a preliminary vertical scan on a standing patient along the vertical scanning direction by the lateral radiation source and the lateral radiation detector, so that the lateral radiation detector at least provides:

[0046] o a first side exploration view, corresponding to a first portion of the energy received by said side radiation detector and below a first given energy threshold, referred to as a low energy side exploration view,

[0047] o a second side exploration view corresponding to a second portion of the energy received by said side radiation detector and being above a second given energy threshold, referred to as a high energy side exploration view,

[0048] The first lateral exploratory view and the second lateral exploratory view are combined and processed to evaluate:

[0049] ○At least the patient's bone thickness,

[0050] ○At least the patient's soft tissue thickness,

[0051] o patient-specific bone positioning at different imaging positions along the vertical scanning direction,

[0052] A lateral image is obtained by vertically scanning a standing patient along the vertical scanning direction by the lateral radiation source and by the lateral radiation detector, wherein:

[0053] o modulating the intensity of the driving current of at least the side radiation source along the vertical scanning direction according to the patient's bone thickness, according to the patient's soft tissue thickness and according to the patient's specific bone positioning at different imaging positions along the vertical scanning direction,

[0054] and preferably also modulating the intensity of the driving voltage of the side radiation source along the vertical scanning direction according to the patient's bone thickness, according to the patient's soft tissue thickness and according to the patient's specific bone positioning at different imaging positions along the vertical scanning direction,

[0055] o Automatically modulate the intensity of the driving current of the side radiation source without modulating the intensity of the voltage of the side radiation source in order to improve the compromise between:

[0056] ■ the total radiation dose received by the patient during said vertical scan,

[0057] ■ and for the lateral image, the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction,

[0058] o or simultaneously, preferably synchronously and automatically, the driving current intensity modulation and voltage intensity modulation of the side radiation source are performed to improve the compromise between:

[0059] ■ the total radiation dose received by the patient during the vertical scan,

[0060] ■ and, for the lateral image, the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction.

[0061] The third object of the present invention relates to frontal and lateral (single energy or multi-energy) scan images taken after both the frontal multi-energy exploration view and the lateral multi-energy exploration view.

[0062] This third object is achieved using a radiological imaging method comprising:

[0063] Two radiation sources, one front radiation source and one side radiation source, whose imaging directions are orthogonal to each other, the radiation sources slide vertically so as to perform vertical scanning on a standing patient along a vertical scanning direction,

[0064] two radiation detectors respectively associated with the two radiation sources, a front radiation detector and a side radiation detector, the radiation detectors vertically sliding so as to vertically scan a standing patient along the vertical scanning direction, the two radiation detectors being two multi-energy counting detectors,

[0065] The radiation method comprises at least one operating mode in which:

[0066] A front multi-energy exploration view and a side multi-energy exploration view are obtained by performing a preliminary vertical scan on a standing patient along the vertical scanning direction by the front radiation source and the side radiation source and by the front radiation detector and the side radiation detector, so that the front radiation detector and the side radiation detector at least provide:

[0067] o a first frontal exploration view, corresponding to a first portion of energy received by said frontal radiation detector and below a first given energy threshold, referred to as a low energy frontal exploration view,

[0068] o a second frontal exploration view, corresponding to a second portion of the energy received by said frontal radiation detector and being above a second given energy threshold, referred to as a high energy frontal exploration view,

[0069] o a first side exploration view, corresponding to a first portion of the energy received by said side radiation detector and below a first given energy threshold, referred to as a low energy side exploration view,

[0070] o a second side exploration view corresponding to a second portion of the energy received by said side radiation detector and being above a second given energy threshold, referred to as a high energy side exploration view,

[0071] The first front exploratory view and the first lateral exploratory view and the second front exploratory view and the second lateral exploratory view are combined and processed to evaluate:

[0072] ○At least the patient's bone thickness,

[0073] ○At least the patient's soft tissue thickness,

[0074] o patient-specific bone positioning at different imaging positions along the vertical scanning direction,

[0075] A frontal image is obtained by vertically scanning a standing patient by the frontal radiation source and by the frontal radiation detector along the vertical scanning direction, and a lateral image is obtained by vertically scanning a standing patient by the lateral radiation source and by the lateral radiation detector along the vertical scanning direction, both the frontal image and the lateral image being obtained during the same vertical scan, wherein:

[0076] o modulating the drive current intensity of both the front radiation source and the side radiation source along the vertical scanning direction according to the patient's bone thickness, according to the patient's soft tissue thickness and according to the patient's specific bone positioning at different imaging positions along the vertical scanning direction,

[0077] and preferably also modulating the driving voltage intensity of both the front radiation source and the side radiation source along the vertical scanning direction according to the patient's bone thickness, according to the patient's soft tissue thickness and according to the patient's specific bone positioning at different imaging positions along the vertical scanning direction,

[0078] o At the same time, preferably synchronously and automatically, the intensity modulation of the driving current of the front radiation source without the voltage intensity modulation of the front radiation source and the intensity modulation of the driving current of the side radiation source without the voltage intensity modulation of the side radiation source are performed in order to improve the compromise between:

[0079] ■ the total radiation dose received by the patient during said vertical scan,

[0080] ■ and, for the frontal image and the lateral image, the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction,

[0081] o or simultaneously, preferably synchronously and automatically, the driving current intensity modulation and the voltage intensity modulation of the front radiation source, and simultaneously, preferably synchronously and automatically, the driving current intensity modulation and the voltage intensity modulation of the side radiation source, so as to improve the compromise between:

[0082] ■ the total radiation dose received by the patient during said vertical scan,

[0083] ■ And the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction for the frontal image and the lateral image.

[0084] Preferred embodiments include one or more of the following features, which may be employed alone or in combination in part or in whole with any of the aforementioned objects of the invention.

[0085] Preferably,

[0086] The frontal multi-energy exploration view is obtained by performing a single preliminary vertical scan on a standing patient by the frontal radiation source and by the frontal radiation detector along the vertical scanning direction, so that the frontal radiation detector at least gives:

[0087] ○The first frontal exploratory view,

[0088] ○The second frontal exploratory view,

[0089] The lateral multi-energy exploration view is obtained by performing a single preliminary vertical scan on a standing patient along the vertical scanning direction by the lateral radiation source and by the lateral radiation detector, so that the lateral radiation detector at least gives:

[0090] o The first side profile view,

[0091] ○The second side exploratory view,

[0092] Both the frontal multi-energy probing view and the lateral multi-energy probing view are obtained during the same single preliminary vertical scan.

[0093] Thus, since both the frontal and lateral exploratory views are taken simultaneously during the same single vertical scan, the frontal and lateral exploratory views will correspond topologically precisely to each other since a standing patient will not move therebetween.

[0094] Preferably,

[0095] The frontal image is obtained by performing a single vertical scan of a standing patient by the frontal radiation source and by the frontal radiation detector along the vertical scanning direction,

[0096] The lateral image is obtained by performing a single vertical scan of a standing patient along the vertical scanning direction by the lateral radiation source and by the lateral radiation detector,

[0097] Both the frontal image and the lateral image are obtained during the same single vertical scan.

[0098] Thus, since both the frontal and lateral images are taken simultaneously during the same vertical scan, the frontal and lateral images will correspond topologically exactly to each other since a standing patient will not move therebetween.

[0099] Preferably, the first given energy threshold is equal to or less than the second given energy threshold, preferably equal to the second given energy threshold.

[0100] Thus, in both cases, all energy threshold ranges are covered, with lower costs in the second case.

[0101] Preferably,

[0102] The first given energy threshold is equal to the second given energy threshold,

[0103] The front multi-energy probing view and / or the side multi-energy probing view are obtained so that the front radiation detector and / or the side radiation detector firstly gives:

[0104] ○The first frontal exploratory view,

[0105] o a third frontal exploration view, corresponding to the total energy received by the frontal radiation detector, referred to as the total energy frontal exploration view,

[0106] ■ obtaining the second frontal exploratory view by subtracting the first frontal exploratory view from the third frontal exploratory view,

[0107] ○ and / or said first lateral exploration view,

[0108] o and / or a third side profile view, which corresponds to the total energy received by said side radiation detector, referred to as a total energy side profile view,

[0109] ■ The second lateral exploratory view is obtained by subtracting the first lateral exploratory view from the third lateral exploratory view.

[0110] Therefore, the total energy exploration view and the high energy exploration view may be given directly by the detector, while the low energy exploration view may be obtained by a simple subtraction, by subtracting the high energy exploration view from the total energy exploration view.

[0111] Preferably,

[0112] combining and processing the first frontal exploratory view and / or the first lateral exploratory view and the second frontal exploratory view and / or the second lateral exploratory view to evaluate a bone thickness distribution of the patient along the vertical scanning direction,

[0113] and / or combining and processing the first frontal exploratory view and / or the first lateral exploratory view and the second frontal exploratory view and / or the second lateral exploratory view so as to evaluate the patient's soft tissue thickness distribution along the vertical scanning direction,

[0114] The frontal image is obtained by vertically scanning a standing patient along the vertical scanning direction by the frontal radiation source and by the frontal radiation detector, wherein:

[0115] ○ According to the patient's bone thickness distribution and / or the patient's soft tissue thickness distribution along the vertical scanning direction, modulating the driving current intensity of at least the front radiation source along the vertical scanning direction,

[0116] ○ And preferably, the driving voltage intensity of the front radiation source is modulated along the vertical scanning direction according to the patient's bone thickness distribution and the patient's soft tissue thickness distribution along the vertical scanning direction,

[0117] The side image is obtained by vertically scanning a standing patient along the vertical scanning direction by the side radiation source and by the side radiation detector, wherein:

[0118] ○ According to the patient's bone thickness distribution and / or the patient's soft tissue thickness distribution along the vertical scanning direction, modulating the driving current intensity of at least the side radiation source along the vertical scanning direction,

[0119] ○ And preferably, the driving voltage intensity of the side radiation source is modulated along the vertical scanning direction according to the patient's bone thickness distribution and the patient's soft tissue thickness distribution along the vertical scanning direction,

[0120] Both the frontal image and the lateral image are obtained during the same vertical scan.

[0121] Thus, since both the frontal and lateral images are taken simultaneously during the same vertical scan, the frontal and lateral images will correspond topologically exactly to each other since a standing patient will not move therebetween.

[0122] Preferably,

[0123] o Automatically modulating the intensity of the driving current of the front radiation source and / or the side radiation source without modulating the intensity of the voltage of the front radiation source and / or the side radiation source, so as to improve the compromise between:

[0124] ■ reducing the total radiation dose received by the patient during the vertical scan,

[0125] and for the frontal image and / or the lateral image, for all or part of the patient thickness along the vertical scanning direction, not reducing the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction at a given contrast threshold,

[0126] o or simultaneously, preferably synchronously and automatically, both the driving current intensity modulation and the voltage intensity modulation of the front radiation source and / or the side radiation source are performed in order to improve the compromise between:

[0127] ■ reducing the total radiation dose received by the patient during the vertical scan,

[0128] ■And for the frontal image and / or the lateral image, for all or part of the patient thickness along the vertical scanning direction, the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction is increased relative to the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction with the same total radiation dose but without any drive current intensity modulation or any drive voltage intensity modulation.

[0129] This means that it is possible to:

[0130] - Achieve the lowest possible total radiation dose while maintaining the correct predetermined image quality,

[0131] - or improve image quality without increasing the total radiation dose too much,

[0132] - Or even, the margin given by the invention can be allocated partly to reduce the radiation dose and partly to maintain a predetermined image quality.

[0133] Preferably,

[0134] o Automatically modulating the intensity of the driving current of the front radiation source and / or the side radiation source without modulating the intensity of the voltage of the front radiation source and / or the side radiation source, so as to improve the compromise between:

[0135] ■ reducing the total radiation dose received by the patient during the vertical scan,

[0136] and for the frontal image and / or the lateral image, for all or part of the patient thickness along the vertical scanning direction, improving the contrast-to-noise ratio or the ratio between the contrast-to-noise ratio and the square root of the total radiation dose at different imaging positions along the vertical scanning direction relative to the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction with the same total radiation dose but without any drive current intensity modulation,

[0137] o or simultaneously, preferably synchronously and automatically, both the driving current intensity modulation and the voltage intensity modulation of the front radiation source and / or the side radiation source are performed in order to improve the compromise between:

[0138] ■ reducing the total radiation dose received by the patient during the vertical scan,

[0139] ■And for the frontal image and / or the lateral image, for all or part of the patient thickness along the vertical scanning direction, the contrast-to-noise ratio of the identified specific bone location at different imaging positions along the vertical scanning direction or the ratio between the contrast-to-noise ratio and the square root of the total radiation dose is improved relative to the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction with the same total radiation dose but without any drive current intensity modulation or any drive voltage intensity modulation.

[0140] This means that it is possible to:

[0141] - Achieve the lowest possible total radiation dose while maintaining the intended good image quality,

[0142] - or profoundly improve image quality without increasing total radiation dose,

[0143] - Or even, the margin given by the invention can be allocated partly to reduce the radiation dose and partly to maintain a better predetermined image quality.

[0144] Preferably,

[0145] The frontal multi-energy exploration view is acquired by using at least 2 energy bins, or by using at least 3 energy bins, or by using at least 6 energy bins.

[0146] ○ and / or up to 20 energy bins, or up to 15 energy bins, or up to 10 energy bins,

[0147] and / or using at least 2 energy bins or using at least 3 energy bins or using at least 6 energy bins to acquire the side multi-energy exploration view,

[0148] ○ and / or up to 20 energy bins, or up to 15 energy bins, or up to 10 energy bins.

[0149] Thus, the higher the number of bins, the more accurately different tissue textures within a patient's body can be distinguished from one another, but at the expense of increased system complexity, and with the risk that for each bin a less useful signal becomes available.

[0150] Preferably,

[0151] processing the first front side exploration view and the second front side exploration view as a multi-material decomposition having at least two vertical distributions of material thickness,

[0152] ○ Preferably, a bi-material decomposition between Al and PMMA, or a bi-material decomposition between HA (hydroxyapatite) and H2O,

[0153] and / or processing the first side exploration view and the second side exploration view as a multi-material decomposition with at least two material thickness vertical vectors,

[0154] ○ Preferably, a bi-material decomposition between Al and PMMA, or a bi-material decomposition between HA and H2O.

[0155] In fact, on one side, Al or HA presents X-ray attenuation properties close to those of human bone, while on the other side, PMMA or H2O presents X-ray attenuation properties close to those of human soft tissue.

[0156] Preferably,

[0157] For each of said radiation detectors:

[0158] o The radiation detector pixel size is in the range of 50 μm to 250 μm, or in the range of 80 μm to 150 μm, or is about 100 μm,

[0159] ○ and / or the total height of the radiation detector is in the range of 0.1 cm to 1.2 cm, or 0.2 cm to 1.0 cm, or 0.3 cm to 0.7 cm,

[0160] o and / or the total width of the radiation detector is in the range of 10 cm to 80 cm, or 20 cm to 70 cm, or 30 cm to 60 cm,

[0161] ○ And / or the radiation detector can operate in a time delay and sum mode.

[0162] As a result, the image will have better resolution without too many artifacts and will cover the total useful width of the patient.

[0163] Preferably, said identified specific skeletal location comprises the patient's spine, preferably the patient's spine.

[0164] Indeed, for orthopedic imaging purposes, the patient's spine is the specific bony location within the patient's body that is most worthy of detailed analysis; therefore, it is used for driving current intensity modulation.

[0165] Alternatively, the specific bone location may also be the pelvis or an arm or a leg of a standing patient along a vertical scanning direction, depending on the region of interest within the portion of the patient's body being imaged.

[0166] Preferably, both the driving current intensity modulation and the voltage intensity modulation of the front radiation source and / or the side radiation source are also performed so as to achieve a certain signal-to-noise ratio value, which, for the front image and / or for the side image, is constant and common for most of the imaging positions along the vertical scanning direction, preferably for all the imaging positions along the vertical scanning direction, but can take two different values ​​for the front image and for the side image, respectively.

[0167] Preferably, for each of the frontal image and / or the lateral image, the signal-to-noise ratio value is constant and predetermined for each different patient organ to be imaged.

[0168] Preferably,

[0169] for a frontal image of the patient's spine, said standard signal-to-noise ratio value corresponds to a number of X-ray photons received per detector pixel comprised between 50 and 70, said radiographic imaging method operator having a probability, preferably via manual command, of deviating from this standard value by at least -25% or +100%, more preferably by at least -50% or +200%,

[0170] And / or for a lateral image of the patient's spine, the standard signal-to-noise ratio value corresponds to a number of X-ray photons received by each detector pixel comprised between 20 and 40, and the operator of the radiographic imaging method preferably has the possibility of deviating from this standard value by at least -25% or +100%, more preferably by at least -50% or +200%, via manual command.

[0171] Thus, with a constant and optimized signal-to-noise ratio along or even all the way along the vertical scanning direction, the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction is greatly improved, especially since this is the area of ​​actual interest within the frontal image and / or lateral image.

[0172] Preferably, the front image and / or the side image are normalized by homogenization of the original radiation after undergoing at least the local image contrast improvement so as to eliminate image artifacts from the drive current intensity modulation and the voltage intensity modulation, and preferably wherein the front image and / or the side image undergo a contrast enhancement step after having been normalized.

[0173] In fact, due to this drive modulation, there are some artifacts in the frontal and / or lateral images which superimpose on the images some modulation patterns of sharp and dark grey levels, making these images somewhat unsatisfactory for the interpretation by a radiographic method operator or practitioner.

[0174] Preferably, said identified specific bone location excludes metal parts, if any, such as metal prostheses of skeletal parts of the patient's body or metal protectors placed on the patient's body, for example, prior to performing said radiographic method.

[0175] In fact, these foreign (for the patient's body) objects introduced into or on the patient's body, being metallic and therefore blocking more radiation (X-rays) than the rest of the patient's body, may lead to some poor optimization of the emitted dose, with the risk of some overexposure of the emitted radiation for the height corresponding to these foreign objects. If the metallic outliers are not excluded with constant drive voltage intensity, the consequences may be even worse, since more or all parameters are chosen for maximum thickness, leading to the emission of a radiation dose higher or much higher than required, which would be detrimental to the patient.

[0176] Preferably,

[0177] Modulate both the current and voltage:

[0178] o Increase both current and voltage intensity for greater patient thickness,

[0179] o Reduce both current and voltage intensity for smaller patient thicknesses,

[0180] ○The rate of change of current intensity is slower than the rate of change of voltage intensity.

[0181] Hence, all parts of the patient's body can be fully optimized with respect to the trade-off between total radiation dose (preferably lowest possible) and image quality (preferably highest possible).

[0182] Preferably, the current intensity modulation is maximized so as to also maximize the vertical scanning speed to a constant value.

[0183] Therefore, for a given emitted radiation dose, and therefore for a given radiation dose received by a standing patient during said vertical scan, both are kept at the same level, the total vertical scan time is significantly reduced, with the advantage of reducing the likelihood of movement of the standing patient and the effects of patient motion, thereby reducing to a certain extent the risk of blurring and deformation of the frontal and lateral images.

[0184] Preferably, the operating mode can be switched on or off manually by an operator of the radiographic method.

[0185] Thus, this very advantageous way of operating the radiographic device is available, and if and when the operator of this radiographic device wants to remove this way, it can be cancelled, so as to operate this radiographic device, for example, completely manually. The radiographic method according to an advantageous embodiment of the invention presents 3 operating modes: completely manual mode, AEC mode without modulation (AEC=Automatic Exposure Control), AEC mode with modulation.

[0186] Preferably, the operating mode is applicable to patient morphology types ranging from children to obese adults and is dedicated to vertical scanning of large and / or obese patients, and / or wherein the operating mode is dedicated to vertical scanning of pediatric patients.

[0187] The radiographic method according to the invention is of particular interest for situations when the patient may be particularly thinner or thicker than an average-sized patient. This demonstrates the ability of the radiographic method according to the invention to be very patient-specific and to take into account a wide attenuation range in long-axis imaging. Of course, the radiographic method according to the invention also works very well for standard-sized patients.

[0188] Preferably, the current intensity modulation rate does not exceed a predetermined threshold of 5 mA per millisecond, or does not exceed a predetermined threshold of 2 mA per millisecond, or does not exceed a predetermined threshold of 1 mA per millisecond.

[0189] Therefore, the radiographic method according to the invention can also be performed using relatively simple and inexpensive radiation sources having a relatively slow current intensity drive capability.

[0190] Preferably, the current intensity modulation is at least in the range of 20 mA to 300 mA, and preferably 10 mA to 400 mA.

[0191] Therefore, the radiographic method according to the invention can also be performed using relatively simple and inexpensive radiation sources having a relatively limited range of current intensity drive capabilities.

[0192] Preferably, the voltage intensity modulation is at least in the range of 60 kV to 100 kV, preferably in the range of 50 kV to 130 kV.

[0193] Therefore, the radiographic method according to the invention can also be performed with relatively simple and inexpensive radiation sources having a relatively limited range of voltage intensity drive capabilities, while at the same time fully utilizing the available range of voltage intensity drive capabilities.

[0194] Preferably, the vertical scanning speed value is at least in the range of 8 cm / sec to 20 cm / sec, and preferably 0.4 cm / sec to 35 cm / sec.

[0195] Therefore, the radiographic imaging method according to the invention can also be performed using relatively simple and inexpensive radiation sources having a relatively limited range of vertical scanning speed capabilities, while at the same time fully utilizing the available range of vertical scanning speed capabilities.

[0196] Preferably, before obtaining each of the frontal image and the side image, each of the frontal exploratory views and / or the side exploratory views is obtained by performing a preliminary vertical scan on a standing patient along a vertical scanning direction with a total radiation dose reduced compared to each of the frontal image and the side image, and preferably wherein the reduced total radiation is less than 10% of the total radiation dose, and more preferably less than 5% of the total radiation dose.

[0197] Thus, depending on the thickness distribution and on the specific bone positioning of the patient's standing body along the vertical scanning direction, the modulation of the drive current intensity and possibly the vertical scanning speed can be determined only before the vertical scanning is performed, which will result in effective frontal and lateral images of the standing patient's body at a limited but sufficient radiation dose sufficient to obtain high-quality frontal and lateral images. The exploration view can be performed at the expense of a fairly limited overexposure of the emitted radiation. The benefit can even be twofold: not only is the overexposure (+10% or +5%) during the exploration view very limited, but it is also very effective for optimizing the compromise between the total radiation dose received and the enhancement of the image contrast.

[0198] Preferably, the pixels in the exploration view are grouped together to obtain an imaging area, preferably in areas of N×N pixels, more preferably in areas in the range of 2×2 pixels to 10×10 pixels.

[0199] Thus, image quality and image contrast are enhanced for the exploratory view, despite the very low level of emitted radiation dose used to perform this exploratory view.

[0200] Preferably, the image or the imaging region is processed to identify salient points which are in turn used to calculate the thickness distribution and identify the specific bone location along the vertical scanning direction in a standing patient.

[0201] Therefore, despite the very low level of transmitted radiation dose, it is easier and more efficient to calculate the thickness distribution and identify the specific bone location along the vertical scanning direction for a standing patient from a exploratory view.

[0202] Preferably, said image or said imaging region is processed by a neural network to calculate said thickness distribution and identify said specific bone location along said vertical scanning direction of a standing patient.

[0203] Therefore, despite the very low level of transmitted radiation dose, it is easier and more effective to identify said specific bone location along the vertical scanning direction of a standing patient from a exploratory view.

[0204] Preferably, the two radiation sources slide vertically so as to vertically scan the pelvis or spine or the whole body of a standing patient along a vertical scanning direction.

[0205] Preferably, the two radiation detectors are respectively associated with the two radiation sources, and the two radiation detectors are two photon counting detectors (PCDs), each of which is associated with an automatic image processing function, which automatically balances the image grayscale level to make the response of the detector uniform regardless of the radiation dose received on the sensitive surface of the radiation detector.

[0206] This is an interesting feature since it is more difficult for a radiographic method operator to correctly manually assess overexposure or underexposure of the radiation signal emitted by the radiation source. Furthermore, photon counting detectors exhibit improved linearity and signal-to-noise ratio relative to the X-ray flux compared to gas detectors.

[0207] Preferably, the two radiation detectors are respectively associated with the two radiation sources, and the two radiation detectors are two multi-energy counting detectors, preferably two energy-resolved photon counting detectors (ERPCD).

[0208] Preferably, the radiation is X-rays.

[0209] A standing patient or a patient in a standing position is a patient in a weight-bearing position, which is the opposite of a lying patient or a patient in a lying position as in a computed tomography scan. Another patient weight-bearing position alternative to the patient standing position may be a patient sitting position.

[0210] Preferably, the second energy threshold is selected so as to improve image contrast more for lower patient thickness regions along the vertical direction than for higher patient thickness regions along the vertical direction, preferably the second energy threshold is between 50keV and 90keV, preferably selected between 60keV and 80keV, more preferably the second energy threshold is selected at 70keV.

[0211] Thus, even though a wider patient chest may still be accurately seen, a narrower arm or leg will not be sacrificed by being undersaturated at all or very lightly saturated (ie, overexposure due to system limitations).

[0212] Preferably, the first energy threshold and / or the second energy threshold are modified according to the patient bone thickness and / or according to the patient soft tissue thickness and / or according to the patient-specific bone positioning at different imaging positions along the vertical scanning direction, and / or associated spectral filtering, preferably k-edge filtering, is used and tuned.

[0213] Thus, even the accuracy of the end-user images used by practitioners is improved.

[0214] Preferably,

[0215] The front image and / or the side image are both single-energy images obtained by modulating the voltage intensity of the front radiation source and / or the side radiation source.

[0216] Or the front image and / or the side image are / is a multi-energy image of the front radiation source and / or the side radiation source without voltage intensity modulation.

[0217] Therefore, in order to obtain good image quality with a reduced total radiation dose, the detector recording the image is simpler but the modulation is more complex, or the detector recording the image is more complex but the modulation is simpler.

[0218] Advantageously, the multi-energy probing view is a dual-energy probing view.

[0219] For all the aforementioned objects of the invention and / or for all the aforementioned combinations, a mechanical cross scatter correction with vertical gap may be added, as described, for example, in patent applications EP 16711889 or US 1607660, and / or a software cross scatter correction, as described, for example, in patent applications EP 17758269 or US 16628410, all of which are incorporated by reference and are owned by the same applicant.

[0220] For all the aforementioned objects of the present invention and / or for all the aforementioned combinations, some common signal processing may be added and / or adapted, such as signal preprocessing or signal post-processing as disclosed in patent application WO2021 / 094806 or patent application WO2021 / 094404, which are incorporated by reference and are owned by the same applicant.

[0221] The present invention aims to provide a solution for providing an AEC system to a scanning stereo radiography system, the AEC being compliant with the IEC 62494-1 standard.

[0222] PMMA is poly(methyl methacrylate), a thermoplastic commonly used as a glass substitute. Al is aluminum.

[0223] Further characteristics and advantages of the invention will become apparent from the following description of embodiments of the invention given as non-limiting examples, with reference to the accompanying drawings listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0224] Figure 1 An example of an imaging workflow of a radiological imaging method according to an embodiment of the present invention is shown, which has current modulation but no voltage modulation.

[0225] Figure 2 Another example of an imaging workflow of a radiological imaging method according to an embodiment of the present invention is shown, which has both current modulation and voltage modulation.

[0226] Figure 3 An example of a multi-energy exploration view acquisition step in a radiological imaging method according to an embodiment of the present invention is shown.

[0227] Figure 4 Another example of the multi-energy exploration view acquisition step in the radiological imaging method according to the embodiment of the present invention is shown.

[0228] Figure 5 An example of a bone localization calculation step with distribution of interest extraction in a radiological imaging method according to an embodiment of the present invention is shown.

[0229] Figure 6 An example of a portion of a patient bone and soft tissue thickness calculation step within a radiological imaging method according to an embodiment of the present invention is shown.

[0230] Figure 7 An example of another part of the patient bone and soft tissue thickness calculation step within the radiological imaging method according to an embodiment of the present invention is shown.

[0231] Figure 8 The relationship between the total thickness, PMMA thickness and Al thickness is shown.

[0232] Fig. 9 An example of a CNRD calculation step on a search space within a radiological imaging method according to an embodiment of the present invention is shown.

[0233] Fig.10 An example of an optimal kV mapping step within a radiological imaging method according to an embodiment of the present invention is shown.

[0234] Fig.11 An example of a normalization step within a radiological imaging method according to an embodiment of the present invention is shown, which shows a frontal unnormalized image of a patient.

[0235] Fig.12 An example of a normalization step within a radiological imaging method according to an embodiment of the present invention is shown, which shows a patient frontal raw radiation image.

[0236] Fig.13 An example of a normalization step within a radiological imaging method according to an embodiment of the present invention is shown, which shows a patient frontal normalized image.

[0237] Fig.14 An example of a normalization step within a radiological imaging method according to an embodiment of the present invention is shown, which shows a non-normalized image of a patient's side.

[0238] Fig.15 An example of a normalization step within a radiological imaging method according to an embodiment of the present invention is shown, which shows a patient side raw radiation image.

[0239] Fig.16An example of a normalization step within a radiological imaging method according to an embodiment of the present invention is shown, which shows a patient-side normalized image.

[0240] Fig.17 An example of a single energy probing view with a signal-to-PMMA mapping obtained only by a radiographic method not according to an embodiment of the present invention is shown.

[0241] Fig.18 An example of a multi-energy probing view with signal-to-PMMA and signal-to-AI mappings obtained by a radiological imaging method according to an embodiment of the present invention is shown.

[0242] Fig.19 An example of a simulation of expected tube power distribution with front single energy probing views and side single energy probing views, with current modulation but without voltage modulation, not according to an embodiment of the present invention is shown.

[0243] Fig. 20 Shown corresponding to Fig.19 Example of current modulation distribution.

[0244] Fig.21 Shown corresponding to Fig.19 An example of a fixed value of voltage.

[0245] Fig. 22 Shown corresponding to Fig.19 An example of the distribution of frontal bone localization along the contour of a patient of interest.

[0246] Fig.23 Shown corresponding to Fig.19 An example of the distribution of lateral bone localization along the contour of a patient of interest.

[0247] Fig.24 An example of a simulation of the expected tube power distribution with front and side single energy probing views, with both current modulation and voltage modulation, is shown not in accordance with an embodiment of the present invention.

[0248] Fig.25 Shown corresponding to Fig.24 Example of current modulation distribution.

[0249] Fig.26 Shown corresponding to Fig.24 Example of voltage modulation distribution.

[0250] Fig. 27 Shown corresponding to Fig.24 An example of the distribution of frontal bone localization along the contour of a patient of interest.

[0251] Fig.28 Shown corresponding to Fig.24An example of the distribution of lateral bone localization along the contour of a patient of interest.

[0252] Fig.29 An example of a simulation of expected tube power distribution with front and side multi-energy probing views, with both current modulation and voltage modulation, according to an embodiment of the present invention is shown.

[0253] Fig.30 Shown corresponding to Fig.29 Example of current modulation distribution.

[0254] Fig.31 Shown corresponding to Fig.29 Example of voltage modulation distribution.

[0255] Fig.32 Shown corresponding to Fig.29 An example of the distribution of frontal bone localization along the contour of a patient of interest.

[0256] Fig.33 Shown corresponding to Fig.29 An example of the distribution of lateral bone localization along the contour of a patient of interest.

[0257] Fig.34 An example of frontal bone location distribution along the contour of a patient of interest in a modulated image obtained by simulation is shown.

[0258] Fig.35 An example of lateral bone location distribution along the contour of a patient of interest in a modulated image obtained by simulation is shown.

[0259] Fig.36 An example of a simulation of the frontal signal distribution along the contour of a patient of interest is shown.

[0260] Fig.37 An example of a simulation of the frontal deviation index distribution along the contour of a patient of interest is shown.

[0261] Fig.38 An example of a simulation of the lateral signal distribution along the contour of a patient of interest is shown.

[0262] Fig.39 An example of a simulation of the distribution of the side deviation index along the contour of a patient of interest is shown.

[0263] Fig.40 An example of the structure of an imaging apparatus for implementing a radiation imaging method according to an embodiment of the present invention is shown.

[0264] Fig.41 An example of a region of a detector used for averaging during implementation of a radiographic method according to an embodiment of the invention is shown.

[0265] Fig.42 Showing an example of optimal kV mapping during a radiological imaging method not according to an embodiment of the present invention, the exploration view is mono-energy.

[0266] Fig.43 Showing an example of optimal kV mapping during a radiological imaging method according to an embodiment of the present invention, the exploration view is multi-energy.

[0267] Fig.44 An example of a deviation index graph showing optimal kV mapping during a radiological imaging method not according to an embodiment of the present invention, the exploration view being mono-energy.

[0268] Fig.45 An example of a deviation index graph showing optimal kV mapping during a radiological imaging method according to an embodiment of the present invention, the exploration view being multi-energy. DETAILED DESCRIPTION

[0269] In the following description, what is described from the frontal exploratory view or image may be similarly applied to the lateral exploratory view or image, respectively, and vice versa, unless mentioned to the contrary. If the practitioner or patient is only interested in the frontal exploratory view or only in the lateral exploratory view, all operations done on both the frontal exploratory view and the lateral exploratory view may be done only for the frontal exploratory view or only for the lateral exploratory view. If the practitioner or patient is only interested in the frontal image or only in the lateral image, all operations done on both the frontal image and the lateral image may be done only for the frontal image or only for the lateral image. Wherever distribution is mentioned, unless mentioned to the contrary, a sequence of several partial or regional averages (averages for each zone or organ, such as the leg, pelvis, spine, neck, head or parts thereof) or sometimes a single average may be sufficient, although the result will be less accurate.

[0270] Figure 1 An example of an imaging workflow of a radiological imaging method according to an embodiment of the present invention is shown, which has current modulation but no voltage modulation.

[0271] First, step 1 of acquiring a front exploratory view and a side exploratory view is performed.

[0272] Next, step 20 of thickness distribution extraction is performed based on the front exploration view and the side exploration view performed at the acquisition step 1. This step 20 includes a sub-step 21 of bone positioning calculation, wherein the extraction of the distribution of interest along the patient's height is performed in parallel and simultaneously with the sub-step 22 of calculating both the patient's bone thickness and the patient's soft tissue thickness, and then both the patient's bone thickness distribution and the patient's soft tissue thickness distribution along the patient's height are processed by extracting the corresponding thickness values ​​along the coordinates of the distribution of interest. In sub-step 21, the coordinates {x_i} (x_1, x_2...x_N) corresponding to the location of the point in the distribution of interest are extracted from the exploration view. In sub-step 22, the conversion between signal and thickness is performed, which produces a bone thickness image fBone and a soft tissue thickness image fSoft. The result of the combination of sub-steps 21 and 22 is a set of {fBone(x_i)} and {fSoft(x_i)}.

[0273] At the end of step thickness distribution extraction 20 , both the patient's bone thickness distribution and the patient's soft tissue thickness distribution along the patient's height are available for the next step, which is determination and selection step 23 .

[0274] Next, step 23 is performed to determine fixed voltage values ​​(in kV) and spectral filtering, as well as select detector energy thresholds, from a model and / or reference table 24 containing a catalog of models and / or references, based on the patient's bone thickness distribution and the patient's soft tissue thickness distribution along the patient's height. The model and / or reference table 24 gives an exposure target 25 corresponding to the model or reference selected in the determination and selection step 23. At the end of the determination and selection step 23, the spectral filtering, the fixed voltage value, and one or more detector energy thresholds are available for the next calculation step 26.

[0275] Subsequently, a calculation step 26 calculates the acquisition speed of the vertical scan along the height of the standing (or seated) patient and the current modulation distribution along the patient height. The calculation step 26 also uses the exposure target 25. The calculation step also performs a feedback loop towards the determination and selection step 23. At the end of the calculation step 26, the spectral filtering, fixed voltage value, one or more detector energy thresholds, the vertical scan acquisition speed (in mm / sec), the current modulation distribution in mA along the patient height can be used for the next image acquisition step 3. The current modulation distribution along the patient height will also be directly available for the image normalization step 4.

[0276] All steps 20 , 23 , 24 , 25 , 26 are part of the exposure parameter calculation routine 2 .

[0277] Next, after this exposure parameter calculation routine 2 has been fully completed, an image acquisition step 3 is performed based on spectral filtering, fixed voltage values, one or more detector energy thresholds, vertical scanning acquisition speed (in mm / second), and current modulation distribution along the patient height (in mA). This acquired image can be a single energy image or can be a multi-energy image. Preferably, this acquired image is a multi-energy image. The acquired image can include a frontal image and / or a side image. The acquired image preferably includes a frontal image and a side image.

[0278] Then, in the normalization step 4, the image acquired from the front and the image acquired from the side are normalized.

[0279] In a processing and display step 5, the front normalized image and the side normalized image may then be further processed (using a post-processing step) and / or subsequently displayed on a screen for viewing by a practitioner.

[0280] Figure 2 Another example of an imaging workflow of a radiological imaging method according to an embodiment of the present invention is shown, which has both current modulation and voltage modulation.

[0281] First, step 1 of acquiring a front exploratory view and a side exploratory view is performed.

[0282] Next, a step 20 of thickness distribution extraction is performed based on the frontal exploration view and the side exploration view performed at the acquisition step 21. This step 20 includes a sub-step 21 of bone positioning calculation, wherein the extraction of the distribution of interest along the patient's height is performed in parallel and simultaneously with the sub-step 22 of calculating both the patient's bone thickness and the patient's soft tissue thickness, and then both the patient's bone thickness distribution and the patient's soft tissue thickness distribution along the patient's height are processed by extracting the corresponding thickness values ​​along the coordinates of the distribution of interest. At the end of the step thickness distribution extraction 20, both the patient's bone thickness distribution and the patient's soft tissue thickness distribution along the patient's height can be used for the next step, which is a determination and selection step 23.

[0283] Next, step 23 is performed to determine the voltage modulation distribution (in kV = kilovolts) and spectral filtering along the patient's height, and select a detector energy threshold from a model and / or reference table 24 of a catalog containing models and / or references, based on the patient's bone thickness distribution and the patient's soft tissue thickness distribution along the patient's height. The model and / or reference table 24 gives an exposure target 25 corresponding to the model or reference selected in the determination and selection step 23. At the end of the determination and selection step 23, the spectral filtering, the voltage modulation distribution along the patient's height, and one or more detector energy thresholds are available for the next calculation step 26.

[0284] Next, a calculation step 26 calculates the acquisition speed of the vertical scan along the height of the standing (or seated) patient and the current modulation distribution along the patient height. The calculation step 26 also uses the exposure target 25. The calculation step also performs a feedback loop towards the determination and selection step 23. At the end of the calculation step 26, the spectral filtering, the voltage modulation distribution along the patient height, one or more detector energy thresholds, the vertical scan acquisition speed (in mm / second), the current modulation distribution along the patient height (in mA). The voltage modulation distribution along the patient height and the current modulation distribution along the patient height will also be directly available for the image normalization step 4, which can be used for the next image acquisition step 3.

[0285] All steps 20 , 23 , 24 , 25 , 26 are part of the exposure parameter calculation routine 2 .

[0286] Next, after this exposure parameter calculation routine 2 has been fully completed, an image acquisition step 3 is performed based on spectral filtering, voltage modulation distribution along patient height (in kV), one or more detector energy thresholds, vertical scan acquisition speed (in mm / sec), current modulation distribution along patient height (in mA). This acquired image can be a single energy image or can be a multi-energy image. Preferably, this acquired image is a multi-energy image, but it can also be a single energy image. The acquired image can include a frontal image and / or a side image. The acquired image preferably includes a frontal image and a side image.

[0287] Then, in the normalization step 4, the image acquired from the front and the image acquired from the side are normalized.

[0288] In a processing and display step 5, the front normalized image and the side normalized image may then be further processed (using a post-processing step) and / or subsequently displayed on a screen for viewing by a practitioner.

[0289] Figure 3 An example of a multi-energy exploration view acquisition step in a radiological imaging method according to an embodiment of the present invention is shown.

[0290] The normalized attenuation spectrum AS is presented as a function of the energy E in keV.

[0291] In the multiple energy survey view mode, the detector directly reads the low energy survey view and the high energy survey view, and derives the total energy survey view by adding the high energy survey view and the low energy survey view together.

[0292] In a single energy or single energy exploration view mode, there will only be a single bin which will correspond to the total energy bin.

[0293] Figure 4Another example of the multi-energy exploration view acquisition step in the radiological imaging method according to the embodiment of the present invention is shown.

[0294] The normalized attenuation spectrum AS is presented as a function of the energy E in keV.

[0295] In the multiple energy survey view mode, the detector reads the total energy survey view and the high energy survey view, and derives the low energy survey view by subtracting the high energy survey view from the total energy survey view.

[0296] In a single energy or single energy exploration view mode, there will only be a single bin which will correspond to the total energy bin.

[0297] Figure 5 An example of a bone localization calculation step with distribution of interest extraction in a radiological imaging method according to an embodiment of the present invention is shown.

[0298] exist Figure 5 There is an exploration view Figure 6 , here is the side view Figure 6 , where highlighted points 60 are positioned along a lateral image 6 of the patient skeleton, the highlighted points 60 representing the patient-specific bone positioning at different imaging positions along the vertical scanning direction, which is also here at the standing patient height.

[0299] These salient points 60 represent curves extracted from the patient side image 6 by summing up the detector signal values ​​in clinically significant anatomical landmarks along the slot scan. Thus, several processing techniques may be used, which may be based on image filtering and segmentation techniques, or on landmark extraction from machine learning techniques.

[0300] This is how sub-step 21 of the bone positioning calculation is performed.

[0301] Figure 6 An example of a portion of a patient bone and soft tissue thickness calculation step within a radiological imaging method according to an embodiment of the present invention is shown.

[0302] Each time through Figure 7 The online thickness calculation 222 of the online operation 222 uses the Figure 6 The offline signal to thickness mapping calibration offline operation 221 performs the sub-step 22 of calculating both the patient's bone thickness and soft tissue thickness based on the information obtained offline.

[0303] In an offline operation 221 of an offline signal-to-thickness mapping calibration, the exploration exposure parameters 2211 and the known material thickness 2212 are used as input to a measurement or simulation 2213, which gives a measured or simulated detector signal 2214 as an output. Next, both the known material thickness 2212 and the measured or simulated detector signal 2214 are saved and stored in a signal-to-thickness mapping database 2215. The offline-calculated signal-to-thickness mapping database 2215 contains mappings from detector signal counts to corresponding material thicknesses. These mappings can be, for example, lookup tables (LUTs) or model fits. In contrast to a single energy exploration view where the mapping is based on the total energy signal, the multi-energy exploration view mapping (here, dual energy exploration view mapping) is based on signal pairs, including both low energy signals and high energy signals, with one mapping calculated for each material: soft tissue for low energy signals and bone for high energy signals. PMMA thickness is stored in high energy and low energy coordinate systems. Al thickness is stored in high energy and low energy coordinate systems.

[0304] Figure 7 An example of another part of the patient bone and soft tissue thickness calculation step within the radiological imaging method according to an embodiment of the present invention is shown.

[0305] In the online operation 222 of the online thickness calculation, the measured detector signal 2221 is used as input to both the sub-database 2222 storing the signal to bone thickness mapping and to the sub-database 2224 storing the signal to soft tissue thickness mapping. The sub-database 2222 storing the signal to bone thickness mapping gives as output a bone thickness profile 2223. The sub-database 2224 storing the signal to soft tissue thickness mapping gives as output a soft tissue thickness profile 2225.

[0306] Figure 8 The relationship between the total thickness, PMMA thickness and Al thickness is shown. In the phantom or avatar used to establish the signal to thickness mapping database 2215 (including both the signal to bone sub-database 2222 and the soft tissue mapping sub-database 2224), the total thickness T PMMA+Al 230 is equal to T PMMA 232 and T Al 231. In the imaged patient body and in the corresponding image processed using the signal-to-thickness mapping database 2215 (including both the signal-to-bone sub-database 2222 and the soft tissue mapping sub-database 2224), the total thickness T soft tissue+bone 230 is equal to T soft tissue 232 and T bone The sum of 231.

[0307] Based on the patient's bone thickness profile and the patient's soft tissue thickness profile along the patient's height, the step 23 of determining the voltage modulation distribution (in kV) along the patient's height and the spectral filtering and selecting the detector energy threshold from a model and / or reference table 24 of a catalog containing models and / or references is based on a mapping from material thickness to voltage values ​​expressed in kV (kilovolts). This mapping can be given by an empirically fine-tuned lookup table as a first alternative, or optimally determined according to task metrics as a second alternative.

[0308] In the second alternative, the task metrics should preferably satisfy at most the following rules:

[0309] - is constant with respect to the product of the tube current and the exposure time or is at least a monotonic function of the product of the tube current and the exposure time (expressed in milliampere-seconds mAs),

[0310] - represents how well the task is performed as a function of voltage and material thickness (a one-dimensional vector in the case of a single energy probing view, or a multi-dimensional vector in the case of a multi-energy probing view as in the present invention): the better the task, the higher the metric,

[0311] - It is meaningful in the entire slot scan, ie along the entire distribution of interest.

[0312] This task metric is expressed as in is a vector of additional data-dependent parameters, such as single or multi-material thickness distribution, or tube spectrum filtering options for image acquisition. The optimal kV selection is equivalent to selecting

[0313] This map is calculated offline and saved, for example as a lookup table or as a model fit. In addition to this map, the product of each tube current and exposure time (in mAs) is also calculated. A mapping of the detector exposure target (e.g., detector signal) is saved as, for example, a lookup table or a model fit. Used in task metrics.

[0314] By way of illustration, a specific example of a task metric for voltage kV optimization in the context of dual energy probing views, referred to as CNR to Dose Ratio (CNRD), is now described.

[0315] As an example, consider a two material basis (PMMA, Al) provided by a dual energy probing view.

[0316] The task then is twofold:

[0317] - Maximize the local contrast resolution of the Al material surrounded by PMMA,

[0318] - Minimize the entrance dose required to achieve a unit detector signal value behind the (PMMA, Al) projection line (corresponding to the content of the ALARA principle).

[0319] Local contrast resolution can be measured by the contrast-to-noise ratio (CNR):

[0320]

[0321] The incoming dose can be monitored by using the spectral air kerma value D.

[0322] Then CNRD is defined as:

[0323]

[0324] It is independent of the product of tube current and exposure time.

[0325] Fig. 9 An example of a CNRD calculation step on a search space within a radiological imaging method according to an embodiment of the present invention is shown.

[0326] A database of CNRD graphs 234 is searched for a particular voltage value, each CNRD graph being a function of both Al thickness and PMMA thickness.

[0327] Fig.10 An example of an optimal kV mapping step within a radiological imaging method according to an embodiment of the present invention is shown.

[0328] The database of CNRD graphs 234 has been searched to obtain an optimum voltage (kV) graph 235, which is a graph showing the optimum voltage as a function of both Al thickness and PMMA thickness.

[0329] Fig. 9 and Fig.10 The optimization shown works as follows:

[0330] - Exploring offline (kV, T) by using simulations or by taking measurements of the system (or by using a hybrid approach) PMMA ,T Al )space

[0331] -Derivation of kV(T PMMA ,T Al )=argmax kV′ {CNRD(kV′,T PMMA ,T Al )}

[0332] If the equivalent thickness material used is PMMA, then it is possible to calculate kV(T PMMA,0) (using data extrapolation method) to derive the optimal voltage (in kV) value for the single energy exploration view.

[0333] Here, for simplicity, only the kV-space (p=kV) is optimized for fixed spectral filtering and fixed detector energy threshold. However, if a multi-valued parameter, such as p=(kV, filter, threshold), is optimized, the basic principle remains the same:

[0334] - Still exploring the search space (p,T PMMA ,T Al ),

[0335] - and then calculate p(T PMMA ,T Al )=argmax p′ {CNRD(p′,T PMMA ,T A1 )}

[0336] The calculation step 26 performs the calculation of the acquisition speed of the vertical scan along the height of the standing (or seated) patient and the calculation of the current modulation distribution along the height of the patient.

[0337] For a given voltage value or a given voltage profile, the current profile and vertical scan speed selection strategy is similar to the strategy used in patent application WO2021 / 094806 (hereby incorporated by reference), in summary:

[0338] - Calculate the exposure budget (the current value required to achieve the exposure target multiplied by the exposure time),

[0339] - maximize the vertical scan speed given the available tube current budget (constrained by the hardware specifications in terms of minimum and maximum tube power and minimum and maximum instantaneous current values),

[0340] - From this the corresponding current distribution is calculated.

[0341] Given a set of parameters The optimal voltage value (including thickness distribution) is used to achieve the target signal S T The product of the required current value and the exposure time (in mAs: milliampere-seconds) is

[0342]

[0343] The exposure time t is given by the highest current value that can be used for a given voltage value, taking into account tube power limitations and lower and upper current limits. The acquisition speed is selected (either as a free value or in a set of admissible system speeds) as the minimum speed among the calculated speeds along the thickness profile. Then, given this fixed acquisition speed, the current value is updated to match the target signal.

[0344] Whenever the current value drops below or exceeds the current limit, respectively, the voltage may be reduced or increased, respectively, in order to return it to the permissible value range until the voltage value itself reaches its lower and / or upper limits. Matching the target signal is preferred over maintaining the optimal voltage value, and this preference is due to the feedback loop from step 26 to step 23 (see Figure 1 and Figure 2 ) and be satisfied.

[0345] Once the optimal exposure parameters are selected, their distribution along the slot scan can be further adapted to the hardware constraints (e.g., in the slopes of the current and voltage profiles), if these constraints have not been taken into account in the previous steps. The exposure parameters are then formatted into a file readable by the system, and the image acquisition step 3 (see Figure 1 and Figure 2 ).

[0346] Figures 11 to 16 The effect of normalization step 4 is shown. The exact data normalization step 4 (see Figure 1 and Figure 2 ) may include additional air measurements (up to a factor of the current value) using the same exposure technique, or simulations, or a hybrid approach combining online image acquisition with simulations. It is sufficient to normalize the image acquisition by air measurements (also called "raw radiance"), but this normalization step 4 may also advantageously include an image processing algorithm in order to account for system variability. Once the normalization step 4 is performed, a standard image processing pipeline may be used.

[0347] Fig.11 An example of a normalization step within a radiological imaging method according to an embodiment of the present invention is shown, which shows a patient frontal non-normalized image. There is a patient frontal non-normalized image 41 .

[0348] Fig.12 An example of a normalization step within a radiographic imaging method according to an embodiment of the present invention is shown, which shows a patient front raw radiation image. There is a front raw radiation image 42, which is a front image of air without a patient.

[0349] Fig.13 An example of a normalization step within a radiographic imaging method according to an embodiment of the present invention is shown, which shows a patient front normalized image. There is a patient front normalized image 43 obtained by dividing the patient front unnormalized image 41 by the front raw radiation image 42.

[0350] Fig.14 An example of a normalization step within a radiological imaging method according to an embodiment of the present invention is shown, which shows a patient-side unnormalized image. There is a patient-side unnormalized image 44 .

[0351] Fig.15 An example of a normalization step within a radiographic imaging method according to an embodiment of the present invention is shown, which shows a patient side raw radiation image. There is a side raw radiation image 45, which is a side image of air without a patient.

[0352] Fig.16 An example of a normalization step within a radiographic imaging method according to an embodiment of the present invention is shown, which shows a patient side normalized image. There is a patient side normalized image 46 obtained by dividing the patient side unnormalized image 44 by the side raw radiation image 45.

[0353] Figures 17 to 39 Simulation results of a radiation imaging method according to an embodiment of the present invention will now be shown.

[0354] A simulated voxelized anthropomorphic phantom made of PMMA and Al was used. Thickness distributions were extracted in both frontal and side exploratory views and used to calculate exposure parameters.

[0355] The simulation situation is:

[0356] - Single energy exploration view, generating tube current modulation:

[0357] ○With fixed voltage,

[0358] ○With modulation voltage,

[0359] - Dual energy probing view (as in the present invention), resulting in tube current modulation with modulation voltage.

[0360] To conduct exposure quality assessment:

[0361] - Extract distributions of interest (e.g. Figure 1 and Figure 2 The signal distribution is thus the smoothed image detector signal along this distribution of interest, denoted S,

[0362] -The local deviation exponential distribution is calculated as

[0363] -The global deviation index value is where X(S) describes the central tendency of S along the distribution of interest, such as the mean M(S) or median m(S) following the IEC 62494-1 standard. The closer the deviation index is to zero, the better the exposure quality.

[0364] The simulation results will show:

[0365] - fixed voltage situations resulted in underexposed areas where bone dominated relative to PMMA (e.g. patient neck and patient legs),

[0366] - voltage modulation using only the PMMA thickness distribution brings the signal distribution closer to its target, but still misses the target in the thinner areas,

[0367] - Voltage modulation using both PMMA thickness distribution and Al thickness distribution produces a flatter signal distribution, where the deviation index is closer to zero.

[0368] Fig.17 An example of a single energy probing view with a signal-to-PMMA mapping obtained only by a radiographic method not according to an embodiment of the present invention is shown.

[0369] Curves 301 and 302 show the thickness distribution tp along the distance d from the top of the patient (the vertex of the head), which corresponds to the patient's height. Curve 301 shows the frontal soft tissue thickness distribution along the patient's height. Curve 302 shows the lateral soft tissue thickness distribution along the patient's height.

[0370] Fig.18 An example of a multi-energy probing view with signal-to-PMMA and signal-to-AI mappings obtained by a radiological imaging method according to an embodiment of the present invention is shown.

[0371] Curves 311, 312, 313 and 314 show the thickness distribution tp along the distance d from the top of the patient (the vertex of the head), which is also the patient height (starting from the top of the patient). Curve 311 shows the front soft tissue thickness distribution along the patient height. Curve 312 shows the lateral soft tissue thickness distribution along the patient height. Curve 313 shows the front bone thickness distribution along the patient height. Curve 314 shows the lateral bone thickness distribution along the patient height.

[0372] Fig.19 An example of a simulation of the expected tube power distribution with front and side single energy probing views, with current modulation but without voltage modulation, not according to an embodiment of the present invention is shown.The vertical scanning speed is 45 mm per second.

[0373] Curve 321 shows the frontal tube power distribution P along the distance d from the top of the patient (the vertex of the head). Curve 322 shows the lateral tube power distribution P along the distance d from the top of the patient (the vertex of the head). Horizontal line 320 shows the tube power limit that cannot be exceeded without saturation. The maximum tube power limit is 42kW.

[0374] Fig. 20 Shown corresponding to Fig.19 Example of current modulation profile. The vertical scanning speed is 45 mm per second.

[0375] Curve 331 shows the frontal tube current distribution I along a distance d from the top of the patient (the vertex of the head). Curve 332 shows the lateral tube current distribution I along a distance d from the top of the patient (the vertex of the head). Horizontal line 330 shows the tube current limit that cannot be exceeded without saturation. The available tube current ranges from a minimum of 10 mA to a maximum of 400 mA.

[0376] Fig.21 Shown corresponding to Fig.19 The vertical scanning speed is 45 mm per second.

[0377] Horizontal line 340 shows a fixed tube voltage that remains constant along the patient height. Available tube voltages range from a minimum of 50 kV to a maximum of 130 kV.

[0378] Fig. 22 Shown corresponding to Fig.19 Example of frontal bone localization distribution along the patient's height. The vertical scanning speed is 45 mm per second.

[0379] Curve 350 shows the frontal bone positioning along the distance d from the top of the patient (the vertex of the head) and along the width w of the patient.

[0380] The gray areas correspond to distribution points where the lower and / or upper limits of the system are reached and correspond to Fig. 22 and Fig.23 Gray linear frontal regions 351 and side regions 361 in the frontal and side images of FIG. 3 (bone location distributions 350 and 360 are shown as dashed lines). Many large frontal regions 351 can be seen here.

[0381] Fig.23 Shown corresponding to Fig.19 Example of lateral bone localization distribution along the contour of the patient of interest. The vertical scanning speed is 45 mm per second.

[0382] Curve 360 ​​shows lateral bone positioning along a distance d from the top of the patient (the vertex of the head) and along the thickness th of the patient.

[0383] The gray areas correspond to distribution points where the lower and / or upper limits of the system are reached and correspond to Fig. 22 and Fig.23 Gray linear frontal regions 351 and side regions 361 in the frontal and side images of FIG. 3 (bone location distributions 350 and 360 are shown as dashed lines). Many large side regions 361 can be seen here.

[0384] Fig.24An example of a simulation of the expected tube power distribution with front and side single energy probing views, with both current and voltage modulation, is shown, not in accordance with an embodiment of the present invention.The vertical scanning speed is 45 mm per second.

[0385] Curve 371 shows the frontal tube power distribution P along the distance d from the top of the patient (the vertex of the head). Curve 372 shows the lateral tube power distribution P along the distance d from the top of the patient (the vertex of the head). Horizontal line 370 shows the tube power limit that cannot be exceeded without saturation. The maximum tube power limit is 42kW.

[0386] Fig.25 Shown corresponding to Fig.24 Example of current modulation profile. The vertical scanning speed is 45 mm per second.

[0387] Curve 381 shows the frontal tube current distribution I along a distance d from the top of the patient (the vertex of the head). Curve 382 shows the lateral tube current distribution I along a distance d from the top of the patient (the vertex of the head). Horizontal line 380 shows the tube current limit that cannot be exceeded without saturation. The available tube current ranges from a minimum of 10 mA to a maximum of 400 mA.

[0388] Fig.26 Shown corresponding to Fig.24 An example of a voltage modulation profile of . The vertical scanning speed is 45 mm per second.

[0389] Curve 391 shows the frontal tube voltage distribution V along the distance d from the top of the patient (the vertex of the head). Curve 392 shows the lateral tube voltage distribution V along the distance d from the top of the patient (the vertex of the head). Horizontal line 390 shows the tube voltage limit that cannot be exceeded without saturation. Available tube voltages range from a minimum of 50 kV to a maximum of 130 kV.

[0390] Fig. 27 Shown corresponding to Fig.24 Example of frontal bone localization distribution along the contour of the patient of interest. The vertical scanning speed is 45 mm per second.

[0391] Curve 400 shows frontal bone positioning along a distance d from the top of the patient (the vertex of the head) and along the width w of the patient.

[0392] The gray areas correspond to distribution points where the lower and / or upper limits of the system are reached and correspond to Fig.28 The gray linear lateral region 411 in the lateral image of FIG. 4 (bone location distributions 400 and 410 are shown as dashed lines). The frontal region is not visible here.

[0393] Fig.28 Shown corresponding to Fig.24 Example of lateral bone localization distribution along the contour of the patient of interest. The vertical scanning speed is 45 mm per second.

[0394] Curve 410 shows lateral bone positioning along a distance d from the top of the patient (the vertex of the head) and along the thickness th of the patient.

[0395] The gray areas correspond to distribution points where the lower and / or upper limits of the system are reached and correspond to Fig.28 4. Here, there is a single but slightly larger lateral region 411 (bone location distributions 400 and 410 are shown as dashed lines) in the lateral image of FIG.

[0396] Fig.29 An example of a simulation of the expected tube power distribution with front and side single energy probing views according to an embodiment of the present invention is shown, with both current modulation and voltage modulation.The vertical scanning speed is 45 mm per second.

[0397] Curve 421 shows the frontal tube power distribution P along the distance d from the top of the patient (the vertex of the head). Curve 422 shows the lateral tube power distribution P along the distance d from the top of the patient (the vertex of the head). Horizontal line 420 shows the tube power limit that cannot be exceeded without saturation. The maximum tube power limit is 42 kW (kW = kilowatt).

[0398] Fig.30 Shown corresponding to Fig.29 The vertical scanning speed is 45 mm (mm = millimeter) per second.

[0399] Curve 431 shows the frontal tube current distribution I along the distance d from the top of the patient (the vertex of the head). Curve 432 shows the lateral tube current distribution I along the distance d from the top of the patient (the vertex of the head). Horizontal line 430 shows the tube current limit that cannot be exceeded without saturation. The available tube current ranges from a minimum of 10 mA to a maximum of 400 mA.

[0400] Fig.31 Shown corresponding to Fig.29 An example of a voltage modulation profile of . The vertical scanning speed is 45 mm per second.

[0401] Curve 441 shows the frontal tube voltage distribution V along the distance d from the top of the patient (the vertex of the head). Curve 442 shows the lateral tube voltage distribution V along the distance d from the top of the patient (the vertex of the head). Horizontal line 440 shows the tube voltage limit that cannot be exceeded without saturation. Available tube voltages range from a minimum of 50 kV to a maximum of 130 kV.

[0402] Fig.32 Shown corresponding to Fig.29 Example of frontal bone localization distribution along the contour of the patient of interest. The vertical scanning speed is 45 mm per second.

[0403] Curve 450 shows the frontal bone positioning along the distance d from the top of the patient (the vertex of the head) and along the width w of the patient.

[0404] The gray areas correspond to distribution points where the lower and / or upper limits of the system are reached and correspond to Fig.33 The gray linear lateral region 461 in the lateral image of FIG. 4 (bone location distributions 450 and 460 are shown as dashed lines). The frontal region is not visible here.

[0405] Fig.33 Shown corresponding to Fig.29 Example of lateral bone localization distribution along the contour of the patient of interest. The vertical scanning speed is 45 mm per second.

[0406] Curve 460 shows lateral bone positioning along a distance d from the top of the patient (the vertex of the head) and along the thickness th of the patient.

[0407] The gray areas correspond to distribution points where the lower and / or upper limits of the system are reached and correspond to Fig.33 4. A gray linear lateral region 461 in the lateral image of FIG. 4 (bone location distributions 450 and 460 are shown as dashed lines). Here, there is a single and relatively narrow lateral region 461.

[0408] Fig.34 An example of a frontal bone location distribution along the contour of a patient of interest in a modulated image obtained by simulation is shown. Frontal bone location distribution 470 along patient height d and along patient width w.

[0409] Fig.35 An example of lateral bone location distribution along the contour of a patient of interest in a modulated image obtained by simulation is shown: Lateral bone location distribution 480 along patient height d and along patient thickness th.

[0410] Fig.36 An example of a simulation showing the frontal signal distribution along the contour of a patient of interest is shown. The frontal signal distribution in number of counts nc along the patient height d is shown by the following curve, M is the mean and m is the median:

[0411] -To reach the target of 500,

[0412] - curve 501 for a single energy probing view with current modulation and without voltage modulation, which gives the worst results,

[0413] - a curve 502 for a single energy probing view with current modulation and with voltage modulation, which gives an intermediate result,

[0414] - Curve 503 for a multi-energy (here dual-energy) probing view with current modulation and with voltage modulation, which gives the best results.

[0415] Fig.37 An example of a simulation of the frontal deviation index distribution along the contour of a patient of interest is shown.

[0416] The distribution of the frontal deviation index, expressed as the deviation index DI, along the patient height d is shown by the following curve, M being the mean value and m being the median value:

[0417] -To achieve the target of 510,

[0418] - curve 514 corresponding to a deviation of + or -1 respectively from target 500,

[0419] - curve 511 for a single energy probing view with current modulation and without voltage modulation, which gives the worst results,

[0420] - a curve 512 for a single energy probing view with current modulation and with voltage modulation, which gives an intermediate result,

[0421] - Curve 513 for a multi-energy (here dual-energy) probing view with current modulation and with voltage modulation, which gives the best results.

[0422] Fig.38 An example of a simulation of the lateral signal distribution along the contour of a patient of interest is shown.

[0423] The distribution of the lateral signal in number of counts nc along the patient height d (starting from the top of the patient) is shown by the following curve, with M being the mean and m being the median:

[0424] -To achieve the goal of 520,

[0425] - curve 521 for a single energy probing view with current modulation and without voltage modulation, which gives the worst results,

[0426] - a curve 522 for a single energy probing view with current modulation and with voltage modulation, which gives an intermediate result,

[0427] - Curve 523 for a multi-energy (here dual-energy) probing view with current modulation and with voltage modulation, which gives the best results.

[0428] Fig.39 An example of a simulation of the distribution of the side deviation index along the contour of a patient of interest is shown.

[0429] The distribution of the lateral deviation index, expressed as the deviation index DI, along the patient height d (starting from the top of the patient) is shown by the following curve, with M being the mean value and m being the median value:

[0430] -To achieve the target of 530,

[0431] - curve 534 corresponding to a deviation of + or -1 respectively from the target 530,

[0432] - curve 531 for a single energy probing view with current modulation and without voltage modulation, which gives the worst results,

[0433] - a curve 532 for a single energy probing view with current modulation and with voltage modulation, which gives an intermediate result,

[0434] - Curve 533 for a multi-energy (here dual-energy) probing view with current modulation and with voltage modulation, which gives the best results.

[0435] Figures 40 to 45 Experimental results of a radiation imaging method according to an embodiment of the present invention will now be shown.

[0436] Fig.40 An example of the structure of an imaging device for implementing a radiation imaging method according to an embodiment of the present invention is shown. Fig.40 The patient height is also orthogonal to Fig.40 The vertical scanning direction is the patient height scanning direction, so the scanning direction is along the patient height of a standing patient.

[0437] There is a phantom 110 comprising a PMMA portion 111 and an Al portion 112 , which is located on an imaging area 107 of an imaging device or apparatus 109 .

[0438] The frontal transmit and receive line includes a frontal tube 101 which emits an X-ray frontal beam 105 which passes through a phantom 110 and reaches a frontal detector 102 .

[0439] The side transmit and receive line includes a side tube 103 that transmits a side beam 106 of X-rays that passes through a phantom 110 and reaches a side detector 104 .

[0440] To avoid cross scatter in the intersection region 108, a mechanical correction with vertical gaps between the front and side transmit and receive lines and / or a software cross scatter correction between the front and side transmit and receive lines may be used as previously mentioned.

[0441] Fig.41An example of a region of a detector used for average value calculation during implementation of a radiographic method according to an embodiment of the present invention is shown. Region 120 is a region used for average signal value calculation.

[0442] The process of obtaining the experimental results is as follows:

[0443] - Combine the known PMMA thickness with the known Al-1100 thickness,

[0444] - Obtain equivalent PMMA thickness from single energy probing views,

[0445] - obtaining a single energy image using the values ​​of voltage, current and vertical scanning speed given by the equivalent PMMA thickness (for the single energy probing view),

[0446] In this case, the signal-to-thickness mapping maps the total energy probe view to PMMA thickness, and this mapping is then used online,

[0447] - obtaining a single energy image using the values ​​of voltage, current and vertical scanning speed given by the (PMMA, Al) thickness pair (for the dual energy probing view),

[0448] -Measure the average signal value in the central part of the image, denoted as M(S), such as Fig.41 As shown,

[0449] - Calculate the deviation index between this value and the target signal value; the deviation index is defined as:

[0450]

[0451] Where S T is the target detector signal value; the closer the deviation index is to zero, the better the exposure quality.

[0452] The experimental results illustrate the high interest of the dual energy probing view by showing that:

[0453] - The further away from the setup the model is from the single energy exploration view (primarily PMMA), the further the deviation index is from zero,

[0454] - The knowledge of the (PMMA, Al) thickness from the phantom based on the dual energy probing view stabilizes the deviation index around zero regardless of the test setup.

[0455] Fig.42 Showing an example of optimal kV mapping during a radiological imaging method not according to an embodiment of the present invention, the exploration view is mono-energy.

[0456] For each setting, the optimal voltage (kV) value is calculated from the equivalent PMMA thickness vector based on the single energy using the CNRD-based kV map. The grayscale of the point 601 in the grid corresponds to the value of the voltage on the right vertical voltage bar. Various couplings of Al thickness th1 and PMMA thickness th2 are expected. Lower voltages are used for lower PMMA thicknesses, and higher voltages are used for higher PMMA thicknesses.

[0457] Fig.43 Showing an example of optimal kV mapping during a radiological imaging method according to an embodiment of the present invention, the exploration view is multi-energy.

[0458] For each setting, the optimal voltage (kV) value is calculated from the (PMMA, Al) thickness vector pair based on dual energy using the CNRD-based kV map. The grayscale of the point 602 in the grid corresponds to the value of the voltage on the right vertical voltage bar. Various couplings of Al thickness th1 and PMMA thickness th2 are expected. Lower voltages are used for lower PMMA thicknesses, and also for lower Al thicknesses to a certain extent, and higher voltages are used for higher PMMA thicknesses, and also for higher Al thicknesses to a certain extent.

[0459] Fig.44 An example of a deviation index graph showing optimal kV mapping during a radiological imaging method not according to an embodiment of the present invention, the exploration view being mono-energy.

[0460] The small deviation index is represented by a circle, the intermediate deviation index is represented by a square, and the large deviation index is represented by a triangle. The grayscale of the point 603 in the grid corresponds to the value of the deviation index on the vertical deviation index bar on the right. Various couplings of Al thickness th1 and PMMA thickness th2 are expected. Lower deviation index values ​​are obtained for higher PMMA thicknesses and for lower Al thicknesses, and higher deviation index values ​​are obtained for lower PMMA thicknesses and for higher Al thicknesses. Some points 603 are circular, but most of them are squares or triangles, which is not optimal. In the case of understanding the equivalent PMMA thickness only from a single energy exploration view, the deviation index will be wrong whenever the contribution of Al is dominant relative to PMMA (squares and triangles).

[0461] The non-monotonic results at high Al thicknesses around 15 cm to 20 cm PMMA can be explained by the variable choice of kV values.

[0462] Fig.45 An example of a deviation index graph showing optimal kV mapping during a radiological imaging method according to an embodiment of the present invention, the exploration view being multi-energy.

[0463] Small deviation indices are represented by circles, intermediate deviation indices by squares and large deviation indices by triangles. The grayscale of a point 604 in the grid corresponds to the value of the deviation index on the vertical deviation index bar on the right. Various couplings of Al thickness th1 and PMMA thickness th2 are expected. Small and therefore good deviation index values ​​are obtained for both high and low PMMA thicknesses and for both high and low Al thicknesses. All points 604 are circles, which is optimal. Fig.45 The knowledge of the (Al, PMMA) thickness from the dual energy probing view provides the bias index ratio Fig.44 The deviation index is closer to zero and thus the exposure parameters are better.

[0464] The invention has been described with reference to preferred embodiments. However, many variations are possible within the scope of the invention.

Claims

1. A radiographic imaging method, comprising: Two radiation sources (101, 103) with imaging directions orthogonal to each other, a front radiation source (101) and a side radiation source (103), wherein the radiation sources slide vertically so as to perform vertical scanning on a standing patient along a vertical scanning direction, Two radiation detectors (102, 104) respectively associated with the two radiation sources (101, 103), a front radiation detector (102) and a side radiation detector (104), the radiation detectors vertically sliding to vertically scan a standing patient along the vertical scanning direction, at least the front radiation detectors (102, 104) being multi-energy counting detectors, The radiation method comprises at least one operating mode, in which: (1) a frontal multi-energy exploration view is obtained by performing a preliminary vertical scan on a standing patient along the vertical scanning direction by the frontal radiation source (101) and the frontal radiation detector (102), so that the frontal radiation detector (102) at least provides: a first frontal exploration view corresponding to a first portion of energy received by the frontal radiation detector (102) and below a first given energy threshold, referred to as a low energy frontal exploration view, a second frontal exploration view corresponding to a second portion of the energy received by the frontal radiation detector (102) and above a second given energy threshold, referred to as a high energy frontal exploration view, The first frontal exploratory view and the second frontal exploratory view are combined and processed (20) to evaluate: ○At least the patient's bone thickness (22), ○ At least the patient's soft tissue thickness (22), o patient-specific bone positioning at different imaging positions along said vertical scanning direction (21), (3) a frontal image is obtained by vertically scanning a standing patient along the vertical scanning direction by the frontal radiation source (101) and the frontal radiation detector (102), wherein: o modulating the intensity of the driving current of at least the front radiation source (101) along the vertical scanning direction according to the patient's bone thickness, according to the patient's soft tissue thickness and according to the patient's specific bone positioning at different imaging positions along the vertical scanning direction, and preferably also modulating the intensity of the driving voltage of the front radiation source (101) along the vertical scanning direction according to the patient's bone thickness, according to the patient's soft tissue thickness and according to the patient's specific bone positioning at different imaging positions along the vertical scanning direction, o Automatically modulating the intensity of the driving current of the front radiation source (101) without modulating the intensity of the voltage of the front radiation source (101) so as to improve the compromise between: ■ the total radiation dose received by the patient during said vertical scan, ■ and for the en face image, the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction, o or simultaneously, preferably synchronously and automatically, the driving current intensity modulation and voltage intensity modulation of the front radiation source (101) are performed to improve the compromise between: ■ the total radiation dose received by the patient during the vertical scan, ■ and, for the en face image, the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction.

2. A radiographic method, comprising: Two radiation sources (101, 103) with imaging directions orthogonal to each other, a front radiation source (101) and a side radiation source (103), wherein the radiation sources slide vertically so as to perform vertical scanning on a standing patient along a vertical scanning direction, Two radiation detectors (102, 104) respectively associated with the two radiation sources (101, 103), a front radiation detector (102) and a side radiation detector (104), the radiation detectors vertically sliding to vertically scan a standing patient along the vertical scanning direction, at least the side radiation detector (104) being a multi-energy counting detector, The radiation method comprises at least one operating mode, in which: (1) A lateral multi-energy exploration view is obtained by performing a preliminary vertical scan on a standing patient along the vertical scanning direction by the lateral radiation source (103) and the lateral radiation detector (104), so that the lateral radiation detector (104) at least provides: a first side exploration view corresponding to a first portion of energy received by the side radiation detector (104) and below a first given energy threshold, referred to as a low energy side exploration view, a second side exploration view corresponding to a second portion of energy received by the side radiation detector (104) and above a second given energy threshold, referred to as a high energy side exploration view, The first lateral exploratory view and the second lateral exploratory view are combined and processed (20) to evaluate: ○At least the patient's bone thickness (22), ○ At least the patient's soft tissue thickness (22), o patient-specific bone positioning at different imaging positions along said vertical scanning direction (21), (3) A lateral image is obtained by vertically scanning a standing patient along the vertical scanning direction by the lateral radiation source (103) and the lateral radiation detector (104), wherein: o modulating the intensity of the driving current of at least the side radiation source (103) along the vertical scanning direction according to the patient's bone thickness, according to the patient's soft tissue thickness and according to the patient's specific bone positioning at different imaging positions along the vertical scanning direction, and preferably also modulating the intensity of the driving voltage of the side radiation source (103) along the vertical scanning direction according to the patient's bone thickness, according to the patient's soft tissue thickness and according to the patient's specific bone positioning at different imaging positions along the vertical scanning direction, o Automatically modulate the intensity of the driving current of the side radiation source (103) without modulating the intensity of the voltage of the side radiation source (103) so as to improve the compromise between: ■ the total radiation dose received by the patient during said vertical scan, ■ and for the lateral image, the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction, o or simultaneously, preferably synchronously and automatically, the driving current intensity modulation and voltage intensity modulation of the side radiation source (103) are performed to improve the compromise between: ■ the total radiation dose received by the patient during the vertical scan, ■ and, for the lateral image, the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction.

3. A radiographic imaging method, comprising: Two radiation sources (101, 103) with imaging directions orthogonal to each other, a front radiation source (101) and a side radiation source (103), wherein the radiation sources slide vertically so as to perform vertical scanning on a standing patient along a vertical scanning direction, Two radiation detectors (102, 104) respectively associated with the two radiation sources (101, 103), a front radiation detector (102) and a side radiation detector (104), the radiation detectors vertically sliding to vertically scan a standing patient along the vertical scanning direction, the two radiation detectors (102, 104) respectively being two multi-energy counting detectors, The radiation method comprises at least one operating mode, in which: (1) a front multi-energy exploration view and a side multi-energy exploration view are obtained by performing a preliminary vertical scan on a standing patient along the vertical scanning direction by the front radiation source and the side radiation source (101, 103) and by the front radiation detector and the side radiation detector (102, 104), so that the front radiation detector and the side radiation detector (102, 104) at least give: a first frontal exploration view corresponding to a first portion of energy received by the frontal radiation detector (102) and below a first given energy threshold, referred to as a low energy frontal exploration view, a second frontal exploration view corresponding to a second portion of the energy received by the frontal radiation detector (102) and above a second given energy threshold, referred to as a high energy frontal exploration view, a first side exploration view corresponding to a first portion of energy received by the side radiation detector (104) and below a first given energy threshold, referred to as a low energy side exploration view, a second side exploration view corresponding to a second portion of energy received by the side radiation detector (104) and above a second given energy threshold, referred to as a high energy side exploration view, The first front exploratory view and the first side exploratory view and the second front exploratory view and the second side exploratory view are combined and processed (20) to evaluate: ○At least the patient's bone thickness (22), ○ At least the patient's soft tissue thickness (22), o patient-specific bone positioning at different imaging positions along said vertical scanning direction (21), (3) a front image is obtained by vertically scanning a standing patient by the front radiation source (101) and by the front radiation detector (102) along the vertical scanning direction, and a side image is obtained by vertically scanning a standing patient by the side radiation source (103) and by the side radiation detector (104) along the vertical scanning direction, and both the front image and the side image are obtained during the same vertical scanning, wherein: o modulating the drive current intensity of both the front radiation source and the side radiation source (101, 103) along the vertical scanning direction according to the patient's bone thickness, according to the patient's soft tissue thickness and according to the patient's specific bone positioning at different imaging positions along the vertical scanning direction, and preferably also modulating the driving voltage intensity of both the front radiation source and the side radiation source (101, 103) along the vertical scanning direction according to the patient's bone thickness, according to the patient's soft tissue thickness and according to the patient's specific bone positioning at different imaging positions along the vertical scanning direction, o At the same time, preferably synchronously and automatically, the intensity modulation of the driving current of the front radiation source (101) is performed without the voltage intensity modulation of the front radiation source (101), and the intensity modulation of the driving current of the side radiation source (103) is performed without the voltage intensity modulation of the side radiation source (103), so as to improve the compromise between: ■ the total radiation dose received by the patient during said vertical scan, ■ and, for the frontal image and the lateral image, the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction, o or simultaneously, preferably synchronously and automatically, the driving current intensity modulation and voltage intensity modulation of the front radiation source (101), and simultaneously, preferably synchronously and automatically, the driving current intensity modulation and voltage intensity modulation of the side radiation source (103), so as to improve the compromise between: ■ the total radiation dose received by the patient during the vertical scan, ■ And the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction for the frontal image and the lateral image.

4. The radiographic method according to any one of the preceding claims, characterized in that: (1) The frontal multi-energy exploration view is obtained by performing a single preliminary vertical scan on a standing patient by the frontal radiation source (101) and the frontal radiation detector (102) along the vertical scanning direction, so that the frontal radiation detector (102) at least gives: ○The first frontal exploratory view, ○The second frontal exploratory view, (1) The lateral multi-energy exploration view is obtained by performing a single preliminary vertical scan on a standing patient along the vertical scanning direction by the lateral radiation source (103) and the lateral radiation detector (104), so that the lateral radiation detector (104) at least provides: o The first side profile view, ○The second side exploratory view, Both the frontal multi-energy probing view and the lateral multi-energy probing view are obtained during the same single preliminary vertical scan.

5. The radiographic method according to any one of the preceding claims, characterized in that: (3) the frontal image is obtained by performing a single vertical scan on a standing patient along the vertical scanning direction by the frontal radiation source (101) and the frontal radiation detector (102), (3) the side image is obtained by performing a single vertical scan of a standing patient along the vertical scanning direction by the side radiation source (103) and the side radiation detector (104), Both the frontal image and the lateral image are obtained during the same single vertical scan.

6. The radiographic method according to any one of the preceding claims, characterized in that The first given energy threshold is equal to or less than the second given energy threshold, and preferably equal to the second given energy threshold.

7. The radiographic method according to claim 6, characterized in that: The first given energy threshold is equal to the second given energy threshold, The front multi-energy probing view and / or the side multi-energy probing view are obtained (1), so that the front radiation detector and / or the side radiation detector (102, 104) first gives: ○The first frontal exploratory view, o a third frontal exploration view, corresponding to the total energy received by the frontal radiation detector (102), referred to as the total energy frontal exploration view, ■ obtaining the second frontal exploratory view by subtracting the first frontal exploratory view from the third frontal exploratory view, ○ and / or said first lateral exploration view, o and / or a third side profile view corresponding to the total energy received by the side radiation detector (104), referred to as a total energy side profile view, ■ The second lateral exploratory view is obtained by subtracting the first lateral exploratory view from the third lateral exploratory view.

8. The radiographic method according to any one of the preceding claims, characterized in that: combining and processing the first frontal exploratory view and / or the first lateral exploratory view and the second frontal exploratory view and / or the second lateral exploratory view to evaluate (22) a distribution of bone thickness of the patient along the vertical scanning direction, and / or combining and processing the first frontal exploratory view and / or the first lateral exploratory view and the second frontal exploratory view and / or the second lateral exploratory view so as to evaluate (22) the patient's soft tissue thickness distribution along the vertical scanning direction, The frontal image is obtained by vertically scanning a standing patient along the vertical scanning direction by the frontal radiation source (101) and the frontal radiation detector (102), wherein: ○ According to the patient's bone thickness distribution and / or the patient's soft tissue thickness distribution along the vertical scanning direction, modulating the driving current intensity of at least the front radiation source (101) along the vertical scanning direction, and preferably, the driving voltage intensity of the front radiation source (101) is modulated along the vertical scanning direction according to the patient's bone thickness distribution and the patient's soft tissue thickness distribution along the vertical scanning direction, The side image is obtained by vertically scanning a standing patient along the vertical scanning direction by the side radiation source (103) and by the side radiation detector (104), wherein: ○ According to the patient's bone thickness distribution and / or the patient's soft tissue thickness distribution along the vertical scanning direction, modulating the driving current intensity of at least the side radiation source (103) along the vertical scanning direction, ○ And preferably, the driving voltage intensity of the side radiation source (103) is modulated along the vertical scanning direction according to the patient's bone thickness distribution and the patient's soft tissue thickness distribution along the vertical scanning direction, Both the frontal image and the lateral image are obtained during the same vertical scan.

9. The radiographic method according to any one of the preceding claims, characterized in that: o Automatically modulating the intensity of the driving current of the front radiation source and / or the side radiation source (101, 103) without modulating the voltage intensity of the front radiation source and / or the side radiation source (101, 103) so as to improve the compromise between: ■ reducing the total radiation dose received by the patient during the vertical scan, and for the frontal image and / or the lateral image, for all or part of the patient thickness along the vertical scanning direction, not reducing the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction at a given contrast threshold, o or simultaneously, preferably synchronously and automatically, both the driving current intensity modulation and the voltage intensity modulation of the front radiation source and / or the side radiation source (101, 103) are performed in order to improve the compromise between: ■ reducing the total radiation dose received by the patient during the vertical scan, ■And for the frontal image and / or the lateral image, for all or part of the patient thickness along the vertical scanning direction, the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction is increased relative to the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction with the same total radiation dose but without any drive current intensity modulation or any drive voltage intensity modulation.

10. The radiographic method according to any one of the preceding claims, characterized in that: o Automatically modulating the intensity of the driving current of the front radiation source and / or the side radiation source (101, 103) without modulating the voltage intensity of the front radiation source and / or the side radiation source (101, 103) so as to improve the compromise between: ■ reducing the total radiation dose received by the patient during the vertical scan, and for the frontal image and / or the lateral image, for all or part of the patient thickness along the vertical scanning direction, improving the contrast-to-noise ratio or the ratio between the contrast-to-noise ratio and the square root of the total radiation dose at different imaging positions along the vertical scanning direction relative to the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction with the same total radiation dose but without any drive current intensity modulation, o or simultaneously, preferably synchronously and automatically, both the driving current intensity modulation and the voltage intensity modulation of the front radiation source and / or the side radiation source (101, 103) are performed in order to improve the compromise between: ■ reducing the total radiation dose received by the patient during the vertical scan, ■And for the frontal image and / or the lateral image, for all or part of the patient thickness along the vertical scanning direction, the contrast-to-noise ratio of the identified specific bone location at different imaging positions along the vertical scanning direction or the ratio between the contrast-to-noise ratio and the square root of the total radiation dose is improved relative to the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction with the same total radiation dose but without any drive current intensity modulation or any drive voltage intensity modulation.

11. The radiographic method according to any one of the preceding claims, characterized in that: Using at least 2 energy bins, or using at least 3 energy bins, or using at least 6 energy bins to perform (1) the frontal multi-energy exploration view acquisition, ○ and / or up to 20 energy bins, or up to 15 energy bins, or up to 10 energy bins, and / or using at least 2 energy bins or using at least 3 energy bins or using at least 6 energy bins to perform (1) the side multi-energy exploration view acquisition, ○ and / or up to 20 energy bins, or up to 15 energy bins, or up to 10 energy bins.

12. The radiographic method according to any one of the preceding claims, characterized in that: processing the first front side exploration view and the second front side exploration view as a multi-material decomposition having at least two vertical distributions of material thickness, ○ Preferably, a bi-material decomposition between Al and PMMA, or a bi-material decomposition between HA and H2O, and / or processing the first side exploration view and the second side exploration view as a multi-material decomposition with at least two material thickness vertical vectors, ○ Preferably, a bi-material decomposition between Al and PMMA, or a bi-material decomposition between HA and H2O.

13. The radiographic method according to any one of the preceding claims, characterized in that: For each of the radiation detectors (102, 104): o The radiation detector pixel size is in the range of 50 μm to 250 μm, or in the range of 80 μm to 150 μm, or is about 100 μm, ○ and / or the total height of the radiation detector is in the range of 0.1 cm to 1.2 cm, or 0.2 cm to 1.0 cm, or 0.3 cm to 0.7 cm, o and / or the total width of the radiation detector is in the range of 10 cm to 80 cm, or 20 cm to 70 cm, or 30 cm to 60 cm, ○ And / or the radiation detector can operate in a time delay and sum mode.

14. The radiographic method according to any one of the preceding claims, characterized in that The identified specific skeletal location includes the patient's spine, preferably the patient's spine.

15. The radiographic method according to any one of the preceding claims, characterized in that Both the driving current intensity modulation and the voltage intensity modulation of the front radiation source and / or the side radiation source (101, 103) are also performed so as to achieve a certain signal-to-noise ratio value, which, for the front image and / or for the side image, is constant and common for most of the imaging positions along the vertical scanning direction, preferably for all the imaging positions along the vertical scanning direction, but can take two different values ​​for the front image and for the side image, respectively.

16. The radiological imaging method according to claim 15, characterized in that: For each of the en face image and / or the lateral image, the signal to noise ratio value is constant and predetermined for each different patient organ to be imaged.

17. The radiological imaging method according to claim 15 or 16, characterized in that: for a frontal image of the patient's spine, said standard signal-to-noise ratio value corresponds to a number of X-ray photons received per detector pixel comprised between 50 and 70, said radiographic imaging method operator having a probability, preferably via manual command, of deviating from this standard value by at least -25% or +100%, more preferably by at least -50% or +200%, And / or for a lateral image of the patient's spine, the standard signal-to-noise ratio value corresponds to a number of X-ray photons received by each detector pixel comprised between 20 and 40, and the operator of the radiographic imaging method preferably has the possibility of deviating from this standard value by at least -25% or +100%, more preferably by at least -50% or +200%, via manual command.

18. The radiographic method according to any one of the preceding claims, characterized in that The front image and / or the side image are normalized by homogenizing the original radiation after undergoing at least the local image contrast improvement so as to eliminate image artifacts from the drive current intensity modulation and the voltage intensity modulation, and preferably wherein the front image and / or the side image undergo a contrast enhancement step after having been normalized.

19. The radiographic method according to any one of the preceding claims, characterized in that The identified specific bone location excludes metal parts, if any, such as metal prostheses of skeletal parts of the patient's body or metal protectors placed on the patient's body prior to performing the radiographic method.

20. The radiographic method according to any one of the preceding claims, characterized in that: Modulate both the current and voltage: o Increase both current and voltage intensity for greater patient thickness, o Reduce both current and voltage intensity for smaller patient thicknesses, ○The rate of change of current intensity is slower than the rate of change of voltage intensity.

21. The radiographic method according to any one of the preceding claims, characterized in that The current intensity modulation is maximized in order to also maximize the vertical scanning speed to a constant value.

22. The radiographic method according to any one of the preceding claims, characterized in that The operating mode can be switched on or off manually by an operator of the radiographic method.

23. The radiographic method according to any one of the preceding claims, characterized in that The operating mode is dedicated for vertical scanning of large and / or obese patients, and / or wherein the operating mode is dedicated for vertical scanning of pediatric patients.

24. The radiographic method according to any one of the preceding claims, characterized in that The current intensity modulation rate does not exceed a predetermined threshold of 5 mA per millisecond, or does not exceed a predetermined threshold of 2 mA per millisecond, or does not exceed a predetermined threshold of 1 mA per millisecond.

25. The radiographic method according to any one of the preceding claims, characterized in that The current intensity modulation is at least in the range of 20 mA to 300 mA, and preferably in the range of 10 mA to 400 mA.

26. The radiographic method according to any one of the preceding claims, characterized in that The voltage intensity modulation is at least in the range of 60 kV to 100 kV, and preferably 50 kV to 130 kV.

27. The radiological imaging method according to any one of the preceding claims, characterized in that The vertical scanning speed value is at least in the range of 8 cm / sec to 20 cm / sec, and preferably in the range of 0.4 cm / sec to 35 cm / sec.

28. The radiographic method according to any one of the preceding claims, characterized in that Before obtaining each of the frontal image and the side image, (1) each of the frontal exploratory views and / or the side exploratory views is obtained by performing a preliminary vertical scan on a standing patient along a vertical scanning direction with a total radiation dose reduced compared to each of the frontal image and the side image, and preferably wherein the reduced total radiation is less than 10% of the total radiation dose, and more preferably less than 5% of the total radiation dose.

29. The radiographic method according to any one of the preceding claims, characterized in that The pixels in the exploration view are preferably grouped together in regions of NxN pixels, more preferably in regions in the range of 2x2 pixels to 10x10 pixels to obtain an imaging region.

30. The radiological imaging method according to any one of the preceding claims, characterized in that The image or the imaging region is processed to identify salient points (60) which are in turn used to calculate (22) the thickness distribution and identify (21) the specific bone location along the vertical scanning direction of a standing patient.

31. The radiographic method according to any one of the preceding claims, characterized in that The image or the imaging region is processed by a neural network to calculate (22) the thickness distribution and identify (21) the specific bone location along the vertical scanning direction of a standing patient.

32. A radiographic method according to any one of the preceding claims, characterized in that The two radiation sources (101, 103) slide vertically so as to vertically scan the pelvis or spine or the whole body of a standing patient along a vertical scanning direction.

33. A radiological imaging method according to any one of the preceding claims, characterized in that The two radiation detectors (102, 104) are associated with the two radiation sources (101, 103), respectively. The two radiation detectors (102, 104) are two photon counting detectors (PCDs), each of which is associated with an automatic image processing function. Regardless of the radiation dose received on the sensitive surface of the radiation detector (102, 104), the automatic image processing function automatically balances the image grayscale to make the response of the detector (102, 104) uniform.

34. A radiological imaging method according to any one of the preceding claims, characterized in that The two radiation detectors (102, 104) are respectively associated with the two radiation sources (101, 103), and the two radiation detectors (102, 104) are two multi-energy counting detectors, preferably two energy-resolved photon counting detectors (ERPCD).

35. The radiological imaging method according to any one of the preceding claims, characterized in that The radiation is X-rays.

36. A radiological imaging method according to any one of the preceding claims, characterized in that The second energy threshold is selected so as to improve image contrast more for lower patient thickness regions along the vertical direction than for higher patient thickness regions along the vertical direction. Preferably, the second energy threshold is between 50keV and 90keV, preferably between 60keV and 80keV, and more preferably, the second energy threshold is selected at 70keV.

37. A radiological imaging method according to any one of the preceding claims, characterized in that Depending on the patient's bone thickness and / or depending on the patient's soft tissue thickness and / or depending on the patient's specific bone positioning at different imaging positions along the vertical scanning direction, the first energy threshold and / or the second energy threshold are modified, and / or associated spectral filtering, preferably k-edge filtering, is used and tuned.

38. A radiological imaging method according to any one of the preceding claims, characterized in that: The front image and / or the side image are both single energy images obtained by (3) using the voltage intensity modulation of the front radiation source (101) and / or the side radiation source (103), Or the front image and / or the side image are both multi-energy images that are obtained without using voltage intensity modulation of the front radiation source (101) and / or the side radiation source (103).

Images