Radiation imaging method using multi-energy scan images - Patents.com

Abstract

The present invention relates to a radiological imaging method comprising two radiation detectors (122, 124) respectively associated with two radiation sources (121, 123), the radiological imaging method comprising at least one operating mode in which frontal and lateral multi-energy scout views are generated (1) and combined and processed (20) to generate a frontal multi-energy image in order to assess at least the thickness (22) of the patient's bones, at least the thickness (22) of the patient's soft tissues, and the localization (21) of a particular bone of the patient at different imaging positions along the vertical scanning direction. The frontal radiation detector (122) provides at least a first frontal image, called a low-energy frontal image, a second frontal image, called a high-energy frontal image, and at least a combined frontal image corresponding to the combination of the first and second frontal images, and the lateral multi-energy image is generated (3). A lateral radiation detector (124) provides at least a first lateral image, referred to as a low-energy lateral image, a second lateral image, referred to as a high-energy lateral image, and at least a combined lateral image corresponding to a combination of the first and second lateral images, both the frontal multi-energy image and the lateral multi-energy image being produced during the same vertical scan (3).

Description

[Technical field]

[0001] The present invention relates to the technical field of a radiation imaging method and a radiation imaging device for carrying out said radiation imaging method. [Background technology]

[0002] Various types of radiological images can be produced, including: A radiological scan image directed at a full (detailed and complete) view of the patient or one or more of the patient's organs or parts of the patient's organs, used for diagnosis by a specialist; and A radiological scan image directed at the distribution of bone density within a patient, or within one or more of a patient's organs, or within a portion of a patient's organ, used for expert bone density assessment There is.

[0003] The radiological image is preferably an X-ray image.

[0004] To improve the accuracy of diagnosis and / or bone density assessment, in a first step, a scout view is performed, and then using information extracted from this scout view to adapt the imaging parameters, one or more scan images are performed, which are used by a specialist for either diagnosis or bone density assessment.

[0005] The scout view and scan images are performed by vertical scanning of a frontal imaging line including a frontal radiation source and a frontal radiation detector, and / or a lateral imaging line including a lateral radiation source and a lateral radiation detector along the height of a standing patient. The scout view is performed with approximately 1 / 10th the radiation dose compared to the scan image.

[0006] According to the first prior art, when performing a mono-energy scout view following a mono-energy scan image, the imaging parameters are adapted to allow obtaining a good quality diagnostic image, but the imaging parameters cannot give a good result of bone density evaluation, i.e. a good result of bone density evaluation cannot be derived from the diagnostic image. If a bone density evaluation is then also required, not only does a new scan image with different imaging parameters have to be made, but the new scan image may not correspond exactly topologically to the previous scan image, since the standing patient has moved at least a little in the meantime.

[0007] According to the second prior art, when performing a multi-energy scan image, the imaging parameters are adapted to allow obtaining a good quality bone density image, but this imaging parameter cannot give a good result of diagnosis, i.e. a good result of a diagnostic image cannot be derived from this bone density image. Then, if a diagnosis is also required, not only a new scan image with different imaging parameters needs to be made, but this new scan image may not correspond exactly topologically to the previous scan image, since the standing patient has moved at least a little in the meantime. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] European Patent Application No. 16711889 (WO 2017 / 137792) [Patent Document 2] U.S. Patent Application No. 16 / 076660 (U.S. Patent Application Publication No. 2019 / 0046133) [Patent Document 3] European Patent Application Publication No. 17758269 (International Publication No. 2019 / 008407) [Patent Document 4] U.S. Patent Application No. 16 / 628410 (U.S. Patent Application Publication No. 2020 / 0163643) [Patent Document 5] International Publication No. 2021 / 094806 [Non-patent literature]

[0009] [Non-Patent Document 1] Nowak, T., Eberhard, M., Schmidt, B., Frey, D., Distler, O., Saltybaeva, N., ... & Euler, A.,(2021),"Bone mineral density quantification from localizer radiographs: accuracy and precision of energy-integrating detector CT and photon-counting detector CT",Radiology,298(1),147-152 Summary of the Invention [Problem to be solved by the invention]

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

[0011] More specifically, the present invention aims to provide a scan image which can be used for diagnosis with good results and from which partial images can be extracted and further combined in order to simultaneously give good results for bone density assessment. The combination of both partial images leads to an accurate assessment of bone density. Thus, both a good diagnosis and a good bone density assessment can be derived from the same scan image. Moreover, since the diagnosis and a good bone density assessment can be derived from the same image, there is an exact topological correspondence between the diagnosis and the bone density assessment, since the standing patient is in exactly the same position for both. [Means for solving the problem]

[0012] Therefore, to be of good quality and useful for both diagnosis and bone density assessment, radiological imaging methods must: First, a scout view that is either mono-energy or multi-energy, whereas in the prior art, the scout view is only mono-energy; Second, extracted information from the scout view, which is used to perform a multi-energy scan image, which in the prior art is only single energy, and Use.

[0013] A multi-energy scan gives even better results if performed after a multi-energy scout view rather than after a single-energy scout view.

[0014] The multi-energy scan images can be either frontal or lateral images, or can include both frontal and lateral images.

[0015] A first object of the present invention deals with en face multi-energy scan images performed after a en face single energy scout view.

[0016] This first objective is to two radiation sources having mutually orthogonal imaging directions, one frontal radiation source and one lateral radiation source, sliding vertically to perform a vertical scan of a standing patient along a vertical scanning direction; sliding two radiation detectors, one frontal radiation detector and one side radiation detector, respectively associated with the two radiation sources, vertically to perform a vertical scan of a standing patient along the vertical scan direction, where at least the frontal radiation detector is a multi-energy counting detector; This is achieved by a radiation imaging method comprising: wherein the radiation imaging method includes at least one operation mode, and in the at least one operation mode, a frontal mono-energy scout view is created by performing a preliminary vertical scan of a standing patient along the vertical scan direction with the frontal radiation source and the frontal radiation detector; the frontal scout view is processed to identify a patient thickness and a localization of specific bones at different positions along the vertical scanning direction within the frontal scout view; a drive current intensity of at least the frontal radiation source is modulated along the vertical scan direction in response to the identified patient thickness and a localization of the identified particular bone at different positions along the vertical scan direction; As a result, the total radiation dose received by the patient during said vertical scan; local image contrasts of the identified specific bone localizations at different imaging positions along the vertical scanning direction for at least one or more, or preferably all, of the frontal images provided by the frontal radiation detector; with a driving current intensity modulation of the frontal radiation source and without a voltage intensity modulation of the frontal radiation source, depending on the thickness of the patient and depending on the localization of the identified specific bone at different positions along the vertical scan direction, in order to improve the compromise between a frontal multi-energy image is created by performing a single vertical scan of a standing patient along the vertical scan direction with the frontal radiation source and the frontal radiation detector, which is performed automatically; Thereby, the front radiation detector, after the single vertical scan, a first front image, referred to as a low-energy front image, received by the front radiation detector and corresponding to a first portion of energy below a first given energy threshold; a second frontal image, referred to as a high energy frontal image, received by the frontal radiation detector and corresponding to a second portion of energy above a second given energy threshold; at least a combined front image corresponding to a combination of the first front image and the second front image; Gives.

[0017] A second object of the present invention deals with lateral multi-energy scan images performed after the lateral mono-energy scout view.

[0018] This second objective is to two radiation sources having mutually orthogonal imaging directions, one frontal radiation source and one lateral radiation source, sliding vertically to perform a vertical scan of a standing patient along a vertical scanning direction; two radiation detectors, one front radiation detector and one side radiation detector, respectively associated with the two radiation sources, sliding vertically to perform a vertical scan of a standing patient along the vertical scan direction, at least the side radiation detector being a multi-energy counting detector; This is achieved by a radiation imaging method comprising: wherein the radiation imaging method includes at least one operation mode, and in the at least one operation mode, a lateral mono-energy scout view is created by performing a preliminary vertical scan of a standing patient along the vertical scan direction with the lateral radiation source and the lateral radiation detector; the lateral scout view is processed to identify a patient thickness and a localization of specific bones at different positions along the vertical scanning direction within the lateral scout view; a drive current intensity of at least the side radiation source is modulated along the vertical scan direction in response to a patient thickness and a localization of the identified particular bone at different positions along the vertical scan direction; As a result, the total radiation dose received by the patient during said vertical scan; local image contrasts of the identified specific bone localizations at different imaging positions along the vertical scanning direction for at least one or more, or preferably all, lateral images provided by the lateral radiation detectors; with a drive current intensity modulation of the side radiation source and without a voltage intensity modulation of the side radiation source, depending on a patient thickness and depending on a localization of the identified specific bone at different positions along the vertical scan direction, in order to improve the compromise between a lateral multi-energy image is created by performing a single vertical scan of a standing patient along the vertical scan direction with the lateral radiation source and the lateral radiation detector, which is performed automatically; Thereby, the side radiation detector, after the single vertical scan, at least a first side image, referred to as a low-energy side image, received by the side radiation detector and corresponding to a first portion of energy below a first given energy threshold; a second lateral image, referred to as a high energy lateral image, received by the lateral radiation detector and corresponding to a second portion of energy above a second given energy threshold; at least a combined side image corresponding to a combination of the first side image and the second side image; Gives.

[0019] A third object of the present invention deals with both frontal and lateral multi-energy scan images performed after both frontal and lateral mono-energy scout views.

[0020] This third objective is to two radiation sources having mutually orthogonal imaging directions, one frontal radiation source and one lateral radiation source, sliding vertically to perform a vertical scan of a standing patient along a vertical scanning direction; two radiation detectors, one front radiation detector and one side radiation detector, respectively associated with the two radiation sources, sliding vertically to perform a vertical scan of a standing patient along the vertical scan direction, the two radiation detectors being two multi-energy counting detectors respectively; This is achieved by a radiation imaging method comprising: wherein the radiation imaging method includes at least one operation mode, and in the at least one operation mode, a frontal mono-energy scout view and a lateral mono-energy scout view are generated by performing a preliminary vertical scan of a standing patient along the vertical scan direction with the frontal and lateral radiation sources and the frontal and lateral radiation detectors; the frontal and lateral scout views are processed to identify a patient thickness and localization of specific bones at different positions along the vertical scanning direction within the frontal and lateral scout views; a drive current intensity of both the front radiation source and the side radiation source is modulated along the vertical scan direction in response to a patient thickness and a localization of the identified specific bone at different positions along the vertical scan direction; As a result, the total radiation dose received by the patient during said vertical scan; local image contrasts of the identified specific bone localizations at different imaging positions along the vertical scanning direction for at least one or more, or preferably all, of the frontal images provided by the frontal radiation detector; with a drive current intensity modulation of the frontal radiation source and without a voltage intensity modulation of the frontal radiation source, depending on a patient thickness and depending on a localization of the identified specific bone at different positions along the vertical scan direction, in order to improve the compromise between a frontal multi-energy image is created by performing a single vertical scan of a standing patient along the vertical scan direction with the frontal radiation source and the frontal radiation detector, which is performed automatically; Thereby, the front radiation detector, after the single vertical scan, a first front image, referred to as a low-energy front image, received by the front radiation detector and corresponding to a first portion of energy below a first given energy threshold; a second frontal image, referred to as a high energy frontal image, received by the frontal radiation detector and corresponding to a second portion of energy above a second given energy threshold; at least a combined front image corresponding to a combination of the first front image and the second front image; Given As a result, the total radiation dose received by the patient during said vertical scan; local image contrasts of the identified specific bone localizations at different imaging positions along the vertical scanning direction for at least one or more, or preferably all, lateral images provided by the lateral radiation detectors; with a drive current intensity modulation of the side radiation source and without a voltage intensity modulation of the side radiation source, depending on a patient thickness and depending on a localization of the identified specific bone at different positions along the vertical scan direction, in order to improve the compromise between a lateral multi-energy image is generated by performing a single vertical scan of a standing patient along the vertical scan direction with the lateral radiation source and the lateral radiation detector; Thereby, the side radiation detector comprises at least a first side image, referred to as a low-energy side image, received by the side radiation detector and corresponding to a first portion of energy below a first given energy threshold; a second lateral image, referred to as a high energy lateral image, received by the lateral radiation detector and corresponding to a second portion of energy above a second given energy threshold; at least a combined side image corresponding to a combination of the first side image and the second side image; Given Both frontal and lateral multi-energy images are produced during the same vertical scan.

[0021] A fourth object of the present invention deals with en face multi-energy scan images performed after the en face multi-energy scout view.

[0022] This fourth objective is: two radiation sources having mutually orthogonal imaging directions, one frontal radiation source and one lateral radiation source, sliding vertically to perform a vertical scan of a standing patient along a vertical scanning direction; two radiation detectors, one front radiation detector and one side radiation detector, respectively associated with the two radiation sources, sliding vertically to perform a vertical scan of a standing patient along the vertical scan direction, the two radiation detectors being two multi-energy counting detectors respectively; This is achieved by a radiation imaging method comprising: wherein the radiation imaging method includes at least one operation mode, and in the at least one operation mode, A frontal multi-energy scout view is created by performing a preliminary vertical scan of a standing patient along the vertical scan direction with the frontal radiation source and the frontal radiation detector, whereby the frontal radiation detector detects at least: a first frontal scout view, referred to as a low-energy frontal scout view, received by the frontal radiation detector and corresponding to a first portion of energy below a first given energy threshold; a second frontal scout view, referred to as a high energy frontal scout view, corresponding to a second portion of the energy received by the frontal radiation detector that is above a second given energy threshold; Given The first frontal scout view and the second frontal scout view At least the patient's bone thickness and At least the thickness of the patient's soft tissue; Localizing specific bones of the patient at different imaging positions along the vertical scan direction; are combined and processed to evaluate a drive current intensity of the frontal radiation source is modulated along the vertical scan direction in response to a thickness of the patient, a thickness of the patient's soft tissue, and a localization of the identified specific bone at different positions along the vertical scan direction; As a result, the total radiation dose received by the patient during said vertical scan; local image contrasts of the identified specific bone localizations at different imaging positions along the vertical scanning direction for at least one or more, or preferably all, of the frontal images provided by the frontal radiation detector; in accordance with a thickness of the patient's bones, in accordance with a thickness of the patient's soft tissues, and in accordance with a localization of the identified specific bones at different positions along the vertical scan direction, with a drive current intensity modulation of the frontal radiation source and without a voltage intensity modulation of the frontal radiation source, a frontal multi-energy image is created by performing a single vertical scan of a standing patient along the vertical scan direction with the frontal radiation source and the frontal radiation detector, which is performed automatically; Thereby, the front radiation detector, after the single vertical scan, a first front image, referred to as a low-energy front image, received by the front radiation detector and corresponding to a first portion of energy below a first given energy threshold; a second frontal image, referred to as a high energy frontal image, received by the frontal radiation detector and corresponding to a second portion of energy above a second given energy threshold; at least a combined front image corresponding to a combination of the first front image and the second front image; Gives.

[0023] A fifth object of the present invention deals with lateral multi-energy scan images performed after a lateral multi-energy scout view.

[0024] This fifth objective is: two radiation sources having mutually orthogonal imaging directions, one frontal radiation source and one lateral radiation source, sliding vertically to perform a vertical scan of a standing patient along a vertical scanning direction; two radiation detectors, one front radiation detector and one side radiation detector, respectively associated with the two radiation sources, sliding vertically to perform a vertical scan of a standing patient along the vertical scan direction, the two radiation detectors being two multi-energy counting detectors respectively; This is achieved by a radiation imaging method comprising: wherein the radiation imaging method includes at least one operation mode, and in the at least one operation mode, A lateral multi-energy scout view is created by performing a preliminary vertical scan of a standing patient along the vertical scan direction with the lateral radiation source and the lateral radiation detector, whereby the lateral radiation detector detects at least: a first side scout view, referred to as a low energy side scout view, received by the side radiation detector and corresponding to a first portion of energy below a first given energy threshold; a second side scout view, referred to as a high energy side scout view, corresponding to a second portion of the energy received by the side radiation detector that is above a second given energy threshold; Given The first side scout view and the second side scout view At least the patient's bone thickness and At least the thickness of the patient's soft tissue; Localizing specific bones of the patient at different imaging positions along the vertical scan direction; are combined and processed to evaluate a drive current intensity of the side radiation source is modulated along the vertical scan direction in response to a thickness of the patient, a thickness of the patient's soft tissue, and a localization of the identified particular bone at different positions along the vertical scan direction; As a result, the total radiation dose received by the patient during said vertical scan; local image contrasts of the identified specific bone localizations at different imaging positions along the vertical scanning direction for at least one or more, or preferably all, lateral images provided by the lateral radiation detectors; in accordance with a thickness of the patient's bones, in accordance with a thickness of the patient's soft tissues, and in accordance with a localization of the identified specific bones at different positions along the vertical scan direction, with a drive current intensity modulation of the side radiation source and without a voltage intensity modulation of the side radiation source, a lateral multi-energy image is created by performing a single vertical scan of a standing patient along the vertical scan direction with the lateral radiation source and the lateral radiation detector, which is performed automatically; Thereby, the side radiation detector, after the single vertical scan, at least a first side image, referred to as a low-energy side image, received by the side radiation detector and corresponding to a first portion of energy below a first given energy threshold; a second lateral image, referred to as a high energy lateral image, received by the lateral radiation detector and corresponding to a second portion of energy above a second given energy threshold; at least a combined side image corresponding to a combination of the first side image and the second side image; Gives.

[0025] A sixth object of the present invention deals with both frontal and lateral multi-energy scan images performed after both frontal and lateral multi-energy scout views.

[0026] This sixth objective is: two radiation sources having mutually orthogonal imaging directions, one frontal radiation source and one lateral radiation source, sliding vertically to perform a vertical scan of a standing patient along a vertical scanning direction; two radiation detectors, one front radiation detector and one side radiation detector, respectively associated with the two radiation sources, sliding vertically to perform a vertical scan of a standing patient along the vertical scan direction, the two radiation detectors being two multi-energy counting detectors respectively; This is achieved by a radiation imaging method comprising: wherein the radiation imaging method includes at least one operation mode, and in the at least one operation mode, A frontal multi-energy scout view and a lateral multi-energy scout view are generated by performing a preliminary vertical scan of a standing patient along the vertical scan direction with the frontal and lateral radiation sources and the frontal and lateral radiation detectors, whereby the frontal and lateral radiation detectors detect at least: a first frontal scout view, referred to as a low-energy frontal scout view, received by the frontal radiation detector and corresponding to a first portion of energy below a first given energy threshold; a second frontal scout view, referred to as a high energy frontal scout view, corresponding to a second portion of the energy received by the frontal radiation detector that is above a second given energy threshold; a first side scout view, referred to as a low energy side scout view, received by the side radiation detector and corresponding to a first portion of energy below a first given energy threshold; a second side scout view, referred to as a high energy side scout view, corresponding to a second portion of the energy received by the side radiation detector that is above a second given energy threshold; Given the first front scout view and the first side scout view and the second front scout view and the second side scout view; At least the patient's bone thickness and At least the thickness of the patient's soft tissue; Localizing specific bones of the patient at different imaging positions along the vertical scan direction; are combined and processed to evaluate a drive current intensity of both the front radiation source and the side radiation source is modulated along the vertical scan direction in response to a thickness of the patient, a thickness of the patient's soft tissue, and a localization of the identified specific bone at different positions along the vertical scan direction; As a result, the total radiation dose received by the patient during said vertical scan; local image contrasts of the identified specific bone localizations at different imaging positions along the vertical scanning direction for at least one or more, or preferably all, of the frontal images provided by the frontal radiation detector; in accordance with a thickness of the patient's bones, in accordance with a thickness of the patient's soft tissues, and in accordance with a localization of the identified specific bones at different positions along the vertical scan direction, with a drive current intensity modulation of the frontal radiation source and without a voltage intensity modulation of the frontal radiation source, a frontal multi-energy image is created by performing a single vertical scan of a standing patient along the vertical scan direction with the frontal radiation source and the frontal radiation detector, which is performed automatically; Thereby, the front radiation detector, after the single vertical scan, a first front image, referred to as a low-energy front image, received by the front radiation detector and corresponding to a first portion of energy below a first given energy threshold; a second frontal image, referred to as a high energy frontal image, received by the frontal radiation detector and corresponding to a second portion of energy above a second given energy threshold; at least a combined front image corresponding to a combination of the first front image and the second front image; Given As a result, the total radiation dose received by the patient during said vertical scan; local image contrasts of the identified specific bone localizations at different imaging positions along the vertical scanning direction for at least one or more, or preferably all, lateral images provided by the lateral radiation detectors; with a drive current intensity modulation of the side radiation source and without a voltage intensity modulation of the side radiation source, and depending on the thickness of the patient's bone, the thickness of the patient's soft tissue, and the localization of the identified specific bone at different positions along the vertical scan direction, performing a vertical scan of a standing patient along the vertical scan direction with the lateral radiation source and the lateral radiation detector to generate a lateral multi-energy image, which is performed automatically; Thereby, the side radiation detector comprises at least a first side image, referred to as a low-energy side image, received by the side radiation detector and corresponding to a first portion of energy below a first given energy threshold; a second lateral image, referred to as a high energy lateral image, received by the lateral radiation detector and corresponding to a second portion of energy above a second given energy threshold; at least a combined side image corresponding to a combination of the first side image and the second side image; Given Both frontal and lateral multi-energy images are produced during the same vertical scan.

[0027] The present invention covers not only the above-listed radiographic imaging methods but also radiographic imaging apparatuses for implementing each of these radiographic imaging methods.

[0028] For all the foregoing purposes of the present invention, unless stated to the contrary, a combined image (front, side or both) corresponding to a combination of the first image and the second image means only that this combined image is equal to the result of the combination of the first image and the second image, and does not mean that it was obtained as such. A detector can, for example, directly provide the combined image and the second image, and then the first image is obtained by subtracting the second image from the combined image.

[0029] Preferred embodiments include one or more of the following features which can be taken separately or together, in partial or complete combination with any of the aforementioned objects of the invention.

[0030] Preferably, the first and second frontal scout views are processed into a multi-material decomposition having at least two material thickness vertical profiles; Preferably, bimaterial decomposition between Al and PMMA or HA (hydroxyapatite) and H 2 It is processed into one of two materials decomposed between o, and / or the first and second side scout views are processed into a multi-material decomposition having at least two material thickness normal vectors; Preferably, a bimaterial decomposition between Al and PMMA, or between HA and H 2 O is processed into one of two materials decomposed.

[0031] Indeed, on the one hand, Al or HA show X-ray attenuation properties close to those of human bone, while on the other hand, PMMA or H 2 O exhibits X-ray attenuation characteristics similar to those of human soft tissue.

[0032] Preferably, the frontal mono-energy scout view is created by performing a single preliminary vertical scan of a standing patient along the vertical scan direction with the frontal radiation source and the frontal radiation detector; the lateral mono-energy scout view is created by performing a single preliminary vertical scan of a standing patient along the vertical scan direction with the lateral radiation source and the lateral radiation detector; Both the frontal mono-energy scout view and the lateral mono-energy scout view are made during the same single vertical scan.

[0033] Thus, because the frontal and lateral scout views are both performed simultaneously during the same single vertical scan, and the standing patient does not move between them, the frontal and lateral scout views correspond exactly to one another topologically.

[0034] Preferably, said first given energy threshold is less than or equal to said second given energy threshold, and preferably equal to said second given energy threshold.

[0035] Thus, in both cases the full range of energy thresholds is covered, with the second case being less costly.

[0036] Preferably, 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 by the front radiation detector and / or the side radiation detector, The first front image, a third front image, called a total energy front image, corresponding to the total energy received by the front radiation detector, the second front image being obtained by subtracting the first front image from the third front image; and / or said first side image, and / or a third lateral image, called a total energy lateral image, corresponding to the total energy received by the lateral radiation detector, the second lateral image being obtained by subtracting the first lateral image from the third lateral image. is created to give the first

[0037] Thus, the total energy image and the high energy image can be provided directly by the detector, and the low energy image can be obtained by simple subtraction by subtracting the high energy image from the total energy image.

[0038] Preferably, the frontal image is produced by performing a vertical scan of a standing patient along the vertical scan direction with the frontal radiation source and the frontal radiation detector; the modulation of the drive current intensity of at least the frontal radiation source along the vertical scanning direction is dependent on a thickness of the patient and on a localization of the particular bone at different positions along the vertical scanning direction; the lateral image is produced by performing a vertical scan of a standing patient along the vertical scan direction with the lateral radiation source and the lateral radiation detector; the modulation of the drive current intensity of at least the side radiation source along the vertical scanning direction is dependent on a thickness of the patient and on a localization of the particular bone at different positions along the vertical scanning direction; The front and side images are produced during the same vertical scan.

[0039] Thus, since the frontal and lateral images are both performed simultaneously during the same vertical scan, and the standing patient does not move in between, the frontal and lateral images correspond exactly to each other topologically.

[0040] Preferably, The driving current intensity modulation of the front radiation source and / or the side radiation source is reducing the overall radiation dose received by a patient during said vertical scan; For lateral and / or frontal images, for all or a portion of the patient thickness along said vertical scanning direction, the local image contrast of said identified bone localizations at different imaging positions along the same said vertical scanning direction is not reduced below a given contrast threshold. In order to improve the compromise between the above, it is automatically performed without voltage intensity modulation of the front radiation source and / or the side radiation source.

[0041] This means that It is possible to aim for the lowest possible overall radiation dose whilst maintaining the correct prescribed image quality; or improving image quality without unduly increasing overall radiation dose; or even further, that the margin provided by the present invention can be distributed in part to reduce radiation dose and in part to maintain a given image quality. means.

[0042] Preferably, The driving current intensity modulation of the front radiation source and / or the side radiation source is reducing the overall radiation dose received by a patient during said vertical scan; Improving the contrast-to-noise ratio, or the ratio between the contrast-to-noise ratio and the square root of the total radiation dose of the identified specific bone localization at different imaging positions along the vertical scan direction, for the frontal and / or lateral images, for all or part of the patient thickness along the vertical scan image, with the same total radiation dose but without drive current intensity modulation, for local image contrast of the identified specific bone localization at different imaging positions along the vertical scan direction; In order to improve the compromise between the above, it is automatically performed without voltage intensity modulation of the front radiation source and / or the side radiation source.

[0043] This means that It is possible to aim for the lowest possible overall radiation dose whilst maintaining a given good image quality; or that it is possible to significantly improve image quality without increasing the overall radiation dose; or even further, that the margin provided by the present invention can be distributed in part to reduce radiation dose and in part to maintain a given better image quality. means.

[0044] Preferably, The en face multi-energy image acquisition may include acquiring at least two energy bins, or at least three energy bins, or at least six energy bins. and / or at most 20 energy bins, or at most 15 energy bins, or at most 10 energy bins This is carried out using and / or the lateral multi-energy image acquisition includes at least two energy bins, or at least three energy bins, or at least six energy bins. and / or at most 20 energy bins, or at most 15 energy bins, or at most 10 energy bins This is performed using

[0045] Thus, a larger number of bins allows different tissue textures within a patient to be more accurately distinguished from one another, but at the expense of increased system complexity and the risk of less signal being available in each bin.

[0046] Preferably, For each said radiation detector, the pixel size of the radiation detector is in the range of 50 μm to 250 μm, alternatively in the range of 80 μm to 150 μm, alternatively about 100 μm; and / or the overall height of the radiation detector is in the range of 0.1 cm to 1.2 cm, or in the range of 0.2 cm to 1.0 cm, or in the range of 0.3 cm to 0.7 cm; and / or the overall width of the radiation detector is in the range of 10 cm to 80 cm, or in the range of 20 cm to 70 cm, or in the range of 30 cm to 60 cm; And / or, the radiation detector may be operated in a time delay and sum mode.

[0047] Thus, the image resolution is improved without creating too many artifacts and the entire effective width of the patient can be covered.

[0048] Preferably, said identified specific bone localization comprises the patient's spine, preferably is the patient's spine.

[0049] Indeed, the patient's spine is the particular bony localization that is the most interesting to analyze in detail within the patient's body for orthopedic imaging purposes and is therefore used to drive the current intensity modulation.

[0050] Alternatively, the specific bone localization could be the pelvis, arms, or legs of a standing patient along a vertical scan direction, depending on the region of interest within the portion of the patient's body that is imaged.

[0051] Preferably, the drive current intensity modulation of the front radiation source and / or the side radiation source is also performed to reach a signal-to-noise ratio value for the front image and / or the side image that is constant and common to a majority of the imaging positions along the vertical scanning direction, preferably to all the imaging positions along the vertical scanning direction, but which can take two different values ​​for the front image and the side image, respectively.

[0052] Preferably, for each of said frontal and / or lateral images, said signal to noise ratio value is constant and pre-determined for each different patient organ being imaged.

[0053] Preferably, 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, the operator of the radiographic imaging method preferably having the possibility, via a manual command, to deviate from the 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, said standard signal-to-noise ratio value corresponds to a number of X-ray photons received per detector pixel comprised between 20 and 40, the operator of the radiographic imaging method preferably having the possibility, via a manual command, to deviate from the standard value by at least -25% or +100%, more preferably by at least -50% or +200%.

[0054] Therefore, with a constant optimized signal-to-noise ratio along or along the entire vertical scan direction, the local image contrast of identified specific bones at different imaging positions along the vertical scan direction is significantly improved with respect to what was actually the region of interest in the frontal and / or lateral images.

[0055] Preferably, the front and / or lateral images, after having undergone at least the local image contrast improvement, are normalized by homogenization of the raw radiation to remove image artifacts resulting from the drive current intensity modulation, and preferably, the front and / or lateral images, after having been normalized, are subjected to a contrast enhancement step.

[0056] In fact, due to this drive modulation, some artifacts were present in the frontal and / or lateral images, which overlapped with some modulation patterns of light and dark grey levels on the images, making the interpretation of these images a little difficult for the operator of the radiological imaging method.

[0057] Preferably, the localization of said identified specific bones excludes, if any, metallic prostheses, e.g. of parts of the skeleton of the patient's body, or metallic parts, e.g. metallic protective gear, which have been worn on the patient's body prior to performing said radiographic imaging method.

[0058] Indeed, these (for the patient) foreign bodies introduced in or on the patient's body may lead to a bad optimization of the emitted dose, since they are metallic and therefore stop much more radiation (X-rays) than the rest of the patient's body, and at the heights corresponding to these foreign bodies there is a risk of leading to an overexposure to the emitted radiation. If the driving voltage strength is constant, and if the metallic outliers are not excluded, more or all parameters will be selected for the maximum thickness, leading to the emission of a higher or much higher radiation dose than required, which may lead to a worse outcome, since it would be very harmful for the patient.

[0059] Preferably, the current intensity modulation is maximized so as to also maximize the vertical scan velocity at a constant value.

[0060] Thus, for a given amount of radiation emitted and therefore received by a standing patient during said vertical scan, both are kept at the same level, and the total vertical scan time is significantly reduced, which has the advantage of reducing the possibility of and the effects of movement of a standing patient, thereby somewhat reducing the risk of blurring and distortion of the frontal and lateral images.

[0061] Preferably, said operational mode can be manually turned on or off by an operator of the radiological imaging method.

[0062] Thus, a very advantageous method of operating a radiological imaging device is available, which can be cancelled if an operator of said radiological imaging device wants to get rid of it, for example to operate said radiological imaging device fully manually.The radiological imaging method according to an advantageous embodiment of the invention presents three operating modes, namely a fully manual mode, an AEC mode without modulation (AEC=Automatic Exposure Control) and an AEC mode with modulation.

[0063] Preferably, the operating mode can be used for patient morphology types ranging from pediatric to obese adults, is dedicated to vertical scanning of large and / or obese patients, and / or the operating mode is dedicated to vertical scanning of pediatric patients.

[0064] The radiographic imaging method according to the invention is even more interesting when the patient's thickness may be particularly thin or particularly thicker than that of an average-sized patient. This shows that the radiographic imaging method according to the invention is very patient-specific and takes into account a wide attenuation range in long axis imaging. Of course, the radiographic imaging method according to the invention also works very well for standard-sized patients.

[0065] Preferably, said 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.

[0066] Thus, the radiation imaging method according to the invention can be carried out with relatively simple and inexpensive radiation sources having relatively slow current intensity drive capabilities.

[0067] Preferably, said current intensity modulation is in the range of at least 20mA to 300mA, preferably in the range of 10mA to 400mA.

[0068] The radiation imaging method according to the invention can also be carried out with relatively simple and inexpensive radiation sources that have a relatively limited range of current intensity modulation capabilities.

[0069] Preferably, the vertical scan speed is in the range of at least 8 cm / sec to 20 cm / sec, preferably in the range of 0.4 cm / sec to 35 cm / sec.

[0070] Thus, the radiation imaging method according to the present invention can be implemented with relatively simple and inexpensive radiation sources having a relatively limited range of vertical scan speed capabilities, while at the same time making full use of the available range of vertical scan speed capabilities.

[0071] Preferably, each of the frontal scout views and / or lateral scout views is created by performing a preparatory vertical scan of a standing patient along a vertical scan direction with a reduced overall radiation dose compared to each of the frontal and lateral images prior to creating each of the frontal and lateral images, preferably the reduced overall radiation is less than 10% of the overall radiation dose, more preferably less than 5% of the overall radiation dose.

[0072] Thus, depending on the thickness profile and the localization of certain bones of the patient's standing body along the vertical scan direction, the modulation of the drive current intensity, and possibly also the modulation of the vertical scan speed, can be determined immediately before performing the vertical scan, which results in effective frontal and lateral images of the standing patient's body, performed with a limited but complete radiation dose sufficient to create high-quality frontal and lateral images. The scout view can be performed at the expense of a very limited overexposure to the emitted radiation. The benefit can even be twofold, not only is the overexposure during the scout view execution (+10% or +5%) very limited, but it is also very efficient to optimize the compromise between the total radiation dose received and the enhancement of the image contrast.

[0073] Preferably, pixels in said scout view are collected by zones of NxN pixels, more preferably ranging from 2x2 pixels to 10x10 pixels, to create imaging zones.

[0074] Thus, the image quality and image contrast of the scout view is improved, despite the very low levels of emitted radiation dose used to perform this scout view.

[0075] Preferably, the images or imaging zones are processed to identify corner points which are then used to calculate the thickness profile and to identify the localization of the particular bone in a standing patient along the vertical scan direction.

[0076] Therefore, despite the very low level of emitted radiation dose, from the scout view it is easier and more efficient to calculate the thickness profile and identify the localization of the specific bones in a standing patient along the vertical scan direction.

[0077] Preferably, said images or said imaging zones are processed by a neural network to calculate said thickness profile and to identify the localization of said particular bones in a standing patient along said vertical scan direction.

[0078] Therefore, it is easier and more efficient to identify the localization of said particular bone in a standing patient along the vertical scanning direction from the scout view, despite the very low level of emitted radiation dose.

[0079] Preferably, the two radiation sources slide vertically to perform a vertical scan of the pelvis or spine or whole body of a standing patient along a vertical scanning direction.

[0080] Preferably, the two radiation detectors are associated with the two radiation sources respectively, and the two radiation detectors are two Photon Counting Detectors (PCDs), each associated with an automatic image processing function that automatically balances the image density whatever the amount of radiation received at the sensitive surface of the radiation detector in order to homogenize the detector response.

[0081] This is an interesting feature since it is difficult for an operator of a radiological imaging method to manually correctly assess over-exposure or under-exposure to the radiation signal emitted by the radiation source. Photon-counting detectors offer improved linearity and signal-to-noise ratio compared to gas detectors.

[0082] Preferably, the two radiation detectors are associated with the two radiation sources respectively, and the two radiation detectors are two multi-energy counting detectors, preferably two Energy Resolved Photon Counting Detectors (ERPCDs).

[0083] Preferably, the radiation is X-ray.

[0084] A standing patient or a patient in a standing position is a patient in a weight-bearing position, as opposed to a lying patient or a patient in a lying position as in computed tomography. Another weight-bearing position instead of a standing patient is a patient in a sitting position.

[0085] Preferably, the voltage strength of the front radiation source is above 90 kVp, or more preferably above 100 kVp.

[0086] Therefore, it becomes easier to distinguish between bone and soft tissue within the patient.

[0087] Preferably, the second energy threshold is selected 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 selected between 50 keV and 90 keV, preferably between 60 keV and 80 keV, more preferably the second energy threshold is selected at 70 keV.

[0088] Thus, even if the patient's broad chest is still accurately seen, the narrow arms or legs are not at all or substantially sacrificed by being unsaturated or very slightly saturated, i.e., overexposed due to system limitations.

[0089] Preferably, the first energy threshold and / or the second energy threshold are varied and / or associated spectral filtering, preferably k-edge filtering, is used and adjusted depending on the thickness of the patient and / or the localization of a particular bone of the patient at different imaging positions along the vertical scan direction.

[0090] Thus, the accuracy of the end-user images used by the professionals is further improved.

[0091] Preferably, the second frontal image includes information that allows one to assess a bone density of the patient, and the second lateral image includes information that allows one to assess a bone density of the patient; And / or the combined frontal image shows local image contrast of the identified specific bone localization at different imaging positions along the vertical scanning direction sufficient to perform a patient diagnosis, and the combined lateral image shows local image contrast of the identified specific bone localization at different imaging positions along the vertical scanning direction sufficient to perform a patient diagnosis.

[0092] Thus, in one overall operation, two different types of images are performed, leading to two different useful applications by the expert.

[0093] To all the above mentioned objects of the present invention and / or to all the above mentioned combinations, one may add either mechanical cross-scatter correction with vertical gaps as described, for example, in EP Application No. 16711889 or US Application No. 16 / 076660, and / or software cross-scatter correction as described, for example, in EP Application No. 17758269 or US Application No. 16628410.

[0094] Preferably, the multi-energy image is a dual-energy image.

[0095] Further features 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, in which: [Brief description of the drawings]

[0096] [Figure 1] FIG. 13 illustrates an example of an imaging workflow of a radiological imaging method according to an embodiment of the present invention with current modulation but without voltage modulation. [Diagram 2]2A-2C illustrate examples of multi-energy scout view acquisition steps within a radiation imaging method according to an embodiment of the present invention and / or multi-energy scan image acquisition steps within a radiation imaging method according to an embodiment of the present invention. [Diagram 3] FIG. 2 illustrates another example of a multi-energy scout view acquisition step within a radiation imaging method according to an embodiment of the present invention and / or a multi-energy scan image acquisition step within a radiation imaging method according to an embodiment of the present invention. [Figure 4] FIG. 13 illustrates an example of a bone localization calculation step with profile of interest extraction within a radiological imaging method according to an embodiment of the present invention. [Diagram 5] 4A-4C illustrate examples of part 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. [Figure 6] FIG. 2 illustrates a first example of another part of a total patient thickness calculation step within a radiation imaging method according to an embodiment of the present invention. [Figure 7] FIG. 2 shows a second example of another part of the calculation step of the thickness of the patient's bones and soft tissues within a radiation imaging method according to an embodiment of the present invention. [Figure 8] FIG. 13 shows an example of a frontal patient mono-energy diagnostic image without the additional possibility of obtaining a good quality bone density distribution image calculation, without an embodiment of the present invention. [Figure 9] FIG. 13 shows an example of a frontal patient multi-energy (dual-energy) image according to an embodiment of the present invention, which is an additional possibility to obtain the calculation of a good quality bone density distribution image. [Figure 10] FIG. 9 shows a zoom of the chest region of FIG. 8. [Figure 11] FIG. 10 shows a zoom of the chest region of FIG. [Figure 12] 4A-4C illustrate an example of the execution of a bone density calculation step within a radiological imaging method according to an embodiment of the present invention. [Figure 13] FIG. 13 shows an example of successive image transformations during application of a bone density calculation step within a radiographic imaging method according to an embodiment of the invention as in FIG. 12. [Figure 14] FIG. 13 shows an example of a table comparing bone density values ​​between a DXA image not according to an embodiment of the present invention, without the additional possibility of obtaining a good quality diagnosis, and a bone density image according to an embodiment of the present invention, with the additional possibility of obtaining a good quality diagnosis calculation. [Figure 15] 1A and 1B are diagrams illustrating examples of the structure of an imaging device for implementing a radiation imaging method according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0097] In the following description, without any contrary mention, what is said about the frontal scout view or the frontal image can be applied equally to the lateral scout view or the lateral image, respectively, and vice versa. Everything that is done for both the frontal scout view and the lateral scout view can be done only for the frontal scout view or the lateral scout view, if only the frontal scout view or the lateral scout view is of interest to the specialist or the patient. Everything that is done for both the frontal image and the lateral image can be done only for the frontal image or the lateral image, if only the frontal image or the lateral image is of interest to the specialist or the patient. When a profile is mentioned, without any contrary mention, a sequence of several partial or regional average values ​​(average values ​​per zone or organ, e.g. average values ​​per leg, pelvis, spine, neck, head or parts thereof) or possibly a single average value may be sufficient, but the result may be less accurate or less precise.

[0098] FIG. 1 shows an example of an imaging workflow of a radiological imaging method according to an embodiment of the invention with current modulation but without voltage modulation.

[0099] In a first alternative, multi-energy images, or even dual-energy images, are performed based on a single-energy scout view acquisition.

[0100] First, step 1 of acquiring a frontal scout view and a side scout view is performed.

[0101] A step 20 of thickness profile extraction is then performed from the frontal and lateral scout views performed in the acquisition step 1. This step 20 includes a sub-step 21 of bone localization calculation with extraction of a profile of interest along the patient height, which is performed simultaneously in parallel with a sub-step 22 of patient thickness calculation, the patient thickness profile along the patient height is then processed by extraction of thickness values ​​along the profile of interest coordinates. At the end of the thickness profile extraction step 20, the patient thickness profile along the patient height is available for the next step, which is a determination and selection step 23. The patient thickness profile along the patient height corresponds to the total thickness including both the patient's bone thickness and the patient's soft tissue thickness along the patient height.

[0102] Then, a step 23 of determining fixed voltage values ​​(in kV) and spectral filters, and of selecting detector energy thresholds, from a model and / or look-up table 24 containing a catalogue of models and / or references, based on the patient thickness profile along the patient height. The model and / or look-up table 24 provides an exposure target 25 corresponding to the model or reference selected in the determining and selecting step 24. At the end of the determining and selecting step 23, the spectral filtering, fixed voltage values, one or more detector energy thresholds are available for the next calculation step 26.

[0103] A calculation step 26 then performs the calculation of the acquisition speed of the vertical scan along the height of the standing (or sitting) patient and the current modulation profile along the height of the patient. The calculation step 26 also uses the exposure target 25. The calculation step also performs a feedback loop towards the decision and selection step 24. At the end of the calculation step 26, the spectral filtering, the fixed voltage value, the detector energy threshold(s), the vertical scan acquisition speed (in mm / sec), the current modulation profile along the height of the patient in mA are available for the next image acquisition step 3. The current modulation profile along the height of the patient as well as other parameters are also directly available to the image normalization step 4 and the bone density calculation step 7.

[0104] In this calculation step 26, a calculation of the acquisition speed of the vertical scan along the height of the standing (or sitting) patient and the current modulation profile along the height of the patient is performed, the selection strategy of the current profile and vertical scan speed for a given voltage value is similar to the strategy used in WO 2021 / 094806 (incorporated herein by reference) and can be summarized as follows: Calculation of the exposure budget (the product of the current and exposure time required to reach the exposure target); Maximizing vertical scan speed given the available tube current budget (constrained by hardware specifications in terms of maximum tube power and maximum instantaneous current value); Calculation of the corresponding current profile therefrom It is.

[0105] Parameters

number

number

[0106] The exposure time t is given by the highest current value that can be used for a given current value, taking into account tube power limitations and lower and upper current limits. The acquisition speed is selected (either as a free value or from a set of allowable system speeds) as the smallest speed among those calculated along the thickness profile. The current value is then updated to match the target signal given this fixed acquisition speed.

[0107] Whenever the current value falls below the current boundary by more than the current boundary, the voltage may be lowered or raised, respectively, to bring it back into the acceptable range of values ​​until the voltage value reaches its lower and / or upper limit. Matching the target signal has priority over maintaining an optimal voltage value, and this priority is met by virtue of this feedback loop from step 26 to step 23 (see FIG. 1).

[0108] Once the optimal exposure parameters are selected, their profile along the slot scan can be further adapted to hardware constraints (e.g., in the slope of the current and voltage profiles) if these constraints have not already been taken into account in the previous step. The exposure parameters can then be formatted into a file readable by the system to perform image acquisition step 3 (see FIG. 1).

[0109] All steps 20 , 23 , 24 , 25 , 26 are part of the exposure parameter calculation routine 2 .

[0110] Then, after this exposure parameter calculation routine 2 is fully completed, an image acquisition step 3 is performed based on the spectral filtering, fixed voltage values, one or more detector energy thresholds, vertical scan acquisition speed (in mm / sec), and current modulation profile (in mA) along the patient height. This acquired image is a multi-energy image, here 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.

[0111] Based on the multi-energy images and the current intensity modulation profile acquired in acquisition step 3, the acquired frontal and lateral images are then normalized in normalization step 4. The normalized frontal and lateral images can then be processed to some extent (using post-processing steps) in diagnostic image processing chain step 5 to give the expert good quality images for diagnosing the patient, and then displayed on a screen to be viewed by the expert.

[0112] The diagnostic image processing chain 5 corresponds to the standard image processing chain normally used in single-energy image acquisition, but is applied to a combination of low-energy and high-energy normalized images, ie the sum of low-energy and high-energy images.

[0113] Then, based on the multi-energy images acquired in acquisition step 3, the current intensity modulation profile and other available parameters, the acquired frontal and lateral images are further processed in another way (using other post-processing steps) in bone density calculation step 7 to provide the expert with a bone density calculation distribution which can also be displayed to the expert.

[0114] In a second alternative, a multi-energy image, and further here a dual-energy image, is performed based on a multi-energy, and further still dual-energy, scout view acquisition.

[0115] First, step 1 of acquiring a frontal scout view and a side scout view is performed.

[0116] A step 20 of thickness profile extraction is then performed from the frontal and lateral scout views performed in the acquisition step 1. This step 20 includes a sub-step 21 of bone localization calculation with extraction of a profile of interest along the height of the patient, which is performed simultaneously in parallel with a sub-step 22 of calculation of both the patient's bone thickness and the patient's soft tissue thickness, and then both the patient's bone thickness profile and the patient's soft tissue thickness profile along the height of the patient are processed by extraction of the respective thickness values ​​along the profile of interest coordinates. In sub-step 21, coordinates {x_i}(x_1,x_2...x_N) corresponding to the localization of points in the profile of interest are extracted from the scout views. In sub-step 22, a conversion between signal and thickness is performed, which results in a bone thickness image fBone and a soft tissue thickness image fSoft. The combined result of sub-steps 21 and 22 is a collection of {fBone(x_i)} and {fSoft(x_i)}.

[0117] At the end of the thickness profile extraction step 20, both the patient's bone thickness profile and the patient's soft tissue thickness profile along the patient's height are available for the next step, which is the determination and selection step 23.

[0118] Then, a step 23 of determining fixed voltage values ​​(in kV) and spectral filters and of selecting detector energy thresholds from a model and / or look-up table 24 containing a catalogue of models and / or references is based on the patient's bone thickness profile along the patient's height and the patient's soft tissue thickness profile. The model and / or look-up table 24 provides an exposure target 25 corresponding to the model or reference selected in the determining and selecting step 23. At the end of the determining and selecting step 23, the spectral filtering, fixed voltage values, detector energy threshold(s) are available for the next calculation step 26.

[0119] A calculation step 26 then calculates the acquisition speed of the vertical scan along the height of the standing (or sitting) patient and the current modulation profile along the height of the patient. The calculation step 26 also uses the exposure target 25. The calculation step also performs a feedback loop towards the decision and selection step 24. At the end of the calculation step 26, the spectral filtering, the fixed voltage value, the detector energy threshold(s), the vertical scan acquisition speed (in mm / sec), the current modulation profile along the height of the patient in mA are available for the next image acquisition step 3. The current modulation profile along the height of the patient is also directly available to the image normalization step 4 and the bone density calculation step 7.

[0120] In this calculation step 26, a calculation of the acquisition speed of the vertical scan along the height of the standing (or sitting) patient and the current modulation profile along the height of the patient is performed, the selection strategy of the current profile and vertical scan speed for a given voltage value is similar to the strategy used in WO 2021 / 094806 (incorporated herein by reference) and can be summarized as follows: Calculation of the exposure budget (the current needed to reach the exposure target multiplied by the exposure time); Maximizing vertical scan speed given an available tube current budget (constrained by hardware specifications in terms of minimum and maximum tube power and minimum and maximum instantaneous current values); Calculation of the corresponding current profile therefrom It is.

[0121] Parameters

number

number

[0122] The exposure time t is given by the highest current value that can be used for a given current value, taking into account tube power limitations and lower and upper current limits. The acquisition speed is selected (either as a free value or from a set of allowable system speeds) as the smallest speed among those calculated along the thickness profile. The current value is then updated to match the target signal given this fixed acquisition speed.

[0123] Whenever the current value falls below the current boundary by more than the current boundary, the voltage may be lowered or raised, respectively, to bring it back into the acceptable range of values ​​until the voltage value reaches its lower and / or upper limit. Matching the target signal has priority over maintaining an optimal voltage value, and this priority is met by virtue of this feedback loop from step 26 to step 23 (see FIG. 1).

[0124] Once the optimal exposure parameters are selected, their profile along the slot scan can be further adapted to hardware constraints (e.g., in the slope of the current and voltage profiles) if these constraints have not already been taken into account in the previous step. The exposure parameters can then be formatted into a file readable by the system to perform image acquisition step 3 (see FIG. 1).

[0125] All steps 20 , 23 , 24 , 25 , 26 are part of the exposure parameter calculation routine 2 .

[0126] Then, after this exposure parameter calculation routine 2 is fully completed, an image acquisition step 3 is performed based on the spectral filtering, fixed voltage values, one or more detector energy thresholds, vertical scan acquisition speed (in mm / sec), and current modulation profile (in mA) along the patient height. This acquired image is a multi-energy image and also a dual-energy image. The acquired image can include a frontal image and / or a lateral image. The acquired image preferably includes a frontal image and a lateral image.

[0127] Then, based on the multi-energy image acquired in acquisition step 3, the current intensity modulation profile, and other available parameters, the acquired frontal and lateral images are normalized in normalization step 4. The normalized frontal and lateral images are then processed to some extent (using post-processing steps) in diagnostic image processing chain step 5 to provide the specialist with images of quality for diagnosing the patient, which can then be displayed on a screen to be viewed by the specialist.

[0128] The diagnostic image processing chain 5 corresponds to the standard image processing chain normally used in single-energy image acquisition, but is applied to a combination of low-energy and high-energy normalized images, ie the sum of low-energy and high-energy images.

[0129] Then, based on the multi-energy images, current intensity modulation profile and other available parameters acquired in acquisition step 3, the acquired frontal and lateral images are further processed in another manner (using other post-processing steps) to provide the expert with a bone density calculation distribution that can also be displayed to the expert.

[0130] FIG. 2 illustrates an example of a multi-energy scout view acquisition step within a radiological imaging method according to an embodiment of the present invention and / or a multi-energy scan image acquisition step within a radiological imaging method according to an embodiment of the present invention.

[0131] In the multi-energy scout view acquisition step 1 in FIG. 1, the normalized attenuation spectrum AS is represented as a function of the energy E expressed in keV.

[0132] In the multi-energy scout view mode, the detector directly reads the low-energy and high-energy scout views and infers the full-energy scout view by summing the high-energy and low-energy scout views.

[0133] In mono-energy or single-energy scout view mode, there is only a single bin corresponding to all energy bins.

[0134] In the multi-energy image acquisition step 3 in FIG. 1, the normalized attenuation spectrum AS is expressed as a function of the energy E expressed in keV.

[0135] In multi-energy image acquisition, the detector reads the low-energy and high-energy images directly and infers the full-energy image by adding the high-energy and low-energy images together.

[0136] FIG. 3 illustrates another example of a multi-energy scout view acquisition step within a radiological imaging method according to an embodiment of the present invention and / or a multi-energy scan image acquisition step within a radiological imaging method according to an embodiment of the present invention.

[0137] In the multi-energy scout view acquisition step 1 in FIG. 1, the attenuation spectrum AS is represented as a function of the energy E expressed in keV.

[0138] In the multi-energy scout view mode, the detector reads the full-energy scout view and the high-energy scout view, and infers the low-energy scout view by subtracting the high-energy scout view from the full-energy scout view.

[0139] In mono-energy or single-energy scout view mode, there is only a single bin corresponding to all energy bins.

[0140] In the multi-energy image acquisition step 3 in FIG. 1, the attenuation spectrum AS is expressed as a function of the energy E expressed in keV.

[0141] In multi-energy image acquisition, the detector reads a full-energy image and a high-energy image, and infers the low-energy image by subtracting the high-energy image from the full-energy image.

[0142] FIG. 4 shows an example of a bone localization calculation step with profile of interest extraction within a radiological imaging method according to an embodiment of the present invention.

[0143] In FIG. 4 there is a scout view 6, here a lateral scout view 6, with corner points 60 positioned along a lateral image 6 of the patient's skeleton, the corner points 60 representing the localization of particular bones of the patient at various imaging positions along the vertical scanning direction, which here is also the height of a standing patient.

[0144] These corner points 60 represent curves extracted from the patient's lateral image 6 by summarizing detector signal values ​​at anatomical landmarks of clinical interest along the slot scan. Several processing techniques can therefore be used, which can be based on landmark extraction from image filtering and segmentation techniques, or machine learning techniques.

[0145] This is how sub-step 21 of the bone localization calculation is performed.

[0146] FIG. 5 shows an example of a part 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.

[0147] In the first alternative, the multi-energy case, the sub-step 22 of calculating both the patient thickness and the soft tissue thickness is performed each time by the online operation 222 of the online thickness calculation 222 in FIG. 7 using information obtained separately offline by the offline operation 221 of the offline signal-to-thickness mapping calibration in FIG. 5 .

[0148] In the offline operation 221 of the offline signal-to-thickness mapping calibration, the scout exposure parameters 2211 and the known material thickness 2212 are used as inputs to a measurement or simulation 2213 that gives as output a measured or simulated detector signal 2214. Both the known material thickness 2212 and the measured or simulated detector signal 2214 are then 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, look-up tables (LUTs) or model fits. In contrast to the single energy scout view where the mapping is based on the total energy signal, the multi-energy scout view mapping, here the dual energy scout view, is based on signal pairs including both low and high energy signals, along with the calculation of one mapping per material, i.e., soft tissue for the low energy signal and bone for the high energy. The thickness of the PMMA is stored in the high and low energy coordinate systems. The Al thickness is stored in the high and low energy coordinate systems.

[0149] In the second alternative, the single energy case, the sub-step 22 of calculating the patient thickness is performed each time by the online operation 223 of the online thickness calculation 223 in FIG. 6 using information separately obtained offline by the offline operation 221 of the offline signal-to-thickness mapping calibration in FIG. 5 .

[0150] In the offline operation 221 of the offline signal-to-thickness mapping calibration, the scout exposure parameters 2211 and the known material thickness 2212 are used as inputs to a measurement or simulation 2213 that gives as output a measured or simulated detector signal 2214. Both the known material thickness 2212 and the measured or simulated detector signal 2214 are then 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, look-up tables (LUTs) or model fits. For single energy scout views, the mappings are based on the total energy signal corresponding to the total signal, along with the calculation of one mapping of the total thickness of one material, i.e., soft tissue. The thickness of the PMMA is stored in high and low energy coordinate systems.

[0151] FIG. 6 shows a first example of another part of a total patient thickness calculation step within a radiological imaging method according to an embodiment of the invention, which is performed at the start of a monoenergetic case.

[0152] In the online operation 223 of the online thickness calculation, the measured detection signal 2231 is used as an input to a simplified database 2232, or a portion 2232 of the database 2215, that stores a signal vs. PMMA thickness (corresponding to total thickness) mapping. The database 2232 that stores the signal vs. PMMA thickness mapping provides as output the total thickness 2233 of the patient.

[0153] FIG. 7 shows a second example of another part of a patient's bone and soft tissue thickness calculation step within a radiological imaging method according to an embodiment of the present invention.

[0154] In the online operation 222 of the online thickness calculation, the measured detector signal 2221 is used as input to both a sub-database storing signal to bone thickness mappings 2222 and a sub-database storing signal to soft tissue thickness mappings 2224. The sub-database storing signal to bone thickness mappings 2222 provides as output the bone thickness 2223. The sub-database storing signal to soft tissue thickness mappings 2224 provides as output the soft tissue thickness 2225.

[0155] 8 shows an example of a frontal patient mono-energy diagnostic image without the additional possibility of obtaining a good quality bone density distribution image calculation, without an embodiment of the present invention. Good quality frontal diagnostic image 80 with thoracic region 81 showing the patient's spine.

[0156] 9 shows an example of a frontal patient multi-energy (dual-energy) image according to an embodiment of the present invention, which provides an additional possibility for obtaining a good quality bone density distribution image calculation. A good quality frontal diagnostic image 90 with a thoracic region 91 showing the patient's spine.

[0157] Figure 10 shows a zoom of the chest region of Figure 8. The chest region 81 is represented by a good quality diagnostic en face image derived from an acquired en face image from which no additional calculation of good quality bone density distribution can be derived.

[0158] Figure 11 shows a zoom of the chest region of Figure 9. The chest region 91 is represented by a good quality diagnostic en face image derived from the acquired en face image from which additional calculations of good quality bone density distribution can be derived.

[0159] FIG. 12 illustrates an example of the implementation of a bone density calculation step within a radiological imaging method according to an embodiment of the present invention.

[0160] FIG. 13 shows an example of successive image transformations during application of a bone density calculation step within a radiographic imaging method according to an embodiment of the invention as in FIG.

[0161] Referring to FIG. 1, a bone density calculation 7 may be performed after the multi-energy image acquisition step 3 .

[0162] The spectral filtering, fixed voltage values, one or more detector energy thresholds, vertical scan acquisition speed (in mm / sec), current modulation profile (in mA) along the patient height, and the calibrated signal-to-thickness mapping of database 2215 (in FIG. 5 ) are available to a base calculation sub-step 71 of the patient's two material thicknesses to first convert images 73 and 74, which are low-energy and high-energy images acquired after the multiple-energy acquisition step 3, into images 75 and 76, which are Al and PMMA images.

[0163] Then, by using the offline calibrated model 70, these Al and PMMA images 75 and 76 are converted and combined into a BMD image 77 (bone mineral density image, also referred to simply as bone density image) by sub-step 72, which is conversion to bone mineral density.

[0164] FIG. 14 shows an example of a table comparing bone density values ​​between a DXA image not according to an embodiment of the present invention, with no additional possibility of obtaining a good quality diagnosis, and a bone density image according to an embodiment of the present invention, with the additional possibility of obtaining a good quality diagnosis calculation.

[0165] DXA columns 101, 102, and 103, corresponding to low, intermediate, and high bone density, respectively, are taken from the prior art paper "Nowak, T., Eberhard, M., Schmidt, B., Frey, D., Distler, O., Saltybaeva, N., ... & Euler, A., (2021) "Bone mineral density quantification from localizer radiographs: accuracy and precision of energy-integrating detector CT and photon-counting detector CT", Radiology, 298(1), 147-152". Values ​​are measured in the European Spine Phantom (ESP).

[0166] The bone mineral density images produced by the embodiments of the present invention are at least as good as, and in some cases somewhat better than, this prior art "Nowak et al. (2021)" as can be seen from "inventive columns" 111, 112, 113 corresponding to low, intermediate, and high bone density, respectively, by comparing with DXA columns 101, 102, 103. Moreover, the multi-energy images acquired in step 3 according to the embodiments of the present invention allow additionally to derive good quality diagnostic images that could not be made by this prior art "Nowak et al. (2021)".

[0167] Multi-energy image acquisition according to an embodiment of the present invention includes: Derivation of good quality images and Derivation of good quality bone mineral density images and whereas prior art processes are only capable of deriving one of these two types of images, and are not capable of deriving both such types of images from the same image acquisition step.

[0168] Fig. 15 shows an example of the structure of an imaging device for implementing a radiation imaging method according to an embodiment of the present invention. The vertical scan direction is orthogonal to the plane of Fig. 15. The patient height is also orthogonal to the plane of Fig. 15. The vertical scan direction is the patient height scan direction, and therefore the scan direction along the patient height for a standing patient.

[0169] An imaging apparatus or device 129 is present.

[0170] The frontal emission and reception line includes a frontal tube 121 which emits a frontal beam of X-rays 125 which passes through the patient's body (not shown here but located within an intersection zone 128 ) and reaches a frontal detector 122 .

[0171] The side emission and reception line includes a side tube 123 which emits an X-ray side beam 126 that passes through the patient's body (not shown here but located within an intersection zone 128 ) and reaches a side detector 124 .

[0172] To avoid cross-scatter in the intersection zone 128, mechanical correction due to vertical gaps between the front emission and reception lines and the side emission and reception lines, and / or software cross-scatter correction between the front emission and reception lines and the side emission and reception lines can be used, as described above.

[0173] The invention has been described with reference to preferred embodiments, however, many variations are possible within the scope of the invention. [Explanation of symbols]

[0174] 6 Side image, side scout view 7 Bone density calculation 24 Models and / or Reference Tables 25 Exposure Target 60 Corner Points 70 Offline calibrated models 73 images 74 images 75 images 76 images 77 BMD Images 80 Frontal diagnostic images 81 Chest area 90 Frontal diagnostic images 91 Chest area 101 DXA column 102 DXA column 103 DXA column 111 Column of the Invention 112 Column of the Invention 113 Column of the Invention 121 Front tube 122 Front detector 123 Side pipe 124 Side Detector 125 X-ray front beam 126 X-ray side beam 128 Intersection Zone 129 Imaging equipment or imaging device 221 Offline operation 222 Online thickness calculation 223 Online thickness calculation 2211 Scout Exposure Parameters 2212 known material thickness 2213 Measurement or Simulation 2214 Measured or Simulated Detector Signal 2215 Signal to Thickness Mapping Database 2221 Measured detector signal 2222 Subdatabase 2223 Bone Thickness 2224 Subdatabase 2225 Soft tissue thickness 2231 Measured detector signal 2232 Simplified database, part of database 2215 2233 Total thickness of patient

Claims

1. A radiation imaging method, comprising: two radiation sources (121, 123) having mutually orthogonal imaging directions, one frontal radiation source (121) and one lateral radiation source (123), sliding vertically to perform a vertical scan of a standing patient along a vertical scanning direction; two radiation detectors (122, 124), one frontal radiation detector (122) and one lateral radiation detector (124), respectively associated with the two radiation sources (121, 123), sliding vertically to perform a vertical scan of a standing patient along the vertical scan direction, at least the frontal radiation detector (122) being a multi-energy counting detector; Including, The radiation imaging method includes at least one mode of operation, the at least one mode of operation comprising: a frontal mono-energy scout view is created by performing a preliminary vertical scan of a standing patient along the vertical scan direction with the frontal radiation source (121) and the frontal radiation detector (122) (1); The frontal scout view is processed (20) to identify a patient thickness (22) and a localization (21) of specific bones at different positions along the vertical scanning direction within the frontal scout view; a drive current intensity of at least the frontal radiation source (121) is modulated along the vertical scan direction in response to the identified patient thickness and to a localization of the identified particular bone at different positions along the vertical scan direction; As a result, the total radiation dose received by the patient during said vertical scan; local image contrasts of the identified specific bone localizations at different imaging positions along the vertical scanning direction for at least one or more, or preferably all, of the frontal images provided by the frontal radiation detector (122); with a drive current intensity modulation of the frontal radiation source (121) and without a voltage intensity modulation of the frontal radiation source (121), depending on the thickness of the patient and depending on the localization of the identified specific bone at different positions along the vertical scan direction, in order to improve the compromise between a frontal multi-energy image is created (3) by performing a single vertical scan of a standing patient along the vertical scan direction with the frontal radiation source (121) and the frontal radiation detector (122), which is performed automatically; Thereby, the front radiation detector (122) detects at least a first front image, referred to as a low-energy front image, received by the front radiation detector (122) and corresponding to a first portion of energy below a first given energy threshold; a second frontal image, referred to as a high-energy frontal image, received by the frontal radiation detector (122) and corresponding to a second portion of energy above a second given energy threshold; and at least a combined front image corresponding to a combination of the first front image and the second front image; The radiation imaging method provides:

2. A radiation imaging method, comprising: two radiation sources (121, 123) having mutually orthogonal imaging directions, one frontal radiation source (121) and one lateral radiation source (123), sliding vertically to perform a vertical scan of a standing patient along a vertical scanning direction; two radiation detectors (122, 124), one front radiation detector (122) and one side radiation detector (124), respectively associated with the two radiation sources (121, 123), sliding vertically to perform a vertical scan of a standing patient along the vertical scan direction, at least the side radiation detector (124) being a multi-energy counting detector; Including, The radiation imaging method includes at least one mode of operation, the at least one mode of operation comprising: A lateral mono-energy scout view is created (1) by performing a preliminary vertical scan of a standing patient along the vertical scan direction with the lateral radiation source (123) and the lateral radiation detector (124); The lateral scout view is processed (20) to identify a patient thickness (22) and a localization (21) of specific bones at different positions along the vertical scanning direction within the lateral scout view; a drive current intensity of at least the side radiation source (123) is modulated along the vertical scan direction in response to the identified patient thickness and a localization of the identified particular bone at different positions along the vertical scan direction; As a result, the total radiation dose received by the patient during said vertical scan; local image contrast of the identified specific bone localization at different imaging positions along the vertical scan direction for at least one or more, or preferably all, of the lateral images provided by the lateral radiation detector (124); with drive current intensity modulation of the side radiation source (123) and without voltage intensity modulation of the side radiation source (123), depending on the thickness of the patient and depending on the localization of the identified specific bone at different positions along the vertical scan direction, in order to improve the compromise between a lateral multi-energy image is created (3) by performing a single vertical scan of the standing patient along the vertical scan direction with the lateral radiation source (123) and the lateral radiation detector (124), which is performed automatically; Thereby, the side radiation detector (124) detects at least a first side image, referred to as a low-energy side image, received by the side radiation detector (124) and corresponding to a first portion of energy below a first given energy threshold; a second lateral image, referred to as a high-energy lateral image, received by the lateral radiation detector (124) and corresponding to a second portion of energy above a second given energy threshold; and at least a combined side image corresponding to a combination of the first side image and the second side image; The radiation imaging method provides:

3. A radiation imaging method, comprising: two radiation sources (121, 123) having mutually orthogonal imaging directions, one frontal radiation source (121) and one lateral radiation source (123), sliding vertically to perform a vertical scan of a standing patient along a vertical scanning direction; two radiation detectors (122, 124), one front radiation detector (122) and one side radiation detector (124), respectively associated with the two radiation sources (121, 123), slide vertically to perform a vertical scan of a standing patient along the vertical scan direction, the two radiation detectors (122, 124) being two multi-energy counting detectors respectively; Including, The radiation imaging method includes at least one mode of operation, the at least one mode of operation comprising: frontal and lateral mono-energy scout views are generated (1) by performing a preliminary vertical scan of a standing patient along the vertical scan direction with the frontal and lateral radiation sources (121) and (123) and the frontal and lateral radiation detectors (122) and (124); The frontal and lateral scout views are processed (20) to identify a patient thickness (22) and a localization (21) of specific bones at different positions along the vertical scanning direction within the frontal and lateral scout views; a drive current intensity of both the front radiation source (121) and the side radiation source (123) is modulated along the vertical scan direction in response to the identified patient thickness and a localization of the identified particular bone at different positions along the vertical scan direction; As a result, the total radiation dose received by the patient during said vertical scan; local image contrasts of the identified specific bone localizations at different imaging positions along the vertical scanning direction for at least one or more, or preferably all, of the frontal images provided by the frontal radiation detector (122); with a drive current intensity modulation of the frontal radiation source (121) and without a voltage intensity modulation of the frontal radiation source (121), depending on the thickness of the patient and depending on the localization of the identified specific bone at different positions along the vertical scan direction, in order to improve the compromise between a frontal multi-energy image is created (3) by performing a single vertical scan of a standing patient along the vertical scan direction with the frontal radiation source (121) and the frontal radiation detector (122), which is performed automatically; Thereby, the front radiation detector (122) detects at least a first front image, referred to as a low-energy front image, received by the front radiation detector (122) and corresponding to a first portion of energy below a first given energy threshold; a second frontal image, referred to as a high-energy frontal image, received by the frontal radiation detector (122) and corresponding to a second portion of energy above a second given energy threshold; and at least a combined front image corresponding to a combination of the first front image and the second front image; Given And, thereby, the total radiation dose received by the patient during said vertical scan; local image contrast of the identified specific bone localization at different imaging positions along the vertical scan direction for at least one or more, or preferably all, of the lateral images provided by the lateral radiation detector (124); with drive current intensity modulation of the side radiation source (123) and without voltage intensity modulation of the side radiation source (123), depending on the thickness of the patient and depending on the localization of the identified specific bone at different positions along the vertical scan direction, in order to improve the compromise between a lateral multi-energy image is created (3) by performing a single vertical scan of the standing patient along the vertical scan direction with the lateral radiation source (123) and the lateral radiation detector (124), which is performed automatically; Thereby, the side radiation detector (124) includes at least a first side image, referred to as a low-energy side image, received by the side radiation detector (124) and corresponding to a first portion of energy below a first given energy threshold; a second lateral image, referred to as a high-energy lateral image, received by the lateral radiation detector (124) and corresponding to a second portion of energy above a second given energy threshold; and at least a combined side image corresponding to a combination of the first side image and the second side image; Given A radiological imaging method in which both frontal and lateral multi-energy images are produced during the same vertical scan (3).

4. A radiation imaging method, comprising: two radiation sources (121, 123) having mutually orthogonal imaging directions, one frontal radiation source (121) and one lateral radiation source (123), sliding vertically to perform a vertical scan of a standing patient along a vertical scanning direction; two radiation detectors (122, 124), one front radiation detector (122) and one side radiation detector (124), respectively associated with the two radiation sources (121, 123), slide vertically to perform a vertical scan of a standing patient along the vertical scan direction, the two radiation detectors (122, 124) being two multi-energy counting detectors respectively; Including, The radiation imaging method includes at least one mode of operation, the at least one mode of operation comprising: A frontal multi-energy scout view is created (1) by performing a preliminary vertical scan of a standing patient along the vertical scan direction with the frontal radiation source (121) and the frontal radiation detector (122), whereby the frontal radiation detector (122) detects at least a first frontal scout view, referred to as a low-energy frontal scout view, received by the frontal radiation detector (122) and corresponding to a first portion of energy below a first given energy threshold; a second frontal scout view, referred to as a high energy frontal scout view, corresponding to a second portion of the energy received by the frontal radiation detector (122) that is above a second given energy threshold; Given The first frontal scout view and the second frontal scout view At least the patient's bone thickness (22) and at least the thickness of the patient's soft tissue (22); localization (21) of specific bones of the patient at different imaging positions along the vertical scan direction; (20) are combined and processed to evaluate a drive current intensity of the frontal radiation source (121) is modulated along the vertical scan direction in response to a thickness of the patient's bones, a thickness of the patient's soft tissue, and a localization of the identified specific bones at different positions along the vertical scan direction; As a result, the total radiation dose received by the patient during said vertical scan; local image contrasts of the identified specific bone localizations at different imaging positions along the vertical scanning direction for at least one or more, or preferably all, of the frontal images provided by the frontal radiation detector (122); with drive current intensity modulation of the frontal radiation source (121) and without voltage intensity modulation of the frontal radiation source (121), depending on the bone thickness of the patient, depending on the thickness of the soft tissue of the patient, and depending on the localization of the identified specific bone at different positions along the vertical scan direction, a frontal multi-energy image is created (3) by performing a single vertical scan of a standing patient along the vertical scan direction with the frontal radiation source (121) and the frontal radiation detector (122), which is performed automatically; Thereby, the front radiation detector (122) detects at least a first front image, referred to as a low-energy front image, received by the front radiation detector (122) and corresponding to a first portion of energy below a first given energy threshold; a second frontal image, referred to as a high-energy frontal image, received by the frontal radiation detector (122) and corresponding to a second portion of energy above a second given energy threshold; and at least a combined front image corresponding to a combination of the first front image and the second front image; The radiation imaging method provides:

5. A radiation imaging method, comprising: two radiation sources (121, 123) having mutually orthogonal imaging directions, one frontal radiation source (121) and one lateral radiation source (123), sliding vertically to perform a vertical scan of a standing patient along a vertical scanning direction; two radiation detectors (122, 124), one front radiation detector (122) and one side radiation detector (124), respectively associated with the two radiation sources (121, 123), slide vertically to perform a vertical scan of a standing patient along the vertical scan direction, the two radiation detectors (122, 124) being two multi-energy counting detectors respectively; Including, The radiation imaging method includes at least one mode of operation, the at least one mode of operation comprising: A lateral multi-energy scout view is created (1) by performing a preliminary vertical scan of a standing patient along the vertical scan direction with the lateral radiation source (123) and the lateral radiation detector (124), whereby the lateral radiation detector (124) detects at least: a first side scout view, referred to as a low-energy side scout view, received by the side radiation detector (124) and corresponding to a first portion of energy below a first given energy threshold; a second side scout view, referred to as a high energy side scout view, received by the side radiation detector (124) and corresponding to a second portion of the energy above a second given energy threshold; Given The first side scout view and the second side scout view At least the patient's bone thickness (22) and at least the thickness of the patient's soft tissue (22); localization (21) of specific bones of the patient at different imaging positions along the vertical scan direction; (20) are combined and processed to evaluate a drive current intensity of the side radiation source (123) is modulated along the vertical scan direction in response to a thickness of the patient's bone, a thickness of the patient's soft tissue, and a localization of the identified particular bone at different positions along the vertical scan direction; As a result, the total radiation dose received by the patient during said vertical scan; local image contrast of the identified specific bone localization at different imaging positions along the vertical scan direction for at least one or more, or preferably all, of the lateral images provided by the lateral radiation detector (124); with drive current intensity modulation of the side radiation source (123) and without voltage intensity modulation of the side radiation source (123), depending on the thickness of the patient's bones, depending on the thickness of the patient's soft tissues, and depending on the localization of the identified specific bones at different positions along the vertical scan direction, a lateral multi-energy image is created (3) by performing a single vertical scan of the standing patient along the vertical scan direction with the lateral radiation source (123) and the lateral radiation detector (124), which is performed automatically; Thereby, the side radiation detector (124) detects at least a first side image, referred to as a low-energy side image, received by the side radiation detector (124) and corresponding to a first portion of energy below a first given energy threshold; a second lateral image, referred to as a high-energy lateral image, received by the lateral radiation detector (124) and corresponding to a second portion of energy above a second given energy threshold; and at least a combined side image corresponding to a combination of the first side image and the second side image; The radiation imaging method provides:

6. A radiation imaging method, comprising: two radiation sources (121, 123) having mutually orthogonal imaging directions, one frontal radiation source (121) and one lateral radiation source (123), sliding vertically to perform a vertical scan of a standing patient along a vertical scanning direction; two radiation detectors (122, 124), one front radiation detector (122) and one side radiation detector (124), respectively associated with the two radiation sources (121, 123), slide vertically to perform a vertical scan of a standing patient along the vertical scan direction, the two radiation detectors (122, 124) being two multi-energy counting detectors respectively; Including, The radiation imaging method includes at least one mode of operation, the at least one mode of operation comprising: A frontal multi-energy scout view and a lateral multi-energy scout view are generated (1) by performing a preliminary vertical scan of a standing patient along the vertical scan direction with the frontal radiation source (121) and the lateral radiation source (123) and the frontal radiation detector (122) and the lateral radiation detector (124), whereby the frontal radiation detector (122) and the lateral radiation detector (124) detect at least: a first frontal scout view, referred to as a low-energy frontal scout view, received by the frontal radiation detector (122) and corresponding to a first portion of energy below a first given energy threshold; a second frontal scout view, referred to as a high energy frontal scout view, received by the frontal radiation detector (122) and corresponding to a second portion of the energy above a second given energy threshold; a first side scout view, referred to as a low-energy side scout view, received by the side radiation detector (124) and corresponding to a first portion of energy below a first given energy threshold; a second side scout view, referred to as a high energy side scout view, received by the side radiation detector (124) and corresponding to a second portion of the energy above a second given energy threshold; Given the first front scout view and the first side scout view and the second front scout view and the second side scout view; At least the patient's bone thickness (22) and at least the thickness of the patient's soft tissue (22); localization (21) of specific bones of the patient at different imaging positions along the vertical scan direction; (20) are combined and processed to evaluate a drive current intensity of both the front radiation source (121) and the side radiation source (123) is modulated along the vertical scan direction in response to a thickness of the patient's bones, a thickness of the patient's soft tissue, and a localization of the identified specific bones at different positions along the vertical scan direction; As a result, the total radiation dose received by the patient during said vertical scan; local image contrasts of the identified specific bone localizations at different imaging positions along the vertical scanning direction for at least one or more, or preferably all, of the frontal images provided by the frontal radiation detector (122); with drive current intensity modulation of the frontal radiation source (121) and without voltage intensity modulation of the frontal radiation source (121), depending on the bone thickness of the patient, depending on the thickness of the soft tissue of the patient, and depending on the localization of the identified specific bone at different positions along the vertical scan direction, a frontal multi-energy image is created by performing a single vertical scan of a standing patient along the vertical scan direction with the frontal radiation source (121) and the frontal radiation detector (122), which is performed automatically; Thereby, the front radiation detector (122) detects at least a first front image, referred to as a low-energy front image, received by the front radiation detector (122) and corresponding to a first portion of energy below a first given energy threshold; a second frontal image, referred to as a high-energy frontal image, received by the frontal radiation detector (122) and corresponding to a second portion of energy above a second given energy threshold; and at least a combined front image corresponding to a combination of the first front image and the second front image; Given And, thereby, the total radiation dose received by the patient during said vertical scan; local image contrast of the identified specific bone localization at different imaging positions along the vertical scan direction for at least one or more, or preferably all, of the lateral images provided by the lateral radiation detector (124); with drive current intensity modulation of the side radiation source (123) and without voltage intensity modulation of the side radiation source (123), depending on the thickness of the patient's bones, depending on the thickness of the patient's soft tissues, and depending on the localization of the identified specific bones at different positions along the vertical scan direction, a lateral multi-energy image is created (3) by performing a vertical scan of the standing patient along the vertical scan direction with the lateral radiation source (123) and the lateral radiation detector (124), which is performed automatically; Thereby, the side radiation detector (124) includes at least a first side image, referred to as a low-energy side image, received by the side radiation detector (124) and corresponding to a first portion of energy below a first given energy threshold; a second lateral image, referred to as a high-energy lateral image, received by the lateral radiation detector (124) and corresponding to a second portion of energy above a second given energy threshold; and at least a combined side image corresponding to a combination of the first side image and the second side image; Given A radiological imaging method in which both frontal and lateral multi-energy images are produced during the same vertical scan (3).

7. the first frontal scout view and the second frontal scout view are processed (22) into a multi-material decomposition having at least two material thickness vertical profiles; Preferably, a bimaterial decomposition between Al and PMMA, or between HA and H 2 It is processed into one of two materials decomposed between o, and / or the first side scout view and the second side scout view are processed (22) into a multi-material decomposition having at least two material thickness normal vectors; Preferably, a bimaterial decomposition between Al and PMMA, or between HA and H 2 It is processed into one of two materials decomposed between O, 7. A radiation imaging method according to claim 4.

8. the frontal mono-energy scout view is created by performing a single preliminary vertical scan of a standing patient along the vertical scan direction with the frontal radiation source (121) and the frontal radiation detector (122) (1); the lateral mono-energy scout view is created by performing a single preliminary vertical scan of a standing patient along the vertical scan direction with the lateral radiation source (123) and the lateral radiation detector (124); 8. A method of radiological imaging according to claim 1, wherein both the frontal mono-energy scout view and the lateral mono-energy scout view are produced during the same single vertical scan (1).

9. 9. A radiation imaging method according to any one of the preceding claims, wherein the first given energy threshold is less than or equal to the second given energy threshold, and preferably equal to the second given energy threshold.

10. the first given energy threshold is equal to the second given energy threshold; The front radiation detector (122) and / or the side radiation detector (124) The first front image, a third front image, called a total energy front image, corresponding to the total energy received by the front radiation detector (122), the second front image being obtained by subtracting the first front image from the third front image; and / or said first side image, and / or a third lateral image, called a total energy lateral image, corresponding to the total energy received by the lateral radiation detector (124), the second lateral image being obtained by subtracting the first lateral image from the third lateral image.

10. The method of claim 9, wherein the frontal and / or lateral multi-energy images are generated (3) so as to initially provide:

11. the frontal image is created by performing a vertical scan of a standing patient along the vertical scan direction by the frontal radiation source (121) and the frontal radiation detector (122); said modulation of the drive current intensity of at least said frontal radiation source (121) along said vertical scan direction being dependent on a thickness of said patient and on a localization of said particular bone at different positions along said vertical scan direction; the lateral image is produced by performing a vertical scan of a standing patient along the vertical scan direction by the lateral radiation source (123) and the lateral radiation detector (124); the modulation of the drive current intensity of at least the side radiation source (123) along the vertical scan direction is dependent on a thickness of the patient and on a localization of the particular bone at different positions along the vertical scan direction; 11. A method according to any one of claims 1 to 10, wherein the frontal and lateral images are produced during the same vertical scan (3).

12. The driving current intensity modulation of the front radiation source (121) and / or the side radiation source (123) is reducing the overall radiation dose received by a patient during said vertical scan; For the frontal image and / or the lateral image, for all or a part of the thickness of the patient along the vertical scanning direction, the local image contrast of the identified bone localization at different imaging positions along the same vertical scanning direction is not reduced below a given contrast threshold.

12. The radiation imaging method according to claim 1, wherein the radiation imaging method is automatically performed without voltage intensity modulation of the front radiation source (121) and / or the lateral radiation source (123) in order to improve the compromise between:

13. The driving current intensity modulation of the front radiation source (121) and / or the side radiation source (123) is reducing the overall radiation dose received by a patient during said vertical scan; Improving the contrast-to-noise ratio, or the ratio between the contrast-to-noise ratio and the square root of the total radiation dose of the identified specific bone localization at different imaging positions along the vertical scan direction, for the frontal image and / or the lateral image, for all or part of the patient thickness along the vertical scan direction, with the same total radiation dose but without drive current intensity modulation, for local image contrast of the identified specific bone localization at different imaging positions along the vertical scan direction; 13. The radiation imaging method according to claim 1, wherein the radiation imaging method is automatically performed without voltage intensity modulation of the front radiation source (121) and / or the lateral radiation source (123) in order to improve the compromise between:

14. The en face multi-energy image acquisition may include acquiring at least two energy bins, or at least three energy bins, or at least six energy bins. and / or at most 20 energy bins, or at most 15 energy bins, or at most 10 energy bins (3) and / or said lateral multi-energy image acquisition includes at least two energy bins, or at least three energy bins, or at least six energy bins. and / or at most 20 energy bins, or at most 15 energy bins, or at most 10 energy bins The method of any one of claims 1 to 13, further comprising the steps of:

15. For each of the radiation detectors (122, 124), the pixel size of the radiation detector is in the range of 50 μm to 250 μm, alternatively in the range of 80 μm to 150 μm, alternatively about 100 μm; and / or the overall height of the radiation detector is in the range of 0.1 cm to 1.2 cm, or in the range of 0.2 cm to 1.0 cm, or in the range of 0.3 cm to 0.7 cm; and / or the overall width of the radiation detector is in the range of 10 cm to 80 cm, or in the range of 20 cm to 70 cm, or in the range of 30 cm to 60 cm; and / or the radiation detector is capable of operating in a time delay and sum mode; 15. A radiation imaging method according to any one of claims 1 to 14.

16. 16. A radiographic imaging method according to any one of claims 1 to 15, wherein the identified specific bone localization comprises, and preferably is, the patient's spine.

17. 17. The radiation imaging method according to any one of claims 1 to 16, wherein the drive current intensity modulation of the front radiation source (121) and / or the side radiation source (123) is also performed to reach a signal-to-noise ratio value for the front image and / or the side image that is constant and common for a majority of the imaging positions along the vertical scan direction, preferably for all the imaging positions along the vertical scan direction, but which can take two different values ​​for the front image and the side image, respectively.

18. 14. The radiological imaging method of claim 13, wherein for each of the frontal and / or lateral images the signal-to-noise ratio value is constant and pre-determined for each different patient organ being imaged.

19. for a frontal image of the patient's spine, a standard signal-to-noise ratio value corresponds to a number of X-ray photons received per detector pixel comprised between 50 and 70, the operator of the radiographic imaging method preferably having the possibility, via a manual command, to deviate from the standard value by at least -25% or +100%, more preferably by at least -50% or +200%, and / or for lateral images of the patient's spine, a standard signal-to-noise ratio value corresponds to a number of X-ray photons received per detector pixel comprised between 20 and 40, the operator of the radiographic imaging method preferably having the possibility, via a manual command, to deviate from the standard value by at least -25% or +100%, more preferably by at least -50% or +200%, 15. A radiation imaging method according to claim 13 or 14.

20. 20. A radiation imaging method according to any one of claims 1 to 19, wherein the front and / or lateral images, after having undergone at least the improvement of the local image contrast, are normalised by homogenisation of the raw radiation in order to remove image artefacts arising from the drive current intensity modulation, preferably the front and / or lateral images, after having been normalised, are subjected to a contrast enhancement step.

21. 21. The radiation imaging method according to claim 1, wherein the localization of the identified specific bones excludes, if any, metallic prostheses of parts of the skeleton of the patient's body or metallic parts, such as, for example, metallic protective gear, which are worn on the patient's body before performing the radiation imaging method.

22. 22. A method according to any preceding claim, wherein the current intensity modulation is maximized such that the vertical scan velocity is also maximized at a constant value.

23. 23. A method according to any one of the preceding claims, wherein the operational mode can be manually turned on or off by an operator of the method.

24. 24. The radiation imaging method according to any one of the preceding claims, wherein the operating mode is dedicated to vertical scanning of large and / or obese patients and / or the operating mode is dedicated to vertical scanning of pediatric patients.

25. 25. The radiation imaging method of claim 1, wherein 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. 26. A radiation imaging method according to any one of the preceding claims, wherein the current intensity modulation is in the range of at least 20mA to 300mA, preferably in the range of 10mA to 400mA.

27. 27. A method according to any preceding claim, wherein the vertical scan speed is in the range of at least 8 cm / sec to 20 cm / sec, preferably in the range of 0.4 cm / sec to 35 cm / sec.

28. 28. The radiation imaging method of claim 1, wherein each of the frontal scout views and / or the lateral scout views is generated by performing a preparatory vertical scan of a standing patient along a vertical scan direction with a reduced overall radiation dose compared to each of the frontal and lateral images before generating each of the frontal and lateral images (1), preferably the reduced overall radiation being less than 10% of the overall radiation dose, more preferably less than 5% of the overall radiation dose.

29. 29. A method of radiological imaging according to any one of claims 1 to 28, wherein pixels in the scout view are collected by zones of NxN pixels, preferably ranging from 2x2 pixels to 10x10 pixels, to create an imaging zone.

30. 30. The method of claim 1, wherein the image or the imaging zone is processed to identify corner points (60), which are then used to calculate (22) the thickness profile and to identify (21) the localization of the particular bone in a standing patient along the vertical scan direction.

31. 31. The method of claim 1, wherein the image or the imaging zone is processed by a neural network to calculate (22) the thickness profile and to identify (21) the localization of the particular bone in a standing patient along the vertical scan direction.

32. 32. The radiation imaging method according to any one of claims 1 to 31, wherein the two radiation sources (121, 123) slide vertically to perform a vertical scan of the pelvis or spine or whole body of a standing patient along a vertical scanning direction.

33. 33. The radiation imaging method according to claim 1, wherein the two radiation detectors (122, 124) are associated with the two radiation sources (121, 123), respectively, the two radiation detectors (122, 124) being two photon counting detectors (PCD), each of which is associated with an automatic image processing function that automatically balances the image density whatever the amount of radiation received at the sensitive surface of the radiation detector in order to homogenize the response of the detector.

34. 34. The radiation imaging method according to claim 1, wherein the two radiation detectors (122, 124) are associated with the two radiation sources (121, 123), respectively, and the two radiation detectors (122, 124) are two multi-energy counting detectors, preferably two energy-resolving photon counting detectors (ERPCD).

35. 35. The method of claim 1, wherein the radiation is X-rays.

36. 36. A method according to any one of the preceding claims, wherein the voltage strength of the frontal radiation source is above 90 kVp, or more preferably above 100 kVp.

37. 37. A radiation imaging method according to any one of claims 1 to 36, wherein the second energy threshold is selected 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 selected between 50 keV and 90 keV, preferably between 60 keV and 80 keV, more preferably the second energy threshold is selected to be 70 keV.

38. 38. A radiation imaging method according to any one of claims 1 to 37, wherein the first energy threshold and / or the second energy threshold are varied and / or associated spectral filtering, preferably k-edge filtering, is used and adjusted depending on the thickness of the patient and / or the localization of specific bones of the patient at different imaging positions along the vertical scan direction.

39. the second frontal image includes information that allows assessing (7) the patient's bone density, and the second lateral image includes information that allows assessing (7) the patient's bone density, and / or the combined frontal image shows a local image contrast of the identified specific bone localization at different imaging positions along the vertical scanning direction sufficient to perform (5) a diagnosis on a patient, and the combined lateral image shows a local image contrast of the identified specific bone localization at different imaging positions along the vertical scanning direction sufficient to perform (5) a diagnosis on a patient.

39. A method of radiographic imaging according to any one of the preceding claims.

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