Radiographic imaging method using multi-energy scanning image

Abstract

The invention relates to a radiation imaging method comprising: two radiation detectors (122, 124) respectively associated with two radiation sources (121, 123) wherein the radiation method comprises at least one mode of operation in which: a front multi-energy exploration view and a side multi-energy exploration view are obtained (1) and combined and processed (20), the front radiation detector (122) is configured to estimate at least a patient bone thickness (22), at least a patient soft tissue thickness (22), a patient-specific bone position (21) at different imaging locations along a vertical scan direction, such that a front multi-energy image is obtained, and such that the front radiation detector (122) gives at least a first front image after a single vertical scan, the invention relates to a side radiation detector (124), referred to as a low-energy front image, a second front image, referred to as a high-energy front image, at least one combined front image corresponding to a combination of the first and second front images, and such that a side multi-energy image is obtained (3), and such that the side radiation detector (124) gives at least: a first side image, a second side image, a third side image, and a fourth side image. The invention relates to a method for generating a multi-energy image, referred to as a low-energy side image, a second side image, referred to as a high-energy side image, at least one combined side image corresponding to a combination of said first side image and said second side image, both a front multi-energy image and a side multi-energy image being obtained (3) during the same vertical scan.

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 the patient or one or more of the patient's organs or parts of the patient's organs, which is used for diagnosis by the practitioner,

[0004] - Radiological scan images dedicated to the distribution of bone density in a patient's body or in one or more of the patient's organs or in a portion of a patient's organ, for use in bone density assessment by a practitioner.

[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 one or more scan images are taken, which are then used by the practitioner for diagnosis or for bone density assessment.

[0007] The exploration view and the scanning image are performed by vertical scanning along the height of the standing patient, a front image capturing line including a front radiation source and a front radiation detector, and / or a side image capturing line including a side radiation source and a side radiation detector. Compared with the scanning image, the exploration view is performed with a radiation dose of about 10 times less or even less.

[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 given from the bone density image. Then, if a diagnosis is still required, not only a new scan image with different imaging parameters should be completed, but this new scan image does not 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, but at the same time partial images can be extracted from said 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 bone density assessment, since a standing patient is in exactly the same position for both.

[0012] Therefore, to be suitable for both diagnosis and bone density assessment with good quality, radiological methods use:

[0013] - First, a single energy or multi-energy exploration view. In the prior art, this exploration view is only a single energy view.

[0014] - Secondly, information is extracted from this exploration view, which is then used to make a multi-energy scan image, which in the prior art was only single-energy.

[0015] The multi-energy scan image will give even better results if performed after a multi-energy exploration view rather than after a single-energy exploration view.

[0016] The multi-energy scanning image may be a frontal image or a lateral image, or may include both a frontal image and a lateral image.

[0017] A first object of the present invention relates to a frontal multi-energy scanning image performed after a frontal single-energy exploration view.

[0018] This first object is achieved using a radiographic method comprising:

[0019] 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,

[0020] 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,

[0021] The radiation method comprises at least one operating mode in which:

[0022] A frontal single-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 and the frontal radiation detector,

[0023] processing the frontal exploratory view to identify patient thickness and specific bone locations at different positions along the vertical scanning direction within the frontal exploratory view,

[0024] modulating the intensity of the driving current of at least the frontal radiation source along the vertical scanning direction according to the identified patient thickness and according to the identified specific bone locations at different positions along the vertical scanning direction,

[0025] so that a frontal multi-energy image is obtained by performing a single vertical scan on a standing patient by the frontal radiation source and the frontal radiation detector along the vertical scanning direction,

[0026] o Modulating the driving current intensity of the frontal radiation source according to the patient thickness and according to the identified specific bone location at different positions along the vertical scanning direction, without modulating the voltage intensity of the frontal radiation source, is automatically performed in order to improve the compromise between:

[0027] ■ the total radiation dose received by the patient during said vertical scan,

[0028] ■ and, for at least one or more or preferably all frontal images given by said frontal radiation detector, the local image contrast of said identified specific bone location at different imaging positions along said vertical scanning direction,

[0029] The front radiation detector is configured to provide at least:

[0030] a first frontal image, corresponding to a first portion of the energy received by said frontal radiation detector and below a first given energy threshold, referred to as a low-energy frontal image,

[0031] a second frontal image, 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 image,

[0032] o At least one combined frontal image corresponding to a combination of the first frontal image and the second frontal image.

[0033] A second object of the present invention relates to a lateral multi-energy scanning image performed after the lateral single-energy exploration view.

[0034] This second object is achieved using a radiographic method comprising:

[0035] 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,

[0036] 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,

[0037] The radiation method comprises at least one operating mode in which:

[0038] A lateral single-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,

[0039] processing the lateral exploration view to identify patient thickness and specific bone locations at different locations along the vertical scanning direction within the lateral exploration view,

[0040] modulating the intensity of the driving current of at least the side radiation source along the vertical scanning direction according to the identified patient thickness and according to the identified specific bone locations at different positions along the vertical scanning direction,

[0041] so that a lateral multi-energy image is obtained by performing a single vertical scan on a standing patient along the vertical scanning direction by the lateral radiation source and the lateral radiation detector,

[0042] o Modulating the intensity of the driving current of the side radiation sources according to the patient thickness and according to the identified specific bone locations at different positions along the vertical scanning direction, without modulating the intensity of the voltage of the side radiation sources, is automatically performed in order to improve the compromise between:

[0043] ■ the total radiation dose received by the patient during said vertical scan,

[0044] ■ and, for at least one or more or preferably all lateral images given by said lateral radiation detector, the local image contrast of said identified specific bone location at different imaging positions along said vertical scanning direction,

[0045] The side radiation detector is configured to provide at least:

[0046] a first side image, 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 image,

[0047] a second side image, 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 image,

[0048] o At least one combined profile image corresponding to a combination of the first profile image and the second profile image.

[0049] The third object of the present invention relates to both a frontal multi-energy scanning image and a lateral multi-energy scanning image performed after both a frontal single-energy exploration view and a lateral single-energy exploration view.

[0050] This third object is achieved using a radiological imaging method comprising:

[0051] 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,

[0052] 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 respectively being two multi-energy counting detectors,

[0053] The radiation method comprises at least one operating mode in which:

[0054] A front single-energy exploration view and a side single-energy exploration view are obtained by performing a preliminary vertical scan on a standing patient along the vertical scanning direction using the front radiation source and the side radiation source and using the front radiation detector and the side radiation detector,

[0055] processing the frontal exploratory view and the lateral exploratory view to identify patient thickness and specific bone locations at different locations along the vertical scanning direction within the frontal exploratory view and the lateral exploratory view,

[0056] modulating the intensity of driving current of both the front radiation source and the side radiation source along the vertical scanning direction according to the identified patient thickness and according to the identified specific bone locations at different positions along the vertical scanning direction,

[0057] so that a frontal multi-energy image is obtained by performing a single vertical scan on a standing patient by the frontal radiation source and the frontal radiation detector along the vertical scanning direction,

[0058] o Modulating the driving current intensity of the frontal radiation source according to the patient thickness and according to the identified specific bone location at different positions along the vertical scanning direction, without modulating the voltage intensity of the frontal radiation source, is automatically performed in order to improve the compromise between:

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

[0060] ■ and, for at least one or more or preferably all frontal images given by said frontal radiation detector, the local image contrast of said identified specific bone location at different imaging positions along said vertical scanning direction,

[0061] The front radiation detector is configured to provide at least:

[0062] a first frontal image, corresponding to a first portion of the energy received by said frontal radiation detector and below a first given energy threshold, referred to as a low-energy frontal image,

[0063] a second frontal image, 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 image,

[0064] o at least one combined frontal image corresponding to a combination of said first frontal image and said second frontal image,

[0065] and obtaining a lateral multi-energy image by vertically scanning a standing patient along the vertical scanning direction by the lateral radiation source and the lateral radiation detector,

[0066] o Modulating the intensity of the driving current of the side radiation sources according to the patient thickness and according to the identified specific bone locations at different positions along the vertical scanning direction, without modulating the intensity of the voltage of the side radiation sources, is automatically performed in order to improve the compromise between:

[0067] ■ the total radiation dose received by the patient during the vertical scan,

[0068] ■ and said local image contrast of said identified specific bone location at different imaging positions along said vertical scanning direction for at least one or more or preferably all lateral images given by said lateral radiation detector,

[0069] Such that the side radiation detector gives at least:

[0070] a first side image, 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 image,

[0071] a second side image, 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 image,

[0072] o at least one combined profile image corresponding to a combination of the first profile image and the second profile image,

[0073] Both the frontal multi-energy image and the lateral multi-energy image are obtained during the same vertical scan.

[0074] A fourth object of the present invention relates to a frontal multi-energy scanning image performed after the frontal multi-energy exploration view.

[0075] This fourth object is achieved using a radiographic method comprising:

[0076] 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,

[0077] 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 respectively being two multi-energy counting detectors,

[0078] The radiation method comprises at least one operating mode in which:

[0079] 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:

[0080] 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,

[0081] 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,

[0082] The first frontal exploratory view and the second frontal exploratory view are combined and processed to evaluate:

[0083] ○At least the patient's bone thickness,

[0084] ○At least the patient's soft tissue thickness,

[0085] o patient-specific bone positioning at different imaging positions along the vertical scanning direction,

[0086] modulating the intensity of the driving current 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 identified specific bone locations at different positions along the vertical scanning direction,

[0087] so that a frontal multi-energy image is obtained by performing a single vertical scan on a standing patient by the frontal radiation source and the frontal radiation detector along the vertical scanning direction,

[0088] o Modulating the intensity of the driving current of the frontal radiation source according to the thickness of the patient's bone, according to the thickness of the patient's soft tissue and according to the identified specific bone location at different positions along the vertical scanning direction, without modulating the intensity of the voltage of the frontal radiation source, is automatically performed in order to improve the compromise between:

[0089] ■ the total radiation dose received by the patient during said vertical scan,

[0090] ■ and, for at least one or more or preferably all frontal images given by said frontal radiation detector, the local image contrast of said identified specific bone location at different imaging positions along said vertical scanning direction,

[0091] The front radiation detector is configured to provide at least:

[0092] a first frontal image, corresponding to a first portion of the energy received by said frontal radiation detector and below a first given energy threshold, referred to as a low-energy frontal image,

[0093] a second frontal image, 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 image,

[0094] o At least one combined frontal image corresponding to a combination of the first frontal image and the second frontal image.

[0095] A fifth object of the present invention relates to a lateral multi-energy scanning image performed after the lateral multi-energy exploration view.

[0096] This fifth object is achieved using a radiographic method comprising:

[0097] 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,

[0098] 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 respectively being two multi-energy counting detectors,

[0099] The radiation method comprises at least one operating mode in which:

[0100] 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:

[0101] 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,

[0102] 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,

[0103] The first lateral exploratory view and the second lateral exploratory view are combined and processed to evaluate:

[0104] ○At least the patient's bone thickness,

[0105] ○At least the patient's soft tissue thickness,

[0106] o patient-specific bone positioning at different imaging positions along the vertical scanning direction,

[0107] modulating the intensity of the driving current 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 identified specific bone locations at different positions along the vertical scanning direction,

[0108] so that a lateral multi-energy image is obtained by performing a single vertical scan on a standing patient along the vertical scanning direction by the lateral radiation source and the lateral radiation detector,

[0109] o Modulating the intensity of the driving current of the side radiation source according to the thickness of the patient's bone, according to the thickness of the patient's soft tissue and according to the identified specific bone location at different positions along the vertical scanning direction, without modulating the intensity of the voltage of the side radiation source, is automatically performed in order to improve the compromise between:

[0110] ■ the total radiation dose received by the patient during said vertical scan,

[0111] ■ and, for at least one or more or preferably all lateral images given by said lateral radiation detector, the local image contrast of said identified specific bone location at different imaging positions along said vertical scanning direction,

[0112] The side radiation detector is configured to provide at least:

[0113] a first side image, 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 image,

[0114] a second side image, 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 image,

[0115] o At least one combined profile image corresponding to a combination of the first profile image and the second profile image.

[0116] The sixth object of the present invention relates to both a frontal multi-energy scanning image and a lateral multi-energy scanning image performed after both a frontal multi-energy probing view and a lateral multi-energy probing view.

[0117] This sixth object is achieved using a radiographic method comprising:

[0118] 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,

[0119] 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 respectively being two multi-energy counting detectors,

[0120] The radiation method comprises at least one operating mode in which:

[0121] 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:

[0122] 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,

[0123] 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,

[0124] 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,

[0125] 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,

[0126] 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:

[0127] ○At least the patient's bone thickness,

[0128] ○At least the patient's soft tissue thickness,

[0129] o patient-specific bone positioning at different imaging positions along the vertical scanning direction,

[0130] modulating the intensity of the driving current 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 identified specific bone locations at different positions along the vertical scanning direction,

[0131] so that a frontal multi-energy image is obtained by performing a single vertical scan on a standing patient by the frontal radiation source and the frontal radiation detector along the vertical scanning direction,

[0132] o Modulating the intensity of the driving current of the frontal radiation source according to the thickness of the patient's bone, according to the thickness of the patient's soft tissue and according to the identified specific bone location at different positions along the vertical scanning direction, without modulating the intensity of the voltage of the frontal radiation source, is automatically performed in order to improve the compromise between:

[0133] ■ the total radiation dose received by the patient during said vertical scan,

[0134] ■ and, for at least one or more or preferably all frontal images given by said frontal radiation detector, the local image contrast of said identified specific bone location at different imaging positions along said vertical scanning direction,

[0135] The front radiation detector is configured to provide at least:

[0136] a first frontal image, corresponding to a first portion of the energy received by said frontal radiation detector and below a first given energy threshold, referred to as a low-energy frontal image,

[0137] a second frontal image, 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 image,

[0138] o at least one combined frontal image corresponding to a combination of said first frontal image and said second frontal image,

[0139] and obtaining a lateral multi-energy image by vertically scanning a standing patient along the vertical scanning direction by the lateral radiation source and the lateral radiation detector,

[0140] o Modulating the intensity of the driving current of the side radiation source according to the thickness of the patient's bone, according to the thickness of the patient's soft tissue and according to the identified specific bone location at different positions along the vertical scanning direction, without modulating the intensity of the voltage of the side radiation source, is automatically performed in order to improve the compromise between:

[0141] ■ the total radiation dose received by the patient during the vertical scan,

[0142] ■ and said local image contrast of said identified specific bone location at different imaging positions along said vertical scanning direction for at least one or more or preferably all lateral images given by said lateral radiation detector,

[0143] Such that the side radiation detector gives at least:

[0144] a first side image, 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 image,

[0145] a second side image, 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 image,

[0146] o at least one combined profile image corresponding to a combination of the first profile image and the second profile image,

[0147] Both the frontal multi-energy image and the lateral multi-energy image are obtained during the same vertical scan.

[0148] The present invention relates not only to the radiation methods listed above, but also to radiation devices for respectively carrying out these radiation methods.

[0149] In all the aforementioned objects of the present invention, unless mentioned to the contrary, a combined image (whether frontal, side or both) corresponding to a combination of the first image and the second image merely means that this combined image is equal to the result of the combination of the first image and the second image, not that the combined image has been obtained in the manner described. The detector may, for example, directly give the combined image and the second image, and then obtain the first image by subtracting the second image from the combined image.

[0150] 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.

[0151] Preferably,

[0152] 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,

[0153] ○ Preferably, a bi-material decomposition between Al and PMMA, or a bi-material decomposition between HA (hydroxyapatite) and H2O,

[0154] 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,

[0155] ○ Preferably, a bi-material decomposition between Al and PMMA, or a bi-material decomposition between HA and H2O.

[0156] 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.

[0157] Preferably,

[0158] The frontal single-energy exploration view is obtained by performing a single preliminary vertical scan on a standing patient along the vertical scanning direction by the frontal radiation source and by the frontal radiation detector,

[0159] The lateral single-energy exploration view is obtained by performing a single preliminary vertical scan of a standing patient along the vertical scanning direction by the lateral radiation source and by the lateral radiation detector,

[0160] Both the frontal single-energy probing view and the lateral single-energy probing view are obtained during the same single vertical scan.

[0161] 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.

[0162] 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.

[0163] Thus, in both cases, all energy threshold ranges are covered, with lower costs in the second case.

[0164] Preferably,

[0165] The first given energy threshold is equal to the second given energy threshold,

[0166] The front multi-energy image and / or the side multi-energy image are obtained so that the front radiation detector and / or the side radiation detector firstly gives:

[0167] ○ the first frontal image,

[0168] o a third frontal image, corresponding to the total energy received by the frontal radiation detector, called the total energy frontal image,

[0169] ■ obtaining the second frontal image by subtracting the first frontal image from the third frontal image,

[0170] ○ and / or the first side image,

[0171] o and / or a third lateral image, which corresponds to the total energy received by said lateral radiation detector, called the total energy lateral image,

[0172] ■ The second lateral image is obtained by subtracting the first lateral image from the third lateral image.

[0173] Therefore, the total energy image and the high energy image can be given directly by the detector, while the low energy image can be obtained by a simple subtraction, by subtracting the high energy image from the total energy image.

[0174] Preferably,

[0175] 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:

[0176] o said modulating along said vertical scanning direction the intensity of the driving current of at least said frontal radiation source according to said patient thickness and according to said specific bone positioning at different positions along said vertical scanning direction,

[0177] 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:

[0178] o said modulating the intensity of the driving current of at least said side radiation source along said vertical scanning direction according to said patient thickness and according to said specific bone location at different positions along said vertical scanning direction,

[0179] Both the frontal image and the lateral image are obtained during the same vertical scan.

[0180] 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.

[0181] Preferably,

[0182] 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:

[0183] ■ reducing the total radiation dose received by the patient during the vertical scan,

[0184] ■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 not reduced at a given contrast threshold.

[0185] This means that it is possible to:

[0186] - Achieve the lowest possible total radiation dose while maintaining the correct predetermined image quality,

[0187] - or improve image quality without increasing the total radiation dose too much,

[0188] - 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.

[0189] Preferably,

[0190] 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:

[0191] ■ reducing the total radiation dose received by the patient during the vertical scan,

[0192] ■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.

[0193] This means that it is possible to:

[0194] - Achieve the lowest possible total radiation dose while maintaining the intended good image quality,

[0195] - or profoundly improve image quality without increasing total radiation dose,

[0196] - 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.

[0197] Preferably,

[0198] The frontal multi-energy image is acquired using at least 2 energy bins, or using at least 3 energy bins, or using at least 6 energy bins,

[0199] ○ and / or up to 20 energy bins, or up to 15 energy bins, or up to 10 energy bins,

[0200] and / or using at least 2 energy bins or using at least 3 energy bins or using 6 energy bins to acquire the side multi-energy image,

[0201] ○ and / or up to 20 energy bins, or up to 15 energy bins, or up to 10 energy bins.

[0202] 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.

[0203] Preferably,

[0204] For each of said radiation detectors:

[0205] 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,

[0206] ○ 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,

[0207] 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,

[0208] And / or the radiation detector is operable in a time delay and sum mode.

[0209] As a result, the image will have better resolution without too many artifacts and will cover the total useful width of the patient.

[0210] Preferably, said identified specific skeletal location comprises the patient's spine, preferably the patient's spine.

[0211] 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.

[0212] 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.

[0213] Preferably, the driving current intensity modulation of the front radiation source and / or the side radiation source is also performed to achieve a certain signal-to-noise ratio value, and for the front image and / or for the side image, the signal-to-noise ratio value 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.

[0214] 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.

[0215] Preferably,

[0216] 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%,

[0217] 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.

[0218] Therefore, 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, as this is the actual area of ​​interest within the frontal image and / or the lateral image.

[0219] Preferably, the front image and / or the side image are normalized by homogenization of the original radiation after having undergone at least the local image contrast improvement so as to eliminate image artifacts from the drive current intensity modulation, and preferably wherein the front image and / or the side image undergo a contrast enhancement step after having been normalized.

[0220] 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 of the radiographic method operator.

[0221] 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.

[0222] 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 very detrimental to the patient.

[0223] Preferably, the current intensity modulation is maximized so as to also maximize the vertical scanning speed to a constant value.

[0224] 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.

[0225] Preferably, the operating mode can be switched on or off manually by an operator of the radiographic method.

[0226] 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.

[0227] 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.

[0228] 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.

[0229] 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.

[0230] 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.

[0231] Preferably, the current intensity modulation is at least in the range of 20 mA to 300 mA, and preferably 10 mA to 400 mA.

[0232] 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.

[0233] 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.

[0234] 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.

[0235] 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.

[0236] 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.

[0237] 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.

[0238] 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.

[0239] 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.

[0240] 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.

[0241] 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.

[0242] 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.

[0243] 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.

[0244] 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 density to make the response of the detector uniform regardless of the radiation dose received on the sensitive surface of the radiation detector.

[0245] 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 compared to gas detectors.

[0246] 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).

[0247] Preferably, the radiation is X-rays.

[0248] 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.

[0249] Preferably, the voltage intensity of the front radiation source is greater than 90 kVp, or more preferably greater than 100 kVp.

[0250] Therefore, it will become easier to distinguish between bone and soft tissue in the patient's body.

[0251] 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.

[0252] Thus, even though a wider patient chest may still be accurately seen, narrower arms or legs will not be sacrificed at all or almost not at all due to being undersaturated or very lightly saturated (ie, overexposure due to system limitations).

[0253] Preferably, the first energy threshold and / or the second energy threshold are modified according to the patient 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.

[0254] Thus, even the accuracy of the end-user images used by practitioners is improved.

[0255] Preferably,

[0256] o the second frontal image contains information allowing the assessment of the patient's bone density, and the second lateral image contains information allowing the assessment of the patient's bone density,

[0257] ○ and / or the combined frontal image presents the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction, and the local image contrast is sufficient to diagnose the patient, and the combined lateral image presents the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction, and the local image contrast is sufficient to diagnose the patient.

[0258] Thus, using one global operation, two different kinds of images have been processed, resulting in two different useful applications for practitioners.

[0259] For all the aforementioned objects and / or all the aforementioned combinations of the present invention, a mechanical cross scatter correction with vertical gap, as described for example in patent applications EP 16711889 or US1607660, and / or a software cross scatter correction, as described for example in patent applications EP 17758269 or US16628410 may be added.

[0260] Preferably, the multi-energy image is a dual-energy image.

[0261] 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

[0262] 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.

[0263] Figure 2 An example of a multi-energy exploration view acquisition step in a radiation imaging method according to an embodiment of the present invention and / or a multi-energy scanning image acquisition step in a radiation imaging method according to an embodiment of the present invention is shown.

[0264] Figure 3 Another example of a multi-energy exploration view acquisition step in a radiation imaging method according to an embodiment of the present invention and / or a multi-energy scanning image acquisition step in a radiation imaging method according to an embodiment of the present invention is shown.

[0265] Figure 4 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.

[0266] Figure 5 An example of a portion of a patient bone and soft tissue thickness calculation step and / or a patient total thickness calculation within a radiological imaging method according to an embodiment of the present invention is shown.

[0267] Figure 6 A first example of another part of the patient total thickness calculation step in the radiographic imaging method according to an embodiment of the present invention is shown.

[0268] Figure 7 A second 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.

[0269] Figure 8 An example of a frontal patient single-energy diagnostic image not according to an embodiment of the invention is shown, which has no additional possibility of obtaining the calculation of a bone density distribution image of good quality.

[0270] Fig. 9 An example of a frontal patient multi-energy (dual energy) image according to an embodiment of the invention is shown with the additional possibility of obtaining calculation of a good quality bone density distribution image.

[0271] Fig.10 Show Figure 8 Magnification of the thoracic region.

[0272] Fig.11 Show Fig. 9 Magnification of the thoracic region.

[0273] Fig.12 An example of the execution of the bone density calculation step in the radiological imaging method according to the embodiment of the present invention is shown.

[0274] Fig.13 Shown as Fig.12 An example of continuous image transformation during application of a bone density calculation step within a radiological imaging method according to an embodiment of the present invention is shown.

[0275] Fig.14 An example of a table comparing bone density values ​​between a DXA image on one side that is not in accordance with an embodiment of the present invention (without the additional possibility of obtaining a good quality diagnosis) and a bone density image on one side that is in accordance with an embodiment of the present invention (with the calculated additional possibility of obtaining a good quality diagnosis).

[0276] Fig.15 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. DETAILED DESCRIPTION

[0277] 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 or may be less accurate.

[0278] 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.

[0279] In a first alternative, multi-energy images and even dual-energy images are taken based on a single-energy exploratory view acquisition.

[0280] First, step 1 of acquiring a front exploratory view and a side exploratory view is performed.

[0281] Next, a 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 the patient's thickness, and then the patient's thickness distribution along the patient's height is processed by extracting the thickness values ​​along the coordinates of the distribution of interest. At the end of the thickness distribution extraction step 20, the patient's thickness distribution along the patient's height can be used for the next step, which is a determination and selection step 23. The patient's thickness distribution along the patient's height corresponds to the total thickness along the patient's height, including both the patient's bone thickness and the patient's soft tissue thickness.

[0282] Next, a step 23 is performed to determine a fixed voltage value (in kV) and a spectral filter, as well as to select a detector energy threshold, based on the patient thickness distribution along the patient height from a model and / or reference table 24 containing a catalog of models and / or references. 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, there are spectral filters, fixed voltage values, one or more detector energy thresholds available for the next calculation step 26.

[0283] Next, 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 patient height. Calculation step 26 also uses exposure target 25. The calculation step also performs a feedback loop towards determination and selection step 23. At the end of calculation step 26, spectral filtering, fixed voltage value, one or more detector energy thresholds, vertical scan acquisition speed (in mm / sec), current modulation distribution in mA along the patient height are available for the next image acquisition step 3. The current modulation distribution along the patient height and other parameters will also be directly available for image normalization step 4 and bone density calculation step 7.

[0284] In this calculation step 26, 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 patient height are performed. For a given voltage value, the current distribution and the vertical scan speed selection strategy are similar to the strategy used in patent application WO2021 / 094806 (hereby incorporated by reference). In summary:

[0285] - Calculate the exposure budget (the product of the current value required to achieve the exposure target and the exposure time),

[0286] - maximize the vertical scan speed given the available tube current budget (constrained by the hardware specifications in terms of maximum tube power and maximum instantaneous current value),

[0287] - From this the corresponding current distribution is calculated.

[0288] 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) is

[0289]

[0290] 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.

[0291] 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 be satisfied.

[0292] 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 ).

[0293] All steps 20 , 23 , 24 , 25 , 26 are part of the exposure parameter calculation routine 2 .

[0294] 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), current modulation distribution along the patient height (in mA). This acquired image is a multi-energy image, and even a dual-energy image here. The acquired image may include a frontal image and / or a side image. The acquired image preferably includes a frontal image and a side image.

[0295] Based on the multi-energy image and the current intensity modulation distribution acquired at the acquisition step 3, the frontal acquired image and the lateral acquired image are then normalized in a normalization step 4. The frontal normalized image and the lateral normalized image may then be further processed in some manner (using a post-processing step) in a diagnostic image processing chain step 5 and / or may be subsequently displayed on a screen for the practitioner to see, so as to provide the practitioner with a diagnostically good quality image of the patient.

[0296] The diagnostic image processing chain 5 corresponds to the standard image processing chain usually used with single energy image acquisition, but applied to the combination of the low energy and the high energy normalized image, ie to the sum of the low energy image and the high energy image.

[0297] Based on the multi-energy image and current intensity modulation distribution acquired at the acquisition step 3 and other available parameters, the front-acquired image and the side-acquired image are further processed in another manner (using other post-processing steps) in the bone density calculation step 7 to provide the practitioner with a bone density calculation distribution, which can also be displayed to the practitioner.

[0298] In a second alternative, a multi-energy image, and here even a dual-energy image, is performed based on a multi-energy and even a dual-energy exploratory view acquisition.

[0299] First, step 1 of acquiring a front exploratory view and a side exploratory view is performed.

[0300] 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)}.

[0301] At the end of the thickness distribution extraction step 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 the determination and selection step 23 .

[0302] 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.

[0303] 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 / second), 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 and the bone density calculation step 7.

[0304] In this calculation step 26, 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 patient height are performed. For a given voltage value, the current distribution and the vertical scan speed selection strategy are similar to the strategy used in patent application WO2021 / 094806 (hereby incorporated by reference). In summary:

[0305] - Calculate the exposure budget (the current value required to achieve the exposure target multiplied by the exposure time),

[0306] - 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),

[0307] - From this the corresponding current distribution is calculated.

[0308] 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

[0309]

[0310] 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.

[0311] 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 be satisfied.

[0312] 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 ).

[0313] All steps 20 , 23 , 24 , 25 , 26 are part of the exposure parameter calculation routine 2 .

[0314] 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 is a multi-energy image, and even a dual-energy image. The acquired image may include a frontal image and / or a lateral image. The acquired image preferably includes a frontal image and a lateral image.

[0315] Based on the multi-energy image and the current intensity modulation profile acquired at acquisition step 3 and other available parameters, the frontal acquired image and the lateral acquired image are then normalized in a normalization step 4. The frontal normalized image and the lateral normalized image may then be further processed in some manner (using a post-processing step) in a diagnostic image processing chain step 5 and / or subsequently displayed on a screen for the practitioner to see, so as to provide the practitioner with a diagnostic quality image of the patient.

[0316] The diagnostic image processing chain 5 corresponds to the standard image processing chain usually used with single energy image acquisition, but applied to the combination of the low energy and the high energy normalized image, ie to the sum of the low energy image and the high energy image.

[0317] Based on the multi-energy image and current intensity modulation distribution acquired at the acquisition step 3 and other available parameters, the front-acquired image and the side-acquired image are further processed in another manner (using other post-processing steps) in the bone density calculation step 7 to provide the practitioner with a bone density calculation distribution, which can also be displayed to the practitioner.

[0318] Figure 2 An example of a multi-energy exploration view acquisition step in a radiation imaging method according to an embodiment of the present invention and / or a multi-energy scanning image acquisition step in a radiation imaging method according to an embodiment of the present invention is shown.

[0319] exist Figure 1 In the multi-energy probing view acquisition step 1 in , the normalized attenuation spectrum AS is expressed as a function of the energy E expressed in keV.

[0320] 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.

[0321] 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.

[0322] exist Figure 1 In the multi-energy image acquisition step 3 in , the normalized attenuation spectrum AS is expressed as a function of the energy E expressed in keV.

[0323] In multi-energy image acquisition, the detector directly reads the low-energy image and the high-energy image, and derives the total energy image by adding the high-energy image and the low-energy image together.

[0324] Figure 3 Another example of a multi-energy exploration view acquisition step in a radiation imaging method according to an embodiment of the present invention and / or a multi-energy scanning image acquisition step in a radiation imaging method according to an embodiment of the present invention is shown.

[0325] exist Figure 1 In the multi-energy probing view acquisition step 1 in , the attenuation spectrum AS is expressed as a function of the energy E expressed in keV.

[0326] 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.

[0327] 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.

[0328] exist Figure 1 In the multi-energy image acquisition step 3 in , the attenuation spectrum AS is expressed as a function of the energy E expressed in keV.

[0329] In multi-energy image acquisition, the detector reads a total energy image and a high energy image, and a low energy image is derived by subtracting the high energy image from the total energy image.

[0330] Figure 4 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.

[0331] exist Figure 4 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.

[0332] These salient points 60 represent curves extracted from the patient lateral 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.

[0333] This is how sub-step 21 of the bone positioning calculation is performed.

[0334] Figure 5 An example of a portion of a patient bone and soft tissue thickness calculation step and / or a patient total thickness calculation within a radiological imaging method according to an embodiment of the present invention is shown.

[0335] In the first alternative multi-energy case, each pass Figure 7 The online thickness calculation 222 of the online operation 222 uses the Figure 5 The offline signal to thickness mapping calibration offline operation 221 performs sub-step 22 of calculating both the patient's bone thickness and soft tissue thickness using information obtained offline alone.

[0336] 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.

[0337] In the single energy case of the second alternative, each time through Figure 6 The online thickness calculation 223 on the online operation 223 uses the Figure 5 The offline signal to thickness mapping calibration offline operation 221 performs the sub-step 22 of calculating the patient thickness using the information obtained offline.

[0338] In the offline operation 221 of the offline signal to thickness mapping calibration, the exploration exposure parameters 2211 and the known material thickness 2212 are used as input to the measurement or simulation 2213, which gives the measured or simulated detector signal 2214 as output. Then, both the known material thickness 2212 and the measured or simulated detector signal 2214 are saved and stored in the 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. Due to the single energy exploration view, the mapping is based on the total energy signal corresponding to the total signal, and a mapping of the total thickness of one material (soft tissue) is calculated. The PMMA thickness is stored in the high energy and low energy coordinate systems.

[0339] Figure 6 A first example is shown of another part of the total patient thickness calculation step within the radiological imaging method according to an embodiment of the present invention, which step is performed at the beginning of a single energy case.

[0340] In an online operation 223 of online thickness calculation, the measured detector signal 2231 is used as input to a simplified database 2232 or to a portion 2232 of the database 2215, storing a signal to PMMA thickness (corresponding to total thickness) mapping. The database 2232 storing the signal to PMMA thickness mapping gives the patient total thickness 2233 as output.

[0341] Figure 7 A second 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.

[0342] 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 the bone thickness 2223. The sub-database 2224 storing the signal to soft tissue thickness mapping gives as output the soft tissue thickness 2225.

[0343] Figure 8 An example of a frontal patient mono-energy diagnostic image not according to an embodiment of the invention is shown, which has no additional possibility of calculation to obtain a good quality bone density distribution image.A good quality frontal diagnostic image 80 with a thoracic region 81 shows a patient spine.

[0344] Fig. 9 An example of a frontal patient multi-energy (dual energy) image according to an embodiment of the invention is shown with the additional possibility of calculation of obtaining good quality bone density distribution images.A good quality frontal diagnostic image 90 with thoracic region 91 shows a patient spine.

[0345] Fig.10 Show Figure 8 The thorax region 81 is represented by a good quality diagnostic frontal image derived from the acquired frontal image, but no additional calculation of good quality bone density distribution can be derived from the acquired frontal image.

[0346] Fig.11 Show Fig. 9 The thoracic region 91 is represented by a good quality diagnostic frontal image derived from the acquired frontal image, and further, additional calculations of good quality bone density distribution can be derived from this acquired frontal image.

[0347] Fig.12 An example of the execution of the bone density calculation step in the radiological imaging method according to the embodiment of the present invention is shown.

[0348] Fig.13 Shown as Fig.12 An example of continuous image transformation during application of a bone density calculation step within a radiological imaging method according to an embodiment of the present invention is shown.

[0349] When reference Figure 1 When the multi-energy image is acquired, bone density calculation 7 can be performed after step 3 of acquiring the multi-energy image.

[0350] spectral filtering, fixed voltage values, one or more detector energy thresholds, vertical scan acquisition speed (in mm / sec), current modulation profile along patient height (in mA), and calibrated signal-to-thickness mapping of database 2215 (in Figure 5 (above) can be used for the patient's two material thickness basis calculation sub-step 71 to obtain the first transformation of images 73 and 74, low energy images and high energy images acquired after the multi-energy image acquisition step 3 to images 75 and 76, Al images and PMMA images.

[0351] Next, by using the offline calibration model 70, these images 75 and 76, the Al image and the PMMA image are transformed and combined into a BMD image 77 (bone mineral density image, also more simply called bone density image) through a sub-step 72 of conversion to bone mineral density.

[0352] Fig.14 An example of a table comparing bone density values ​​between a DXA image on one side that is not in accordance with an embodiment of the present invention (without the additional possibility of obtaining a good quality diagnosis) and a bone density image on one side that is in accordance with an embodiment of the present invention (with the calculated additional possibility of obtaining a good quality diagnosis).

[0353] DXA columns 101, 102, 103 corresponding to low, medium and high bone density, respectively, are extracted from the prior art papers "Nowak, T., Eberhard, M., Schmidt, B., Frey, D., Distler, O., Saltybaeva, N., ... & Euler, A. (2021)" and "Bone mineral density quantification from localizer radiographs: accurate precision of energy-integrating detector CT and photon-counting detector CT. Radiology, 298 (1), 147-152". The values ​​are measured on the European Spine Phantom (ESP).

[0354] By comparing with DXA columns 101, 102, 103, the bone mineral density images obtained by the embodiment of the present invention are at least as good as the bone mineral density images of the prior art "Nowak et al. (2021)", and sometimes even better, as can be seen from the "invention columns" 111, 112, 113 corresponding to low, medium and high bone density, respectively. In addition, using the multi-energy images acquired in step 3 according to the embodiment of the present invention, good quality diagnostic images can be additionally derived, which cannot be accomplished using the prior art "Nowak et al. (2021)".

[0355] Multi-energy image acquisition according to an embodiment of the present invention allows both:

[0356] - Export good quality images,

[0357] - Export good quality bone density images,

[0358] The process according to the prior art can only derive one of the two types of images from the same image acquisition step, but cannot derive both types of images.

[0359] Fig.15 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.15 The patient height is also orthogonal to Fig.15 The vertical scanning direction is the patient height scanning direction, so the scanning direction is along the patient height of a standing patient.

[0360] An imaging device or imaging apparatus 129 is present.

[0361] The frontal transmit and receive line includes a frontal tube 121 which emits an X-ray frontal beam 125 which passes through the patient's body (not shown here but located in the intersection region 128 ) and reaches a frontal detector 122 .

[0362] The side transmit and receive line includes a side tube 123 that transmits a side beam 126 of X-rays that passes through the patient's body (not shown here but located in an intersection region 128) and reaches a side detector 124.

[0363] To avoid cross scatter in the intersection region 128, 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 mentioned above.

[0364] 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 (121, 123) whose imaging directions are orthogonal to each other, a front radiation source (121) and a side radiation source (123), wherein the radiation sources slide vertically so as to vertically scan a standing patient along a vertical scanning direction, Two radiation detectors (122, 124) respectively associated with the two radiation sources (121, 123), a front radiation detector (122) and a side radiation detector (124), the radiation detectors vertically sliding to vertically scan a standing patient along the vertical scanning direction, at least the front radiation detector (122) being a multi-energy counting detector, The radiation method comprises at least one operating mode, in which: (1) a front single energy exploration view is obtained by performing a preliminary vertical scan on a standing patient along the vertical scanning direction by the front radiation source (121) and the front radiation detector (122), processing (20) the frontal exploratory view to identify patient thickness (22) and specific bone locations (21) at different positions along the vertical scanning direction within the frontal exploratory view, modulating the intensity of a driving current of at least the front radiation source (121) along the vertical scanning direction according to the identified patient thickness and according to the identified specific bone locations at different positions along the vertical scanning direction, (3) a frontal multi-energy image is obtained by performing a single vertical scan on a standing patient along the vertical scanning direction by the frontal radiation source (121) and the frontal radiation detector (122), o Modulating the intensity of the driving current of the front radiation source (121) according to the patient thickness and according to the identified specific bone location at different positions along the vertical scanning direction, without modulating the intensity of the voltage of the front radiation source (121), this is automatically performed in order to improve the compromise between: ■ the total radiation dose received by the patient during said vertical scan, ■ and for at least one or more or preferably all frontal images given by the frontal radiation detector (122), local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction, The front radiation detector (122) provides at least: a first frontal image, corresponding to a first portion of energy received by said frontal radiation detector (122) and below a first given energy threshold, referred to as a low energy frontal image, a second frontal image, corresponding to a second portion of the energy received by the frontal radiation detector (122) and above a second given energy threshold, referred to as a high energy frontal image, o At least one combined frontal image corresponding to a combination of the first frontal image and the second frontal image.

2. A radiographic imaging method, comprising: Two radiation sources (121, 123) whose imaging directions are orthogonal to each other, a front radiation source (121) and a side radiation source (123), wherein the radiation sources slide vertically so as to vertically scan a standing patient along a vertical scanning direction, Two radiation detectors (122, 124) respectively associated with the two radiation sources (121, 123), a front radiation detector (122) and a side radiation detector (124), the radiation detectors vertically sliding to vertically scan a standing patient along the vertical scanning direction, at least the side radiation detector (124) being a multi-energy counting detector, The radiation method comprises at least one operating mode, in which: (1) a lateral single 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 (123) and the lateral radiation detector (124), processing (20) the lateral exploration view to identify patient thickness (22) and specific bone locations (21) at different positions along the vertical scanning direction within the lateral exploration view, modulating the intensity of the driving current of at least the side radiation source (123) along the vertical scanning direction according to the identified patient thickness and according to the identified specific bone locations at different positions along the vertical scanning direction, (3) a lateral multi-energy image is obtained by performing a single vertical scan on a standing patient along the vertical scanning direction by the lateral radiation source (123) and the lateral radiation detector (124), o Modulating the intensity of the driving current of the side radiation source (123) according to the patient thickness and according to the identified specific bone location at different positions along the vertical scanning direction, without modulating the intensity of the voltage of the side radiation source (123), this is automatically performed in order to improve the compromise between: ■ the total radiation dose received by the patient during said vertical scan, ■ and for at least one or more or preferably all lateral images given by the lateral radiation detector (124), the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction, The side radiation detector (124) provides at least: a first side image, corresponding to a first portion of the energy received by said side radiation detector (124) and below a first given energy threshold, referred to as a low energy side image, a second side image corresponding to a second portion of the energy received by the side radiation detector (124) and above a second given energy threshold, referred to as a high energy side image, o At least one combined profile image corresponding to a combination of the first profile image and the second profile image.

3. A radiographic imaging method, comprising: Two radiation sources (121, 123) whose imaging directions are orthogonal to each other, a front radiation source (121) and a side radiation source (123), wherein the radiation sources slide vertically so as to vertically scan a standing patient along a vertical scanning direction, Two radiation detectors (122, 124) respectively associated with the two radiation sources (121, 123), a front radiation detector (122) and a side radiation detector (124), the radiation detectors vertically sliding to vertically scan a standing patient along the vertical scanning direction, the two radiation detectors (122, 124) respectively being two multi-energy counting detectors, The radiation method comprises at least one operating mode, in which: (1) a front single-energy exploration view and a side single-energy exploration view are obtained by performing a preliminary vertical scan on a standing patient along the vertical scanning direction using the front radiation source and the side radiation source (121, 123) and the front radiation detector and the side radiation detector (122, 124), processing (20) the frontal exploration view and the lateral exploration view to identify patient thickness (22) and specific bone locations at different locations (21) along the vertical scanning direction within the frontal exploration view and the lateral exploration view, modulating the intensity of driving current of both the front radiation source and the side radiation source (121, 123) along the vertical scanning direction according to the identified patient thickness and according to the identified specific bone locations at different positions along the vertical scanning direction, (3) a frontal multi-energy image is obtained by performing a single vertical scan on a standing patient along the vertical scanning direction by the frontal radiation source (121) and the frontal radiation detector (122), o Modulating the intensity of the driving current of the front radiation source (121) according to the patient thickness and according to the identified specific bone location at different positions along the vertical scanning direction, without modulating the intensity of the voltage of the front radiation source (121), this is automatically performed in order to improve the compromise between: ■ the total radiation dose received by the patient during said vertical scan, ■ and for at least one or more or preferably all frontal images given by the frontal radiation detector (122), local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction, The front radiation detector (122) provides at least: a first frontal image, corresponding to a first portion of energy received by said frontal radiation detector (122) and below a first given energy threshold, referred to as a low energy frontal image, a second frontal image, corresponding to a second portion of the energy received by the frontal radiation detector (122) and above a second given energy threshold, referred to as a high energy frontal image, o at least one combined frontal image corresponding to a combination of said first frontal image and said second frontal image, and obtaining (3) a lateral multi-energy image by vertically scanning a standing patient along the vertical scanning direction by the lateral radiation source and the lateral radiation detector (124), o Modulating the intensity of the driving current of the side radiation source (123) according to the patient thickness and according to the identified specific bone location at different positions along the vertical scanning direction, without modulating the intensity of the voltage of the side radiation source (123), this is automatically performed in order 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 at least one or more or preferably all lateral images given by the lateral radiation detector (124), The side radiation detector (124) is configured to provide at least: a first side image, corresponding to a first portion of the energy received by said side radiation detector (124) and below a first given energy threshold, referred to as a low energy side image, a second side image corresponding to a second portion of the energy received by the side radiation detector (124) and above a second given energy threshold, referred to as a high energy side image, o at least one combined profile image corresponding to a combination of the first profile image and the second profile image, Both (3) the frontal multi-energy image and the lateral multi-energy image are obtained during the same vertical scan.

4. A radiographic imaging method, comprising: Two radiation sources (121, 123) whose imaging directions are orthogonal to each other, a front radiation source (121) and a side radiation source (123), wherein the radiation sources slide vertically so as to vertically scan a standing patient along a vertical scanning direction, Two radiation detectors (122, 124) respectively associated with the two radiation sources (121, 123), a front radiation detector (122) and a side radiation detector (124), the radiation detectors vertically sliding to vertically scan a standing patient along the vertical scanning direction, the two radiation detectors (122, 124) respectively being two 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 (121) and the frontal radiation detector (122), so that the frontal radiation detector (122) at least provides: a first frontal exploration view corresponding to a first portion of energy received by the frontal radiation detector (122) 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 (122) 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 (21) at different imaging positions along the vertical scanning direction, modulating the intensity of the driving current of the front radiation source (121) along the vertical scanning direction according to the patient's bone thickness, according to the patient's soft tissue thickness and according to the identified specific bone locations at different positions along the vertical scanning direction, (3) a frontal multi-energy image is obtained by performing a single vertical scan on a standing patient along the vertical scanning direction by the frontal radiation source (121) and the frontal radiation detector (122), o Modulating the intensity of the driving current of the front radiation source (121) according to the thickness of the patient's bone, according to the thickness of the patient's soft tissue and according to the identified specific bone location at different positions along the vertical scanning direction, without modulating the intensity of the voltage of the front radiation source (121), which is automatically performed in order to improve the compromise between: ■ the total radiation dose received by the patient during said vertical scan, ■ and for at least one or more or preferably all frontal images given by the frontal radiation detector (122), local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction, The front radiation detector (122) provides at least: a first frontal image, corresponding to a first portion of energy received by said frontal radiation detector (122) and below a first given energy threshold, referred to as a low energy frontal image, a second frontal image, corresponding to a second portion of the energy received by the frontal radiation detector (122) and above a second given energy threshold, referred to as a high energy frontal image, o At least one combined frontal image corresponding to a combination of the first frontal image and the second frontal image.

5. A radiographic imaging method, comprising: Two radiation sources (121, 123) whose imaging directions are orthogonal to each other, a front radiation source (121) and a side radiation source (123), wherein the radiation sources slide vertically so as to vertically scan a standing patient along a vertical scanning direction, Two radiation detectors (122, 124) respectively associated with the two radiation sources (121, 123), a front radiation detector (122) and a side radiation detector (124), the radiation detectors vertically sliding to vertically scan a standing patient along the vertical scanning direction, the two radiation detectors (122, 124) respectively being two multi-energy counting detectors, 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 (123) and the lateral radiation detector (124), so that the lateral radiation detector (124) at least provides: a first lateral exploration view corresponding to a first portion of energy received by the lateral radiation detector (124) and below a first given energy threshold, referred to as a low energy lateral exploration view, o a second lateral exploration view corresponding to a second portion of energy received by the lateral radiation detector (124) and above a second given energy threshold, referred to as a high energy lateral 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 (21) at different imaging positions along the vertical scanning direction, modulating the intensity of the driving current of the side radiation source (123) along the vertical scanning direction according to the patient's bone thickness, according to the patient's soft tissue thickness and according to the identified specific bone locations at different positions along the vertical scanning direction, (3) a lateral multi-energy image is obtained by performing a single vertical scan on a standing patient along the vertical scanning direction by the lateral radiation source (123) and the lateral radiation detector (124), o Modulating the intensity of the driving current of the side radiation source (123) according to the thickness of the patient's bone, according to the thickness of the patient's soft tissue and according to the identified specific bone location at different positions along the vertical scanning direction, without modulating the intensity of the voltage of the side radiation source (123), which is automatically performed in order to improve the compromise between: ■ the total radiation dose received by the patient during said vertical scan, ■ and for at least one or more or preferably all lateral images given by the lateral radiation detector (124), the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction, The side radiation detector (124) provides at least: a first side image, corresponding to a first portion of the energy received by said side radiation detector (124) and below a first given energy threshold, referred to as a low energy side image, a second side image corresponding to a second portion of the energy received by the side radiation detector (124) and above a second given energy threshold, referred to as a high energy side image, o At least one combined profile image corresponding to a combination of the first profile image and the second profile image.

6. A radiographic imaging method, comprising: Two radiation sources (121, 123) whose imaging directions are orthogonal to each other, a front radiation source (121) and a side radiation source (123), wherein the radiation sources slide vertically so as to vertically scan a standing patient along a vertical scanning direction, Two radiation detectors (122, 124) respectively associated with the two radiation sources (121, 123), a front radiation detector (122) and a side radiation detector (124), the radiation detectors vertically sliding to vertically scan a standing patient along the vertical scanning direction, the two radiation detectors (122, 124) 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 (121, 123) and by the front radiation detector and the side radiation detector (122, 124), so that the front radiation detector and the side radiation detector (122, 124) at least give: a first frontal exploration view corresponding to a first portion of energy received by the frontal radiation detector (122) 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 (122) and above a second given energy threshold, referred to as a high energy frontal exploration view, a first lateral exploration view corresponding to a first portion of energy received by the lateral radiation detector (124) and below a first given energy threshold, referred to as a low energy lateral exploration view, o a second lateral exploration view corresponding to a second portion of energy received by the lateral radiation detector (124) and above a second given energy threshold, referred to as a high energy lateral 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 (21) at different imaging positions along the vertical scanning direction, modulating the intensity of the driving current of both the front radiation source and the side radiation source (121, 123) along the vertical scanning direction according to the patient's bone thickness, according to the patient's soft tissue thickness and according to the identified specific bone locations at different positions along the vertical scanning direction, A frontal multi-energy image is obtained by performing a single vertical scan on a standing patient along the vertical scanning direction by the frontal radiation source (121) and the frontal radiation detector (122), o Modulating the intensity of the driving current of the front radiation source (121) according to the thickness of the patient's bone, according to the thickness of the patient's soft tissue and according to the identified specific bone location at different positions along the vertical scanning direction, without modulating the intensity of the voltage of the front radiation source (121), which is automatically performed in order to improve the compromise between: ■ the total radiation dose received by the patient during said vertical scan, ■ and for at least one or more or preferably all frontal images given by the frontal radiation detector (122), local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction, The front radiation detector (122) provides at least: a first frontal image, corresponding to a first portion of energy received by said frontal radiation detector (122) and below a first given energy threshold, referred to as a low energy frontal image, a second frontal image, corresponding to a second portion of the energy received by the frontal radiation detector (122) and above a second given energy threshold, referred to as a high energy frontal image, o at least one combined frontal image corresponding to a combination of said first frontal image and said second frontal image, and obtaining (3) a lateral multi-energy image by vertically scanning a standing patient along the vertical scanning direction by the lateral radiation source (123) and the lateral radiation detector (124), o Modulating the intensity of the driving current of the side radiation source (123) according to the thickness of the patient's bone, according to the thickness of the patient's soft tissue and according to the identified specific bone location at different positions along the vertical scanning direction, without modulating the intensity of the voltage of the side radiation source (123), which is automatically performed in order 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 at least one or more or preferably all lateral images given by the lateral radiation detector (124), The side radiation detector (124) is configured to provide at least: a first side image, corresponding to a first portion of the energy received by said side radiation detector (124) and below a first given energy threshold, referred to as a low energy side image, a second side image corresponding to a second portion of the energy received by the side radiation detector (124) and above a second given energy threshold, referred to as a high energy side image, o at least one combined profile image corresponding to a combination of the first profile image and the second profile image, Both (3) the frontal multi-energy image and the lateral multi-energy image are obtained during the same vertical scan.

7. The radiographic method according to claims 4 to 6, characterized in that: processing (22) the first front exploration view and the second front exploration view into 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 (22) the first side exploration view and the second side exploration view into a multi-material decomposition having 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.

8. The radiographic method according to any one of the preceding claims, characterized in that: (1) the front single energy exploration view is obtained by performing a single preliminary vertical scan on a standing patient along the vertical scanning direction by the front radiation source (121) and the front radiation detector (122), (1) the lateral single 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 (123) and the lateral radiation detector (124), Both (1) the frontal single-energy probing view and the lateral single-energy probing view are obtained during the same single vertical scan.

9. 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.

10. The radiological imaging method according to claim 9, characterized in that: The first given energy threshold is equal to the second given energy threshold, The front multi-energy image and / or the side multi-energy image are obtained (3), so that the front radiation detector and / or the side radiation detector (122, 124) first gives: ○ the first frontal image, o a third frontal image, corresponding to the total energy received by the frontal radiation detector (122), referred to as the total energy frontal image, ■ obtaining the second frontal image by subtracting the first frontal image from the third frontal image, ○ and / or the first side image, o and / or a third lateral image, which corresponds to the total energy received by said lateral radiation detector (124), referred to as a total energy lateral image, ■ The second lateral image is obtained by subtracting the first lateral image from the third lateral image.

11. The radiographic method according to any one of the preceding claims, characterized in that: The frontal image is obtained by vertically scanning a standing patient along the vertical scanning direction by the frontal radiation source (121) and the frontal radiation detector (122), wherein: o said modulating along said vertical scanning direction the intensity of the driving current of at least said frontal radiation source (121) according to said patient thickness and according to said specific bone positioning at different positions along said vertical scanning direction, The side image is obtained by vertically scanning a standing patient along the vertical scanning direction by the side radiation source (123) and by the side radiation detector (124), wherein: o said modulating the intensity of the driving current of at least said side radiation source (123) along said vertical scanning direction according to said patient thickness and according to said specific bone positioning at different positions along said vertical scanning direction, (3) Both the frontal image and the side image are obtained during the same vertical scan.

12. 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 (121, 123) without modulating the voltage intensity of the front radiation source and / or the side radiation source (121, 123) 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, the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction is not reduced at a given contrast threshold.

13. 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 (121, 123) without modulating the voltage intensity of the front radiation source and / or the side radiation source (121, 123) 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 of the identified specific bone location at different imaging positions along the vertical scanning direction or the ratio of the contrast-to-noise ratio to the square root of the total radiation dose 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.

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

15. The radiographic method according to any one of the preceding claims, characterized in that: For each of the radiation detectors (122, 124): 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 is operable in a time delay and sum mode.

16. 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.

17. The radiographic method according to any one of the preceding claims, characterized in that The method also modulates the driving current intensity of the front radiation source and / or the side radiation source (121, 123) 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.

18. The radiological imaging method according to claim 13, 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.

19. The radiological imaging method according to claim 13 or 14, 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.

20. 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 homogenization of the original radiation after having undergone at least the local image contrast improvement so as to eliminate image artifacts from the drive current intensity modulation, and preferably wherein the front image and / or the side image undergo a contrast enhancement step after having been normalized.

21. 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.

22. 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.

23. 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.

24. 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.

25. The radiological imaging 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.

26. 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.

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 (121, 123) 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 (122, 124) are associated with the two radiation sources (121, 123), respectively. The two radiation detectors (122, 124) 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, the automatic image processing function automatically balances the image density to make the response of the detector uniform.

34. A radiological imaging method according to any one of the preceding claims, characterized in that The two radiation detectors (122, 124) are respectively associated with the two radiation sources (121, 123), and the two radiation detectors (122, 124) 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 voltage intensity of the front radiation source is greater than 90 kVp, or more preferably greater than 100 kVp.

37. 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.

38. A radiological imaging method according to any one of the preceding claims, characterized in that Depending on the patient thickness and / or depending on the patient 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.

39. A radiological imaging method according to any one of the preceding claims, characterized in that: o the second frontal image contains information allowing assessment (7) of the patient's bone density, and the second lateral image contains information allowing assessment (7) of the patient's bone density, ○ and / or the combined frontal image presents the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction, and the local image contrast is sufficient to make a (5) diagnosis to the patient, and the combined lateral image presents the local image contrast of the identified specific bone location at different imaging positions along the vertical scanning direction, and the local image contrast is sufficient to make a (5) diagnosis to the patient.

Images