X-ray mammography apparatus and method using two X-ray sources

Abstract

The invention relates to an X-ray mammography apparatus (100, 200). According to the invention, the apparatus comprises a first source (10a) emitting a first X-ray flux (11a), a second source (10b) emitting a second X-ray flux (11b), an X-ray image detector (30) arranged in a first imaging configuration for capturing the first X-ray flux (11a) transmitted through a portion of the breast and, respectively, in a second imaging configuration for capturing the second transmitted X-ray flux (11b), said apparatus (100, 200) having in the second imaging configuration an optical magnification greater than or equal to 8 and less than 20 and a processing unit (40) configured to determine a mammographic absorption image from the first imaging configuration and to reconstruct, from the second imaging configuration, a phase contrast image. Figure for abstract: Fig. 1

Description

Title of the invention: Apparatus and method for X-ray mammography using two X-ray sources Technical field of the invention

[0001] The present invention relates generally to an apparatus and method for X-ray mammography.

[0002] More specifically, the invention relates to an X-ray mammography apparatus and method for the characterization of breast microcalcifications in vivo. State of the art

[0003] Breast cancer is now the leading cancer incident in women and also the leading cause of cancer death in women (685,000 deaths in 2020 worldwide), ahead of lung and colorectal cancers. It represents one in four cancer incidents in women. In 2020, 2.3 million new cases were reported worldwide.

[0004] Breast microcalcifications are calcium deposits in breast tissue and appear as small, bright spots on conventional mammographic images. Microcalcifications play a crucial role in breast cancer screening, particularly for non-palpable breast cancers, and are present in approximately one-third of all malignant lesions detected during screening mammography. Microcalcifications are more common in ductal carcinoma in situ than in invasive breast cancers.

[0005] Absorption X-ray imaging consists of measuring the differences in opacity of an object to X-rays, induced by its inhomogeneity in terms of materials or density. The absorption X-ray imaging technique is appropriate when the objects studied are made of materials having sufficient absorption differences.

[0006] X-ray mammography devices are known. These devices are functional because they allow mammographic images to be obtained by absorption of patient's breasts. However, in the event of detection of objects, for example microcalcifications, it is necessary to take a sample from the patient's breast, which is invasive and painful, and to analyze this sample on a second X-ray imaging device to observe this detected object more precisely.

[0007] Following the collection of a macrobiopsy, the practitioner can use the second specimen radiography device to radiograph this sample. These second imaging devices are functional because they allow absorption images to be obtained from the sample taken. However, such images have low contrast and poor spatial resolution, thus limiting their use. In addition, the use of such images can lead to errors caused by the low contrast and low resolution of these images. However, to date, commercially available specimen radiography systems are based on the so-called absorption X-ray imaging technique and provide images with low spatial resolution. Therefore, in this case, at least two X-ray imaging devices are required, which leads to problems of cost, space, and analysis and implementation time because the analysis and imaging of the sample is often performed at a different location than the absorption mammographic image.

[0008] Analysis of microcalcifications to distinguish their types is very useful in discerning the characteristics of breast lesions and thus improving the early diagnosis of breast cancer.

[0009] To date, the analysis of microcalcifications is mainly carried out in pathology departments on tissue samples taken during macrobiopsies of the patient's breast. Pathologists thus carry out pathological studies by optical microscopy on samples prepared from macrobiopsies. These analyses by optical microscopy require sample preparation which is time-consuming, expensive and delays obtaining results. In addition, the detection of a suspicious area necessarily involves a macrobiopsy, which is tedious and uncomfortable for the patient.

[0010] It is desirable to provide an apparatus and a method allowing the in vivo detection and analysis of microcalcifications in order to distinguish and classify them into different types, quickly, efficiently and painlessly for the patient. Presentation of the invention

[0011] In order to overcome the aforementioned drawbacks of the state of the art, the present invention proposes an X-ray mammography apparatus using two X-ray sources, said apparatus comprising at least: - a breast platform and a compression pad arranged to position and immobilize a portion of a patient's breast; - a first mobile X-ray source arranged in a first imaging configuration to emit, from an emission spot having a diameter greater than or equal to 50 micrometers (pm), preferably between 50 pm and 2 mm, a first flux of X-rays towards a part of the patient's breast, the part of the breast being immobilized between the platform and the compression tablet, - a second mobile X-ray source arranged in a second imaging configuration to emit, from an emission spot having a diameter of between 1 pm and 20 pm, a second X-ray flux, the second X-ray flux being directed towards a portion of the breast of the immobilized patient, - an X-ray image detector arranged in the first imaging configuration to capture the first X-ray flux transmitted through the portion of the breast and, respectively, in the second imaging configuration to capture the second X-ray flux transmitted through the portion of the breast, - the platform and the compression tablet being located between the X-ray image detector and the first X-ray source in the first imaging configuration or, respectively, between the X-ray image detector and the second X-ray source in the second imaging configuration, - a source support on which the first X-ray source and the second X-ray source are mounted, said source support being arranged to alternately position the first X-ray source in the first imaging configuration and the second X-ray source in the second imaging configuration, - a control unit configured to activate or deactivate at least the first X-ray source in the first imaging configuration or the second X-ray source in the second imaging configuration, said activation of the first X-ray source or the second X-ray source being carried out alternately (or asynchronously), said apparatus having in the second imaging configuration a distance between the second X-ray source and the X-ray image detector of between 80 cm and 1.6 m and an optical magnification greater than or equal to 8 and less than 20 and - a processing unit configured to determine a mammographic absorption image of the portion of the patient's breast from the first X-ray flux captured by the X-ray image detector in the first imaging configuration and to reconstruct, from the second X-ray flux captured by the X-ray image detector in the second imaging configuration, a phase contrast image of the portion of the patient's breast.

[0012] Thanks to the arrangement of the apparatus according to the present disclosure, it is possible to obtain two distinct imaging configurations which make it possible to determine, with the same apparatus and the same X-ray image detector, an absorption mammographic image of a part of the breast and a phase contrast image of a portion of the part of the patient's breast previously imaged, with a higher optical magnification than the absorption mammographic image.

[0013] As a result, with such a device, gains in volume, implementation cost and analysis time are achieved compared to state-of-the-art techniques and devices which require at least two separate imaging devices.

[0014] Furthermore, thanks to such a device, it is no longer necessary to perform a macrobiopsy of the patient's breast for benign cases, which simplifies the acquisition of the phase contrast image and improves its implementation time while improving the patient's comfort.

[0015] Then, the arrangement of the two X-ray sources on the source support, the compression tablet, the breast support and the X-ray image detector makes it possible to obtain in the second imaging configuration, a high optical magnification, which makes it possible to capture a particular phase shift on the imaging detector and to analyze this phase shift in order to be able to use phase contrast imaging.

[0016] The use of phase contrast imaging makes it possible to reconstruct images of the portion of the breast imaged in the second configuration with high contrast and high spatial resolution in 2D.

[0017] Other advantageous and non-limiting characteristics of the apparatus according to the invention, taken individually or in all technically possible combinations, are as follows.

[0018] According to a particular and advantageous aspect, the apparatus has in the first imaging configuration a distance between the first X-ray source and the detector of between 50 cm and 120 cm and an optical magnification greater than or equal to 1 and less than or equal to 2.

[0019] According to another particular and advantageous aspect, in the second imaging configuration, the second X-ray flux transmitted through the compression tablet and the platform propagates in free field towards the X-ray image detector.

[0020] In an exemplary embodiment, the source support comprises a rail and wherein the control unit is configured to move at least the first source and the second source along the rail of the source support so as to position: i) either the first X-ray source in the first imaging configuration, ii) or the second X-ray source in the second imaging configuration.

[0021] Advantageously, in the first imaging configuration, the X-ray image detector is positioned opposite the first X-ray source, and in the second imaging configuration, the X-ray image detector is positioned opposite the second X-ray source.

[0022] Advantageously, in the first imaging configuration, the first X-ray source is arranged to emit the first X-ray flux in an emission cone around a propagation axis oriented vertically and directed towards the ground and, in which, in the second imaging configuration, the second X-ray source X-ray is arranged to emit the second X-ray flux in an emission cone around a propagation axis oriented vertically and directed towards the ground.

[0023] Advantageously, the X-ray image detector comprises a matrix of pixels having a first spatial dimension and a second spatial dimension, the first spatial dimension being greater than or equal to 10 cm and the second spatial dimension being greater than or equal to 10 cm.

[0024] Advantageously, the processing unit is configured to determine, by using a contour detection algorithm on said phase contrast image, the presence of an object in said phase contrast image and a morphology of each detected object.

[0025] In an exemplary embodiment, the apparatus comprises at least one of the following elements: a support on which are mounted at least the source support, the breast platform and the compression tablet, the X-ray image detector, a housing associated with the support, the housing receiving at least the source support, the first X-ray source and the second X-ray source, the breast platform and the compression tablet, the X-ray image detector, a device for holding the support on the ground.

[0026] According to a particular and advantageous aspect, the apparatus comprises a detector adjustment device configured to move the detector in at least one spatial direction so as to adjust the distance between the detector and the first X-ray source in the first imaging configuration or so as to adjust the distance between the detector and the second X-ray source in the second imaging configuration, and / or the adjustment device being adapted to adjust an orientation of the detector in at least one rotation.

[0027] According to a particular and advantageous aspect, the apparatus comprises a position adjustment device for the breast platform and the compression tablet, the position adjustment device being adapted to adjust a position of the breast platform and the compression tablet relative to the first X-ray source in the first imaging configuration or relative to the second X-ray source in the second imaging configuration.

[0028] According to another particular and advantageous aspect, the apparatus comprises another device for adjusting the position and / or orientation of the source support to adjust a position of said source support relative to the X-ray image detector along at least one spatial direction, said at least one spatial direction corresponding to a translation of said source support relative to the X-ray image detector and / or to adjust the orientation of the source support relative to the X-ray image detector according to at least one rotation angle.

[0029] Advantageously, in the first imaging configuration, the control unit is configured to move the first X-ray source to different positions along the source support (62) and, for each position, determine an absorption mammographic image and a phase contrast image.

[0030] In one application, said apparatus is configured to reconstruct: a mammographic absorption image of a portion of the patient's breast by tomosynthesis from at least three absorption images of said portion of the patient's breast, the three absorption images being taken in three distinct orientations and / or a phase contrast image by tomosynthesis of the portion of the patient's breast from at least three phase contrast images of said portion of the patient's breast, the three phase contrast images being taken in three distinct orientations.

[0031] The invention also provides an X-ray mammography method comprising the following steps: - arrangement of an apparatus according to the present disclosure in a first imaging configuration, the first X-ray source, the breast platform, the compression pad, the wedge and the detector being arranged according to the first imaging configuration, a portion of a breast 1 of a patient being immobilized between the platform and the compression pad; - emission of a first flux of X-rays from the emission spot of the first X-ray source in free field and in the direction of the part of the patient's breast immobilized between the platform and the compression tablet, the emission spot of the first X-ray source having a diameter greater than or equal to 50 pm; - detection of a first intensity X-ray image via the detector to obtain a first absorption image of a part of the patient's breast 1; - arrangement of the same apparatus in a second imaging configuration, the second X-ray source, the breast platform, the compression pad, the wedge and the detector being arranged according to the first imaging configuration, the part of a breast of a patient being immobilized between the platform and the compression pad, said apparatus having in the second imaging configuration a distance between the second X-ray source and the X-ray image detector of between 80 cm and 1.6 m and an optical magnification greater than or equal to 8 and less than 20; - emission of a second flux of X-rays from the emission spot of the second X-ray source in free field and in the direction of a portion of the part of the patient's breast immobilized between the platform and the compression tablet, the emission spot of the second X-ray source having a diameter of between 1 pm and 20 pm; - detection of a second X-ray image in intensity via the detector; - processing of the second image to determine a phase shift image and reconstruct, from this phase shift image, a phase contrast image of the portion of the patient's breast.

[0032] Of course, the various features, variants and embodiments of the invention may be combined with each other in various combinations to the extent that they are not incompatible or mutually exclusive. Detailed description of the invention

[0033] The description which follows with reference to the appended drawings, given as non-limiting examples, will make it clear what the invention consists of and how it can be implemented.

[0034] In the attached drawings:

[0035] [Fig-1] is a schematic representation in profile view of a device according to a first embodiment used in a first imaging configuration;

[0036] [Fig.2] is a schematic representation in front view of the apparatus of the first embodiment used in the first imaging configuration;

[0037] [Fig.3] is a zoomed schematic representation in front view of a source support used in the apparatus according to the first embodiment used in the first imaging configuration;

[0038] [Fig.4] is a schematic representation in sectional view of a first X-ray intensity image obtained by a processing unit of the apparatus according to the first embodiment used in the first imaging configuration;

[0039] [Fig.5] illustrates an X-ray absorption mammographic image obtained with the apparatus according to the first embodiment used in the first imaging configuration;

[0040] [Fig.6] is a schematic representation in profile view of the apparatus according to the first embodiment used in a second imaging configuration;

[0041] [Fig.7] is a schematic representation in front view of the apparatus according to the first embodiment used in the second imaging configuration;

[0042] [Fig.8] is a zoomed schematic representation in front view of the source support of the apparatus according to the first embodiment in the second imaging configuration

[0043] [Fig.9] is a schematic representation of a second image of a phase shift determined by a processing unit of the apparatus according to the first embodiment used in the second imaging configuration;

[0044] [Fig. 10] illustrates a series of images (10A, 10B, 10C) of absorption of different spots visible on the absorption images obtained with the apparatus according to the first embodiment in the first imaging configuration and a series of phase contrast images (10D, 10E, 10F) of the same spots reconstructed from the second imaging configuration;

[0045] [Fig. 11] is a schematic representation in profile view of an apparatus according to a second embodiment used in the first imaging configuration;

[0046] [Fig. 12] is a schematic representation in front view of the apparatus according to the second embodiment used in the first imaging configuration;

[0047] [Fig. 13] is a schematic representation in profile view of an apparatus according to a second embodiment used in the second imaging configuration;

[0048] [Fig. 14] is a schematic representation in front view of the apparatus according to the second embodiment used in the second imaging configuration;

[0049] [Fig. 15] is a schematic representation of a method according to the present invention.

[0050] Device

[0051] A first embodiment of an X-ray mammography apparatus 100 using two X-ray sources will now be described with the aid of FIGS. 1 to 10.

[0052] As described in the present disclosure, the apparatus 100 has two imaging configurations, a first imaging configuration using a first X-ray source 10a to determine a mammographic absorption image of a portion of a breast 1 of a patient, hereinafter the patient, and a second imaging configuration using a second X-ray source 10b to reconstruct a phase contrast image of a portion of the portion of the breast 1 of the patient.

[0053] For this purpose, the apparatus 100 comprises the first X-ray source 10a, the second X-ray source 10b, a platform 20 for supporting the breast under examination as well as a compression tablet 22, an X-ray image detector 30, a processing unit 40, a control unit 51 and a source support 62.

[0054] As explained in detail below, the first X-ray source 10a and the second X-ray source 10b are used alternately, in particular here the first source is used in the first imaging configuration and the second source is used in the second imaging configuration.

[0055] The first imaging configuration of the device 100 and an example of a mammography image obtained in this first imaging configuration will now be described using FIGS. 1 to 5.

[0056] As illustrated in Figures 1 to 3, in the first imaging configuration, the first X-ray source 10a is arranged to emit from an emission spot a first flux 11a of X-rays towards the breast 1 of the patient.

[0057] Typically, the emission spot of the first X-ray source 10a has a diameter Da greater than or equal to 50 pm, preferably between 50 pm and 2 mm. The diameter Da of the emission spot is the minimum diameter of the first X-ray flux 11a, also called the focusing diameter of the first X-ray source 10a.

[0058] In the first imaging configuration, the compression tablet 22 is spaced from the first X-ray source 10a by a distance dla of between 20 cm and 1 m, preferably between 50 cm and 1 m, in order to adjust a magnification value of the apparatus 100 in the first imaging configuration which will be explained below. This distance dla is determined between a plane Pla of the emission spot of the first X-ray source 10a, here oriented perpendicular to the propagation axis Aa of the first X-ray source 10a (or perpendicular to the z axis) and a plane P2a of the compression tablet 22 oriented parallel to the emission plane Pla of the first X-ray source 10a and perpendicular to the propagation axis Aa of the first X-ray source 10a.Here, the plane of the second main surface 25 of the compression tablet 22 is merged with this plane P2a.

[0059] In the first imaging configuration, the X-ray image detector 30 is positioned at a distance d2a from the first X-ray source 10a of between 50 cm and 120 cm, preferably between 60 cm and 80 cm from the first X-ray source 10a. This distance d2a is determined between the emission plane Pla of the first X-ray source 10a and a plane P3 of the X-ray image detector 30 oriented parallel to the plane Pla of the emission spot of the first X-ray source 10a and perpendicular to the propagation axis Aa of the first X-ray flux 11a. Here, the plane P3 is included in an active surface 31 of the X-ray image detector 30 which is described below.

[0060] The distance dla first source 10a - compression tablet 22 and the distance d2a first source 10a - X-ray image detector 30 make it possible to define a first optical magnification of the apparatus 100 as being the ratio between the distance dla (distance separating the first X-ray source 10a from the compression tablet 22) and the distance d2a (distance separating the first X-ray source 10a from the X-ray image detector 30).

[0061] Here in particular, in this configuration, the first optical magnification of the device 100 is greater than or equal to 1 and less than or equal to 2. Preferably, the first optical magnification of the device 100 is between 1 and 2 in order to obtain better resolution on the mammographic image by absorption of the breast 1 of the patient with the device 100 in the first configuration.

[0062] As illustrated in [Fig. 1], the first flux 11a of X-rays emitted by the first source 10a of X-rays has a propagation axis Aa oriented vertically and directed towards the ground. In other words, the propagation axis Aa is parallel to the z axis of the orthonormal reference frame shown in [Fig.l] and defined by the x, y, and z axes. Such a configuration makes it possible to minimize reflections of X-rays on other elements external to the device 100.

[0063] The first X-ray source 10a is a conventional X-ray mammography source, for example a source based on a rotating anode mammography tube. It has a spot diameter Da (at the output of the first source 10a) greater than or equal to 50 pm. The first X-ray source 10a generates, for example, an X-ray emission spectrum of between 20 keV and 70 keV, by applying a high voltage of between 20 kV and 70 kV, with a current intensity greater than 30 mA and a power greater than 1 kW.

[0064] In the first imaging configuration, the first X-ray flux 11a, at the output of the first X-ray source 10a, has a power greater than or equal to 1 kW. Generally, the first X-ray source 10a emits the first X-ray flux 11a in an emission cone, specific to this source 11a. Here, by emission cone, is meant a cone of revolution around a propagation axis Aa, having as generator the diameter Da of the emission spot and having an apex angle or opening angle at the output of the first X-ray source 10a. The emission cone represents the volume in which the first X-ray flux 11a propagates from the emission spot of the first X-ray source 10a towards the part of the patient's breast which is immobilized between the platform 20 and the compression tablet 22.In other words, the first flux 11a of X-rays at the output of the first source 10a of X-rays is divergent, and propagates along the emission cone of the first source 10a of X-rays to the compression tablet 22.

[0065] In a known manner, the platform 20 and the compression tablet 22 are each mounted to move in translation along the z axis, in order to adjust the position of the platform 20 to the size of the patient and to adjust the position of the compression tablet 22 to the size of the breast 1 examined.

[0066] Preferably, the opening angle of the emission cone of the first X-ray source 10a, which is the total angle, is between 10 degrees and 45 degrees.

[0067] The first flux 11a of emitted X-rays has a wavelength between 0.018 nm and 0.062 nm. It propagates in a free field at the output of the first X-ray source 10a towards the compression tablet 22 of the apparatus 100. Here, by free field, we mean propagation in free space. In other words, the first flux 11a of X-rays does not encounter any other element of the apparatus 100 before reaching the compression tablet 22.

[0068] It is noted that the first flux 11a of X-rays has a first initial wavefront representing its propagation at the output of the first source 10a of X-rays.

[0069] This first flow 1 of X-rays propagates towards the patient's breast 1.

[0070] As schematically illustrated in Figures 1 and 2, the patient's breast 1 is held by the breast platform 20 which supports the patient's breast 1. This breast platform 20 is in this example in the form of a flat plate with a main face 21 oriented parallel to the xy plane, that is to say horizontally.

[0071] As schematically illustrated in [Fig.l], the breast support 20 is associated with the compression tablet 22 arranged to compress the patient's breast 1 onto the breast platform 20, here in particular to compress the patient's breast 1 against the first main face 21 of the breast platform 20. Similarly, the compression tablet 22 is here in the form of a flat plate facing the main face 21 of the breast platform 20 and being oriented parallel to this main face 21 of the breast platform 20. The compression tablet 22 comprises a first main face 23 oriented opposite the first main face 21 of the breast platform 20 and a second main face 25 oriented opposite the outlet of the first X-ray source 10a.It is understood that this compression tablet 22 is movable in at least one spatial direction, corresponding here to a translation of the compression tablet 22 along the z axis away from or towards the breast platform 20 to compress the patient's breast 1 so as to reduce the thickness of the breast 1 as much as possible in order to improve the resolution of the mammographic image by absorption. Of course, it is also possible for the compression tablet 22 as well as the breast support 20 to both be movable, in particular along the z axis, to compress the patient's breast 1 during the radiological examination and then release it at the end of the examination.

[0072] As schematically illustrated in [Fig.l] and [Fig.2], a portion of the breast 1 tablet of the patient is entirely positioned in the emission cone of the first source 10a of X-rays. In other words, this part of the breast 1 tablet is entirely irradiated by the first flow 1 la of X-rays. Thus in this configuration, the entire part of the breast of the compressed patient is irradiated by the first flow 1 la of X-rays, this part is also called part of the breast irradiated by the first flow 1 la of X-rays.

[0073] Here, in this example, the first X-ray source 10a is configured to irradiate the breast 1 for a time period of between 10 milliseconds and 35 seconds in order to have enough signal to determine the absorption mammographic image which will be described below.

[0074] For example, part of breast 1 is irradiated for 10 seconds in order to have a good compromise between the dose of X-rays received by the patient and the quantity of signal acquired to obtain the mammographic absorption image of the patient's breast.

[0075] The first X-ray source 10a is configured to continuously irradiate the compressed breast 1 at a dose between 0.5 mSV and 2.5 mSV. Such a range makes it possible to limit the X-ray dose received by the patient in accordance with health and safety standards while providing enough signal to allow rapid acquisition of the mammographic image by absorption of the portion of the patient's breast 1. For example, the X-ray dose received by exposure to the first X-ray flux 11a is 1 mSv.

[0076] Thus, the first flux 11a of X-rays propagates in a free field from the first source 10a of X-rays to the compression tablet and passes through the compression tablet 22, a portion of the breast 1 as well as the breast platform 20. For this purpose, it is understood that the compression tablet 22 as well as the breast platform 20 are not very absorbent in the wavelength range emitted by the first source 10a of X-rays. Here, by not very absorbent, it is meant that the compression tablet 22 and the breast platform 20 are arranged and / or configured to transmit between 50% and 95% of the first flux 11a of X-rays.

[0077] After passing through the compression tablet 22, the immobilized part of the breast 1 and the breast platform 20, the first X-ray flux 11a reaches the X-ray image detector 30, which is, in the first imaging configuration, positioned facing the first X-ray source 10a. It is thus understood that, in the first imaging configuration, the compression tablet 22 and the breast platform 20 are positioned between the first X-ray source 10a and the X-ray image detector 30.

[0078] In this first embodiment, no optical element (other than the compression tablet 22 and the breast platform 20) is positioned on the optical path of the first flux 11a passing through the breast.

[0079] In this first imaging configuration, the X-ray image detector 30 is arranged to capture the first flux 11a of X-rays passing through the breast 1. It is understood that the first flux 11a of X-rays captured by the X-ray image detector 30 has a wavefront, hereinafter referred to as the first transmitted wavefront, which represents a spatial distribution of the first flux 11a of X-rays passing through the breast 1, the compression tablet 22 and the breast platform 20. The X-ray image detector 30 operates by direct or indirect detection.

[0080] For example, the X-ray image detector 30 operates by indirect detection, using a flat screen comprising a matrix of cesium iodide (Csl) crystals combined with a matrix of CMOS (complementary metal oxide semiconductor) detectors. The X-ray image detector 30 thus comprises a matrix of pixels, each pixel having a side length less than or equal to 100 pm.

[0081] Typically, in the apparatus 100, the X-ray image detector 30 has a size adapted to the first X-ray source 10a and to the second X-ray source 10b used, here in particular to the emission cone of the X-ray source used. In other words, the X-ray image detector 30 is arranged to capture the first total X-ray flux 11a (in the first imaging configuration) and the second total X-ray flux 11b (in the second imaging configuration).

[0082] The X-ray image detector 30 has an active face 31, oriented opposite the X-ray source used (the first X-ray source 10a in the first imaging configuration and, respectively, the second X-ray source 10b in the second imaging configuration) and comprising a pixel matrix 32 in which each pixel is configured to capture a portion of the X-ray flux emitted in the imaging configuration used. The X-ray image detector 30 thus records an intensity image of the X-ray flux having passed through the patient's breast, the compression tablet 22 and the breast platform 20.

[0083] This pixel matrix 32 has a first spatial dimension oriented parallel to a spatial axis (x axis), and a second spatial dimension perpendicular to the first spatial dimension and oriented parallel to the spatial axis y. Advantageously, the pixels of the pixel matrix 32 are arranged in rows and columns.

[0084] Advantageously, the X-ray image detector 30 is a flat screen detector (fiat panel, in English) with a detection surface of at least 10cm x 10cm. The X-ray image detector 30 has an active face 31, oriented opposite the X-ray source 10 and comprising a pixel matrix 32 in which each pixel is configured to capture a portion of the flux 11 of X-rays passing through the sample 1. The image detector 30 thus records an intensity image of the flux of X-rays having passed through the sample 1.

[0085] This pixel matrix 32 has a first spatial dimension oriented parallel to a spatial axis, for example the x axis, and a second spatial dimension perpendicular to the first spatial dimension and oriented parallel to the y spatial axis. Advantageously, the pixels of the pixel matrix 32 are arranged in rows and columns.

[0086] In a non-limiting manner, the first spatial dimension and the second spatial dimension are each greater than 10 cm, here in particular the first spatial dimension is 22.8 cm and the second spatial dimension is 29.2 cm. Advantageously, the first spatial dimension and the second spatial dimension are each less than 40 cm, in order to limit the size of the device 100.

[0087] Thus, in this example, the pixel matrix 32 of the X-ray image detector 30 is rectangular in shape. Of course, the image detector 30 can, in a alternatively, present other shapes, for example a square shape when the first spatial dimension and the second spatial dimension are the same size.

[0088] The pixels of the pixel matrix 32 are all identical and each have a first dimension, oriented parallel to the first spatial dimension of the pixel matrix 32 and a second dimension, perpendicular to the first dimension and oriented parallel to the second spatial dimension of the pixel matrix. The first dimension and second dimension are each less than or equal to 100 pm and preferably between 40 pm and 60 pm. Here, typically, the pixel matrix 32 is made of square-shaped pixels with a side length of 49.5 pm. The pixel matrix 32 of the X-ray image detector 30 comprises a number of pixels ranging from 4000 to 6000 pixels in each direction, for example 4600 pixels in one direction and 5800 pixels in the other direction.

[0089] Thus, in this example, the pixel matrix 32 of the X-ray image detector 30 is rectangular in shape. Of course, the latter may, in a variant, have other shapes, for example a square shape when the first spatial dimension and the second spatial dimension are of the same size.

[0090] The present dimensions of the image detector 30 (size range and pixel size range) and the high number of pixels make it possible to obtain a high spatial resolution absorption mammographic image in the first imaging configuration and a high spatial resolution phase contrast image in the second imaging configuration.

[0091] The first flow 11a of X-rays having been captured by the X-ray image detector 30 is then analyzed by the processing unit 40 of the apparatus 100.

[0092] By processing unit is meant any calculation unit or processor or computer or any other electronic element making it possible to implement a succession of commands and / or calculations. This processing unit 40 typically comprises a processor, a memory and different input and output interfaces.

[0093] By means of its input and output interfaces, the processing unit 40 is programmed to receive any data measured by the X-ray image detector 30.

[0094] Thanks to its memory, the processing unit 40 stores a computer application, consisting of computer programs comprising instructions whose execution by the processor makes it possible to reconstruct the mammographic image by absorption in the first imaging configuration and the phase contrast image of the part of the patient's breast 1 in the second imaging configuration.

[0095] The processing unit 40 of the apparatus 100 is at least connected to the X-ray image detector 30 described above. By connected, it is meant that the processing unit 40 is arranged to communicate with another element, for example, by being configured to transmit and / or receive data from this element (here for example by wire).

[0096] Here, in this case, in the first imaging configuration, the processing unit 40 is configured to determine a mammographic image by absorption from the first flow 11a of X-rays captured by the X-ray image detector 30.

[0097] In practice, the first X-ray flow 11a corresponds to an intensity signal which is analyzed by the processing unit 51 to determine a first intensity image of the first X-ray flow 11a transmitted through the immobilized part of the patient's breast.

[0098] Indeed, the spatial distribution of the transmitted intensity of the first X-ray flux 11a and captured by the X-ray image detector 30 corresponds to an absorption signal of the first X-ray flux 11a which has been modified during its passage through the patient's breast 1.

[0099] For this purpose, [Fig. 4] schematically illustrates an example in cross-sectional view of the breast 1 determined by the processing unit 40 from the first flow 11a of X-rays captured by the X-ray image detector 30 in the first imaging configuration. More precisely, [Fig. 4] represents an intensity profile of the X-rays captured on the image detector 30 in the first imaging configuration by a plurality of lines of pixels extending for example along the x axis.

[0100] This first intensity image has a curved shape. In other words, the intensity signal has a main part PSa in which the intensity signal follows a bell curve variation and two secondary parts PSb, framing the main part, in which the intensity signal is (substantially) constant.

[0101] In the first imaging configuration, the X-ray image detector 30 is configured to detect the transmitted intensity and directly obtain an inverted image of the absorption by the part of the breast which is irradiated by the X-ray flux 11a in a manner known to those skilled in the art. The publication Dance, DR, Lemoigne, Y., Caner, A., & Rahal, G. (2007). Physical principles of mammography. Physics for Medical Imaging Applications, 240, 355 describes for example the X-ray absorption mammography imaging technique. Indeed, the high intensity signal in a pixel zone corresponds to a low absorption in the region of the breast opposite this pixel zone. On the contrary, a low intensity signal in another pixel zone corresponds to a high absorption in another region of the breast opposite this other pixel zone.

[0102] The detected intensity thus directly provides a mammographic image by absorption of the breast.

[0103] [Fig.5] illustrates an absorption mammographic image of a portion of the breast determined by the apparatus 100 in the first imaging configuration. As As can be seen, the image obtained by the first imaging configuration has high contrast and good resolution. The dark background corresponds to regions of low absorption at the flux 11a of X-rays. The light filaments and points correspond to regions of higher absorption at the flux 11a of X-rays.

[0104] The processing unit 40 may also be configured to analyze the absorption mammographic image of the breast and detect objects in this image. The objects thus detected are for example characterized by at least one of the following elements: position, size, shape, intensity of the object, etc. Here, in [Fig. 5], an object Oba is detected and sorted according to the intensity and shape of this object Oba. In particular, the bright spots may indicate the presence of microcalcifications. For this purpose, the processing unit 40 may be used to detect microcalcifications present in the absorption mammographic image of the breast determined by the apparatus 100 in the first imaging configuration.

[0105] To switch from the first imaging configuration to the second imaging configuration, the apparatus 100 uses the control unit 51. The latter is arranged to control the different elements of the apparatus 100, here at least the first X-ray source 10a, the second X-ray source 10b. It is also configured to control the other elements of the apparatus 100, such as at least the X-ray image detector 30 and the processing unit 40.

[0106] As described above, in the first imaging configuration, only the first X-ray source 10a emits a flux of X-rays, corresponding here to the first X-ray flux 11a.

[0107] For this, the apparatus 100 uses the control unit 51 which is configured to activate and deactivate at least the first X-ray source and the second X-ray source, this activation of the first X-ray source and the second X-ray source being carried out asynchronously and sequentially.

[0108] By asynchronous and sequential, it is meant that the activation is carried out in an alternating manner. In other words, in the first imaging configuration, the control unit 51 is configured to activate the first X-ray source 10a and turn off or keep the second X-ray source 10b on standby, whereas in the second imaging configuration, the control unit 51 is configured to activate the second X-ray source 10b and turn off or keep the first X-ray source 10a on standby.

[0109] It is therefore understood that in the first imaging configuration, the second X-ray source does not emit any X-ray flux.

[0110] By control unit 51 is meant any calculation unit or processor or computer or any other electronic element making it possible to implement a succession of commands and / or calculations. This control unit 51 typically comprises a processor, memory and various input and output interfaces. Typically, the control unit 51 may comprise a microcontroller.

[0111] Thanks to its input and output interfaces, the control unit 51 is programmed to receive any data measured by the detector of the device 100 and / or any data analyzed by the processing unit 40. In a non-limiting manner, the device 100 comprises a screen 53 connected to the control unit 51. The control unit 51 is also programmed to control the screen 53 and more generally any Human-Machine interface making it possible to communicate information to a user of the device 100. This screen 53 may or may not be touch-sensitive.

[0112] In practice, the processing unit 40 and the control unit 51 may be two separate calculation modules or a single calculation module, or be the same element performing the functions of the processing unit 40 and the control unit 51.

[0113] In the apparatus 100, the control unit 51 is also configured to move at least the first source 10a and the second source 10b along the source support 62 so as to position alternately: i) the first X-ray source 10a in the first imaging configuration, and ii) the second X-ray source 10b in the second imaging configuration.

[0114] As explained above, in the first imaging configuration, the first X-ray source 10a, the compression tablet 22, the breast platform 20 and the image detector 30 are aligned along the emission axis Aa of the first X-ray source 10a.

[0115] To switch between the two imaging configurations, the first X-ray source 10a and the second X-ray source 10b are mounted on the source support 62. Here, for example, as illustrated in FIGS. 2 and 3, the source support 62 is in the form of an arcuate rail on which the first X-ray source 10a and the second X-ray source 10b are mounted.

[0116] This source support 62 here has a curved shape, in particular in the form of an arc of a circle, and arranged to extend in a plane parallel to the xz plane with a portion of the arc of a circle transverse to the translation axis (z axis) along which the propagation axis Aa of the first X-ray source 10a is aligned. Advantageously, a first motorized actuator makes it possible to move the first X-ray source 10a along the arc of a circle of the source support 62. Similarly, a second motorized actuator makes it possible to move the second X-ray source 10b along the arc of a circle of the source support 62.

[0117] Such a shape thus makes it possible to simply and inexpensively move the first X-ray source 10a and the second X-ray source 10b so as to move from the first imaging configuration to the second imaging configuration. and vice versa from the second imaging configuration to the first imaging configuration.

[0118] Alternatively, the shape support comprises other types of actuators, for example in translation along the x axis and / or the y axis. The rail of the source support 62 can also be linear.

[0119] Thus, it is understood that in the first imaging configuration, the first X-ray source 10a is oriented in the direction of the X-ray image detector 30. As a result, in this configuration, the emission cone of the X-ray flux 11a emitted by the first X-ray source 10a is included in the optical field (or capture zone) of the X-ray image detector 30 whereas conversely, in this first imaging configuration, the second X-ray source 10b is positioned outside the optical field of the X-ray image detector 30. Furthermore, in the first imaging configuration, the second X-ray source 10b is inactive when the first X-ray source 10a is activated.

[0120] Similarly, it is understood that in the second imaging configuration, described below, the emission cone of the flux 11b of X-rays emitted by the second source 10b of X-rays is included in the optical field (or capture zone) of the X-ray image detector 30 whereas conversely, in this second imaging configuration, the first source 10b of X-rays is positioned outside the optical field of the X-ray image detector 30. Furthermore, in the second imaging configuration, the first source 10a is inactive when the second source 10b of X-rays is activated.

[0121] Thus, to switch from the first imaging configuration to the second imaging configuration, the control unit 51 is configured to deactivate (i.e., turn off or put on standby) the first X-ray source 10a and the second X-ray source 10b and move the first X-ray source 10a and the second X-ray source 10b so that the second X-ray source 10b is positioned opposite the X-ray image detector 30.

[0122] The second imaging configuration of the device 100 will now be described with the aid of FIGS. 6 to 8.

[0123] After positioning the second X-ray source 10b, the control unit is configured to activate the second X-ray source 10b and maintain the deactivated state of the first X-ray source 10a.

[0124] Similarly, the second X-ray source 10b is arranged to emit from an emission spot (or light spot) a second flux 11b of X-rays towards the patient's breast 1.

[0125] The emission spot of the second X-ray source 10b has a diameter Db of between 1 pm and 20 pm. The diameter Db of the emission spot is the diameter minimum of the second X-ray flux 11b also called the focusing diameter of the second X-ray source 10b. The focal spot diameter Db is the minimum diameter of the second X-ray flux 11b. In other words, the second source 10b is a microfocus source. In particular, the use of the second X-ray flux having such a diameter D at the output of the second source 10b makes it possible to obtain a second spatially and temporally coherent X-ray flux 11b, which makes it possible, as will be described below, to determine the image by phase contrast.

[0126] On the other hand, in the second imaging configuration, the compression tablet 22 is spaced from the second X-ray source 10b by a distance dlb comprised between 0 cm and 20 cm, preferably between 10 cm and 20 cm in order to adjust a magnification value of the apparatus 100 in the second imaging configuration which will be explained below. This distance dlb is determined between an emission plane Pib of the second X-ray source 10b. Preferably, the emission plane Pib of the second X-ray source 10b is oriented perpendicular to the propagation axis Ab of the second X-ray source 10b (or perpendicular to the z axis) and a plane P2b of the compression tablet 22 oriented parallel to the emission plane Pib of the second X-ray source 10b and preferably perpendicular to the propagation axis Ab of the second X-ray source 10b.Here, this plane P2b is merged with the plane of the second main surface 25 of the compression tablet 22. Alternatively, the propagation axis Ab is slightly inclined by an angle of inclination included in a range, for example from -15 degrees to + 15 degrees, relative to the vertical axis z. For example, in a tomosynthesis application, the source is inclined while keeping the detector horizontal in certain configurations. In other configurations, the source and the detector are inclined. In yet another configuration, the axis of the source remains vertical and only the detector is inclined.

[0127] Finally, in this second imaging configuration, the X-ray image detector 30 is positioned at a distance d2b from the second X-ray source 10b of between 80 cm and 1.70 m, preferably between 80 cm and 1.50 m from the second X-ray source 10b. This distance d2b is determined between the emission plane Pib of the second X-ray source 10b and the plane P3 of the X-ray image detector 30, preferably oriented parallel to the emission plane Pib of the second X-ray source 10b and preferably perpendicular to the propagation axis Ab of the second X-ray source 10b. For example, this plane P2b coincides with the plane of the second main surface 25 of the compression tablet 22. The active surface 31 of the X-ray image detector 30 is included in the plane P3 described above. Alternatively, the propagation axis Ab is slightly inclined by an angle of inclination within a range, for example, from -15 degrees to +15 degrees, relative to the vertical axis z and the normal to the active surface 31 of the X-ray image detector 30 is inclined by the same angle of inclination.

[0128] The distance dlb second source 10b - compression tablet 22 and the distance second source 10b - X-ray image detector 30 make it possible to define a second optical magnification of the apparatus 100 as being the ratio between the distance d2b (distance separating the second X-ray source 10b from the X-ray image detector 30) and the distance dlb (distance separating the second X-ray source 10b from the compression tablet 22).

[0129] Here in particular, in this configuration, the second optical magnification of the apparatus 100 is greater than or equal to 8 and less than or equal to 30. Preferably, the second optical magnification of the apparatus 100 is between 8 and 20, and even better between 8 and 15, in order to obtain better resolution on the phase contrast image reconstructed by the apparatus 100.

[0130] It is thus understood that the second optical magnification is greater than the first optical magnification.

[0131] To obtain such a variation in magnification, firstly, the detector 30 is mounted to move in translation along the z axis.

[0132] In an exemplary embodiment, the compression tablet 22 and the breast platform 20 remain at a fixed z-position for a given patient between the first imaging configuration and the second imaging configuration. In this case, the source support 62 is mounted to be movable in translation along the z-axis.

[0133] In another exemplary embodiment, the source support 62 remains in a fixed position in z between the first imaging configuration and the second imaging configuration. In this case, the compression tablet 22 and the breast platform 20 are mounted to move in translation along the z axis. However, for this movement to be possible, it is understood that the distance of the patient from the ground must be modified. For this purpose, the apparatus 100 comprises at least one other platform or wedge 110 arranged to support the patient upright and to modify the distance between the patient and the ground. This wedge 110 can support the patient at the level of her feet.For this purpose, this wedge may be in the form of a tray on which the patient stands and may be controlled in position along the z axis by the control unit 51 in order to synchronize the movement of the compression tablet 22 and the breast support 20 with the distance of the patient from the ground. Of course, in a variant, it is possible to use a plurality of interlocking or individual wedges and to select the one making it possible to adapt the position of the patient relative to the ground with the movement of the breast support 20 and the compression tablet 22.

[0134] Advantageously, the apparatus 100 also comprises a device 63 for adjusting the position of the wedge 110 configured to move the wedge 110 in at least one spatial direction, corresponding here to a translation of the wedge 110 along the z axis between the first and second imaging configuration.

[0135] In yet another embodiment, the source support 62, the compression tablet 22 and the breast platform 20 are each mounted to be movable in translation along the z axis, as well as possibly the wedge 110.

[0136] For example, in the first imaging configuration, it is sufficient to adjust, manually or automatically, at least one of the distances dla, d2a and in the second imaging configuration, at least one of the distances dlb, d2b. Preferably, the distances dla, d2a, dlb, d2b are adjusted using the human-machine interface. In this case, the user enters, for example, the distance dlb (corresponding here to an input data) into the human-machine interface and the control unit automatically moves the compression tablet 22 and the breast support 20.

[0137] For this purpose, the apparatus 100 comprises, for example, a device 60 for adjusting the position of the breast platform 20 and the compression tablet 22 to adjust a position of the breast platform 20 and the compression tablet 22 along at least one spatial direction. Here, the at least one spatial direction corresponds to a translation of the breast platform 20 and the compression tablet 22, i.e. a translation along the z axis (parallel to the propagation axis of the X-ray source used), relative to: - to the first X-ray source 10a, so as to obtain the first optical magnification, or - to the second X-ray source 10b, so as to obtain the second optical magnification.

[0138] Such a configuration thus makes it possible to move the breast platform 20 as well as the compression tablet 22 between the first imaging configuration and the second imaging configuration or vice versa.

[0139] Typically, this position adjustment device 60 may comprise a movable support 60a on which the breast platform 20 is mounted and another movable support 60b on which the compression tablet 22 is mounted. The movable support 60a is arranged to move the breast platform 20, and respectively the movable support 60b is arranged to move the compression tablet 22, along the translation axis (z axis) and modify its position by translation along the axes transverse to the z axes, here the x, y axes. Of course, in a variant, the breast support 20 and the compression tablet 22 may be mounted on a single movable support 60 to simultaneously move the compression platform 22 and the breast platform 20.

[0140] Of course, this position adjustment device 60 can be moved manually or automatically by using at least one motor configured to move the at least one mobile support. Typically, this position adjustment device 60 is controlled by the control unit 50 in order to obtain the desired position and orientation.

[0141] The apparatus 100 also comprises a position adjustment device 61a of the X-ray image detector configured to move the X-ray image detector 30 in at least one spatial direction, corresponding here to a translation of the X-ray image detector 30 relative to: - the first X-ray source 10a, so as to obtain the first optical magnification, or - the second X-ray source 10b, so as to obtain the second optical magnification.

[0142] Such a configuration thus makes it possible to move the X-ray image detector 30 between the first imaging configuration and the second imaging configuration or vice versa. This position adjustment device 61 can operate in a similar manner to the position adjustment device 60 described above. Namely, it can comprise a movable support 61a for modifying the position of the X-ray image detector 30 along the z axis and optionally along the x, y axes, manually or automatically by being motorized.

[0143] In combination or alternatively, the apparatus 100 may comprise an orientation adjustment device 61b of the X-ray image detector 30 for adjusting at least one orientation of the X-ray image detector 30 according to at least one rotation angle.

[0144] Typically, the position and / or orientation adjustment device 61 is part of the same device and may comprise a mobile support 61 arranged to move the X-ray image detector 30 along the translation axis (z axis) and modify its position by translation along the axes transverse to the z axes, here the x, y axes and / or its orientation by rotation around the x, y and / or z axes, by means of rotation elements fixed to the mobile support 61.

[0145] The joint adjustment in orientation of the X-ray source and the detector makes it possible to take images of the breast in a vertical, oblique or even horizontal position.

[0146] It is thus understood that, in the first or second given imaging configuration (for example here the second imaging configuration), it is possible to change both the position of the given X-ray source (here for example the second X-ray source) by moving the X-ray source considered to different points (or positions) Tl-Tn on the source support 62 and to similarly modify the orientation, and optionally the position, of the image detector 30 of X-rays (here by at least one rotation along the x or y axis and optionally a translation along the x axis) via the position and orientation adjustment device 61 of the X-ray image detector so as to produce several absorption images in the first configuration or phase contrast images in the second configuration depending on or independently of the movements of the source. For this purpose, the position of each of the two sources in the xz plane is modified. In particular, in the first configuration, the position of the source 10a is modified according to the different positions Tn to perform tomosynthesis. In the second configuration, the position of the source 10b is also modified according to the different positions Tn. Typically, at each given point Tn, an image of the phase shift is determined by the processing unit 40. Although only four positions Tn are illustrated in [Fig.3], a larger number of points Tn is generally used depending on the trajectory defined by the source support 62. Typically, the source support is arranged so that all the points Tn defined by the shape or trajectory of the source support 62 form a total arc of between 10 degrees and 50 degrees (preferably between 20 degrees and 40 degrees), here ± 20 degrees (°) relative to a reference point Tref on the source support. This reference point can be positioned at the maximum amplitude of the shape of the source support 62 in the case where the support 62 is arc-shaped or at the intersection between the normal axis at the center of the detector and the support 62 in the case where the support 62 is linear. Here, for example, a phase image is determined at each of the Tl-Tn imaging positions, generally at the same dose at each position and for the same exposure time.Preferably, between each position, the control unit 51 is arranged to deactivate the X-ray source used for safety reasons and to limit the radiation dose delivered to the patient.

[0147] For example, in the first imaging configuration, the processing unit can determine, from each absorption image in the first configuration recorded at a given position Tn, for a series of different positions Tn, a pseudo 3D radiographic image of the patient's breast here based on a pseudo 3D absorption mammographic image using a tomosynthesis algorithm. Similarly, in the second imaging configuration, the processing unit can determine, from each phase contrast image determined at a given position Tn, for a series of different positions Tn, a pseudo 3D radiographic image of the part of the breast here based on a pseudo 3D phase contrast image using a tomosynthesis algorithm.

[0148] In practice, the movement of the given X-ray source at each point can be controlled by the control unit 51. For this purpose, the points Tn can be defined as input data of the human-machine interface by defining a number of points Tn and defining a value in degrees between each point Tn or a total arc value in degrees (defining the trajectory of the total displacement of the given X-ray source along the source support), said control unit 51 being configured to calculate the position and spacing of each point Tn on the source support 62. Alternatively, these displacements can be carried out manually using, for example, an angular graduation defined on the source support 62.

[0149] Similarly, the apparatus 100 may also comprise a position adjustment device 64 of the source support 62 for adjusting a position of said source support 62 relative to the X-ray image detector 30, at least along the translation axis (z-axis).

[0150] Typically, this adjustment device 64 can operate in a similar manner to the position adjustment device 61 of the X-ray image detector 30.

[0151] In a preferred embodiment, the source support 62 is fixed along the x axis, parallel to the translation axis of the breast platform 20 and / or the compression tablet 22. Thus, to obtain the desired magnification, only the breast platform 20, the compression tablet 22, the wedge 110 and optionally the X-ray image detector 30 are movable by means of the movable supports 60, 61 described above.

[0152] Optionally, the apparatus 100 comprises a support 70 on which are mounted at least the breast platform 20, the compression tablet 22 and the X-ray image detector 30 and optionally the position adjustment device 64 of the source support 62. Typically here, this support 70 comprises a support 71, for example in the form of a translation rail oriented parallel to the translation axis of the compression tablet 22, that is to say vertically relative to the ground. On this rail 71 are mounted the breast platform 20, the compression tablet 22 via the movable support 60, the image detector 30 or the movable support 61 of the image detector 30 (if present), and optionally the position adjustment device of the source support if present.

[0153] As illustrated in [Fig. 1], the support 70 may also comprise a holding element 72 (for example a holding plate) oriented perpendicular to the rail 71 and making it possible to stabilize the apparatus 100.

[0154] Optionally, the apparatus 100 also comprises a device 80 for holding the support on the ground. In practice, this holding device 80 is fixed to the support 70 (here by means 72 of holding the support 70). In a preferred embodiment, the holding device 80 is fixed to the ground for example by means of feet, here distributed along the surface of the holding element 72. Advantageously, the device 80 also includes casters 81 so that the device can be easily moved.

[0155] As illustrated in [Fig.6], the second X-ray source 10b emits the second X-ray flux 11b propagating along a propagation axis Ab. The propagation axis Ab is here preferably oriented vertically and directed towards the ground in order to better secure the apparatus 100 and to reduce the radiation dose emitted outside the apparatus 100.

[0156] The second X-ray source 10b is a so-called microfocus source, which has a spot diameter Db (at the output of the second source 10b) of between 1 pm and 20 pm. The second X-ray source 10b is for example a source based on an X-ray tube comprising an anode and a cathode. Such a microfocus source is for example marketed by the company Hamamatsu. The second X-ray flux 11b is here emitted at energies of between 10 keV (corresponding to a wavelength of 0.12 nm) and 80 kV (corresponding to a wavelength of 0.015 nm), preferably between 20 keV and 80 keV for a cathode current greater than 100 pA. In general, the anode of the second X-ray source 10b comprises at least one heavy material, for example at least one of the following materials: copper, molybdenum, tungsten. In our example, the anode material is molybdenum.In this case, the second X-ray source 10b generates a continuous X-ray emission spectrum with an emission peak around 17 keV corresponding here to the emission lines of molybdenum, by applying a high voltage to the cathode between 40 kV and 80 kV, with a current intensity greater than 100pA and a power greater than 5W.

[0157] In the second imaging configuration, the second X-ray flux 11b, at the output of the second X-ray source 10b, has a power greater than or equal to 5 W and generally less than 100 W. The second X-ray source 10b also emits the second X-ray flux 11b in an emission cone, specific to this source 11b. Here, by emission cone, is meant a cone of revolution around a propagation axis Ab, having as generator the diameter Db of the emission spot and having an apex angle or opening angle at the output of the second X-ray source 10b. The emission cone represents the volume in which the second X-ray flux 11b propagates from the second X-ray source 10b towards a portion of the part of the patient's breast which is immobilized between the platform 20 and the compression tablet 22.In other words, the second flux 11b of X-rays at the output of the second source 10b of X-rays is divergent, and propagates along the emission cone of the second source 10b of X-rays.

[0158] Preferably, the total opening angle of the emission cone of the second X-ray source 10b is between 5 degrees and 45 degrees, and preferably between 10 degrees and 45 degrees.

[0159] The second X-ray flux 11b propagates in a free field at the output of the second X-ray source 10b towards the compression tablet 22 of the apparatus 100. The second X-ray flux 11b passes through the compression tablet 22, the portion of the breast part 1 as well as the breast platform 20. For this purpose, it is understood that the compression tablet 22 as well as the breast platform 20 are also transparent to the wavelength range emitted by the second X-ray source 10b.

[0160] It is noted that the second X-ray flux 11b has a second initial wavefront representing its propagation at the output of the second X-ray source 10b. This second X-ray flux 11b propagates in the direction of the patient's breast 1 which is held, as in the first imaging configuration, by the compression tablet 22 and the breast platform 20.

[0161] As illustrated in [Fig.6] or in [Fig.7], only a portion of the compressed breast is irradiated by the second X-ray flux 11b. This portion is included in the part of the breast which was irradiated by the first X-ray flux 11a described above. Thus, only this portion of the breast is included in the emission cone of the second X-ray flux 11b. In particular, the region targeted by the second X-ray flux 11b corresponds to an area identified as suspect and / or containing suspect breast microcalcifications in the absorption mammography image obtained in the first imaging configuration on the same device 100.

[0162] In the example of the microfocus source described above, the second X-ray source 10b is configured to irradiate the breast 1 for a time period of between 10 seconds and 120 seconds in order to have enough signal to determine the phase shift image which will be described below.

[0163] Here, in this example, the portion of the breast containing microcalcifications is irradiated for 35 seconds in order to have a good compromise between dose administered to the patient and quantity of signal acquired to determine the phase shift image.

[0164] The second X-ray source 10b is configured to irradiate the portion of the breast part containing the microcalcifications at an X-ray dose of, for example, 400 pSv and 650 pSv. Such a range makes it possible to limit the X-ray dose received by the patient in accordance with health and safety standards while providing enough signal to allow rapid acquisition of the phase shift image of the portion of the breast part 1 of the patient.

[0165] In this second embodiment, no optical element (other than the compression tablet 22 and the breast platform 20) is positioned on the optical path of the second flow 11b passing through the breast. Thus, the second flow 11b of X-rays passing through the breast propagating between the breast support 20 and the X-ray image detector 30 is in free-field propagation (i.e. it propagates in free space).

[0166] Using free-field propagation reduces the costs of the apparatus 100 used in the second imaging configuration because fewer components are required in the apparatus 100 used in this configuration. In addition, this facilitates the determination of the phase shift image.

[0167] In this second imaging configuration, the X-ray image detector 30 is arranged to capture the second X-ray flux 11b having passed through the breast 1 (here the portion of the part of the breast). It is understood that the second X-ray flux 11b captured by the X-ray image detector 30 has a wavefront, denoted in the following second transmitted wavefront, which represents a spatial distribution of the second X-ray flux 11b having passed through the breast 1.

[0168] The spatial distribution of the transmitted wavefront (captured by the X-ray image detector 30) of the second X-ray stream 11b corresponds to an interference signal (i.e. amplitude) having a phase shift between the initial wavefront of the second X-ray stream 11b emitted by the second X-ray source 10b and a wavefront of the X-ray stream 11b which has been modified during its passage through the patient's breast 1.

[0169] This spatial distribution of the transmitted wavefront which is captured by the X-ray image detector 30 corresponds to an interference signal (i.e. intensity).

[0170] This second flow 11b of X-rays is then analyzed by the processing unit 40 to determine a second image of the phase shift corresponding to the intensity image of the second flow 11b of X-rays having passed through the patient's breast.

[0171] [Fig.9] illustrates an example in sectional view of a second image of the phase shift Imgb of a portion of the compressed breast determined by the processing unit 40 from the second flow 11b of X-rays captured by the X-ray image detector 30. More precisely, [Fig.9] represents an intensity profile of the X-rays captured on the image detector 30 by a plurality of lines of pixels extending for example along the x axis. The portion of the breast analyzed is in this example the portion of the part of the breast having been irradiated by the X-rays from the second source 11b of X-rays.

[0172] As illustrated, the intensity image Imgb has a main curved part PSb, representing the intensity of the X beam passing through the sample framed by two edges PSb in which the intensity signal here has a hollow shape followed by a peak which correspond to the interference between the beam passing through the internal and external edges of the sample. These edges 6 are, in the following, called the enhanced edge effect.

[0173] As illustrated in [Fig.9], enhanced edge effects are visible in the intensity image. The refraction of the X-ray beam at the edges of the sample, where the lateral gradients of the X-ray phase are greatest, causes intensity variations which are used to obtain an enhancement of the internal and external contours (or edges) of the sample.

[0174] The observed edge enhancement can be interpreted more rigorously using the wave nature of X-rays and Fresnel diffraction theory. From this point of view, the intensity distribution on the image detector 30 is the result of the interference of waves obtaining a variable phase shift by passing through the sample under study. At the distance d2b, the intensity distribution, after transmission through the portion of the immobilized breast part, is described by a formula which, for a weakly absorbing part of the breast, can be written as follows:

[0175] I(x,y,z)=l+ Xz / 2ir A_± <e>(x,y,0)

[0176] where I is the intensity of the detected radiation, X is the wavelength of the X-rays and <e>(x,y) the background phase studied on which the two-dimensional Laplace operator A acts in the xy plane.

[0177] The measured intensity is not here a direct measurement of the phase, but rather the Laplacian of the phase of the wavefront, noted in the sequence transmitted wavefront, which represents a spatial distribution of the second flux 11b of X-rays transmitted through the portion of the part of the breast 1 immobilized.

[0178] In practice, in the second configuration of the apparatus 100, the two edges depend on the second optical magnification described above. Thus, it is understood that the second optical magnification of the apparatus 100 in the second configuration is suitable for viewing the edges of the sample in intensity. Indeed, the two PSb edges are visible only when the propagation distance to the detector 30 is sufficient and the diffraction operates in the Fresnel regime.

[0179] The processing unit 40 illustrated in [Fig.7] is at least connected to the X-ray image detector 30 described above. By connected, it is meant that the processing unit 40 is arranged to communicate with another element, for example, by being configured to transmit and / or receive data from this element (here for example by wire). Here, in this case, the processing unit 40 is configured to determine an image of the phase shift from the intensity image captured by the X-ray detector 30 in the second imaging configuration, this intensity image being representative of the wavefront of the second stream 11b of transmitted X-rays. In the second imaging configuration, the processing unit 40 is configured to reconstruct, from this intensity image Imgb with enhanced edges (or phase contrast image), a phase image of the portion of the part of the immobilized breast 1.

[0180] In practice, the processing unit 40 is configured to extract the Laplacian of the phase of the signal according to phase extraction techniques known to those skilled in the art, for example as described in the document Burvall, A., Lundstrôm, U., Takman, PA, Larsson, DH, & Hertz, HM (2011), “Phase retrieval in X-ray phase-contrast imaging suitable for tomography”.

[0181] The processing unit 40 is also configured to reconstruct a phase contrast image from the Laplacian of the phase of the signal. Here, this phase contrast image is a free-propagation phase contrast image obtained from the intensity image of the second X-ray flux 11b transmitted through the portion of the breast irradiated by the second X-ray flux 11b.

[0182] Of course, it should be noted that the main part PSb of the recorded signal can be analyzed and processed by the processing unit 40 to reconstruct an absorption image of the part of the breast as described in the first imaging configuration.

[0183] Of course, if the processing unit 40 also reconstructs an absorption image (as in the case of [Fig.9]), it can also determine the presence of spots in this latter image in a similar manner to the method used for the phase contrast image of the sample.

[0184] In the second imaging configuration, the particular arrangement of the apparatus 100, here in particular its second optical magnification, makes it possible to precisely visualize the enhanced edges (i.e. the secondary parts PSb) present in the intensity image Imgb. Indeed, for a second lower magnification (in particular less than 8), these edges are barely or weakly visible in the intensity image, as can be seen in [Fig. 4] associated with the first imaging configuration. As a result, the intensity X-ray image obtained with a magnification greater than or equal to 8 and less than 30, and preferably between 8 and 15, is much more precise and makes it possible to extract therefrom a high-contrast and highly spatially resolved phase contrast image.

[0185] [Fig. 10] shows, at the top, three X-ray images (10A, 10B, 10C) of a microcalcification in a portion of breast of different patients obtained by absorption (denoted Abs.), and, at the bottom, three X-ray images (10D, 10E, 10F) of the same microcalcifications of the same portions of breast obtained by phase contrast (denoted C. Ph.). Each column of images in [Fig. 10] corresponds to the same microcalcification of the same portion of breast of the same patient. The three columns of images in [Fig. 10] here correspond to different patients. The three absorption images 10A, 10B, 10C are obtained with the device 100 in the first configuration, for example with a magnification of 15. The phase contrast images 10D, 10E, 10F are obtained with the same device 100 in the second configuration with the same detector 30, for example with a magnification of 15. In this example, the same magnification is used in both imaging configurations but not the same source spot size: in the first configuration, for absorption images, the spot of the X-ray source 11a is 100p and in the second configuration for phase contrast images, the diameter of the source 11b is 10p. Each image makes it possible to visualize one or more elements 91, 92, 92, 94, 95 opaque to X-rays, for example breast microcalcifications. As illustrated in [Fig. 10], different objects are extracted from the phase contrast image and from the absorption image.

[0186] However, the comparison of the absorption and phase contrast images of [Fig. 10] shows for each case that the phase contrast image has better contrast and better resolution compared to the obtained absorption image. For example, in the pair of images (10A, 10D), an object 91 opaque to X-rays is detected in the absorption image 10A and it is observed in the phase contrast image 10D that the contours of this object 91 are irregular. In the example of the pair of images (10B, 10E), two objects 92, 93 opaque to X-rays are detected in the absorption image and it is observed in the phase contrast image that the contours of these two objects 92, 93 are regular in the shape of a lozenge or diamond.In the example of the pair of images on the right, two spots 94, 95 partially opaque to X-rays are detected in the absorption image and it is observed on the phase contrast image that these two spots 94, 95 are diffuse and have irregular contours, for example filamentary in shape for spot 95. In all cases, the phase contrast image is much sharper than the absorption image.

[0187] Typically these microcalcifications can then be classified into different classes, for example according to the morphology of the spots detected in the images described above. In particular, the detected spots are classified according to their shape which can be regular, for example round or diamond-shaped, or irregular, possibly presenting asperities or hollows or even filaments. The radiology practitioner or doctor can then associate such a shape of spot with a low risk of pathology or with a risk of specific pathology.

[0188] It is understood that the resolution and contrast of the phase contrast image being better than those of the absorption image, the detection and / or sorting from the phase contrast image is more precise and therefore makes it possible to obtain better results.

[0189] Typically, the contour detection algorithm may be based on at least one of the following algorithms: - segmentation using a histogram; - a Laplace algorithm; - a gradient algorithm, etc.

[0190] As illustrated in [Fig.10], different objects 91, 92..., 95 are extracted from the phase contrast image and the absorption image. Comparison of the absorption and phase contrast images of [Fig. 10] shows that the phase contrast image has better contrast and resolution compared to the obtained absorption image.

[0191] Typically these objects 91, 92..., 95 can then be classified into different classes, by the processing unit 40, for example according to the morphology of the objects detected in the images described above.

[0192] It is understood that since the resolution and contrast of the phase contrast image are better than those of the absorption image, the detection and / or sorting from the phase contrast image is more precise and therefore makes it possible to obtain better results.

[0193] Figures 11 to 14 illustrate a second embodiment of an apparatus 200 according to the present invention. The apparatus 200 comprises all the elements of the apparatus 100 described above. [Fig. 11] and [Fig. 12] schematically represent the apparatus 200 in the first imaging configuration. [Fig. 13] and [Fig. 14] schematically represent the apparatus 200 in the first imaging configuration.

[0194] Unlike the apparatus 100, the apparatus 200 comprises a mobile housing 90 associated with the support 70 and accommodating at least the source support, the first X-ray source 10a, the rail 71 described above, the X-ray image detector 30 and the various position and / or orientation adjustment devices described above. As can be seen in this figure, the breast platform 20 as well as the compression tablet 22 are outside the housing to allow the patient's breast 1 to be positioned in the apparatus 200.

[0195] As illustrated, the support 70 is fixed to an inner face of the housing 90, for example by means of screws. It is understood that in this case, the holding means 72 of the support 70 may correspond to an inner face of the housing 90 or be fixed to this same inner face of the housing 90.

[0196] Here, the holding device 80 is fixed to an outer face of the housing 90.

[0197] The housing 90 may include closable opening elements in order to access the various elements included in the housing 90, for maintenance reasons. Typically, the closable opening elements may be plates fixed by screws to the housing 90 or doors that are closable and / or held by screws.

[0198] In this embodiment, it can be seen that the screen 53 is an element external to the housing 90. Similarly, it is understood that the control unit 51 can be a computer positioned outside the housing 90 and having a screen 53 serving human-machine interface. Preferably, the screen 53 is positioned a few meters from the device 200 and placed behind a screen, for example made of leaded glass, to protect the operator from X-rays.

[0199] Method

[0200] An example of an X-ray imaging method 300 using absorption imaging and phase contrast imaging will be written using [Fig. 15].

[0201] The method illustrated in [Fig.15] is implemented in the apparatus 100 or the apparatus 200 described above.

[0202] First, the apparatus 100, 200 is placed in the first imaging configuration. For this purpose, the patient is placed in front of the apparatus 100, 200 so as to immobilize a portion of a breast 1 between the platform 20 and the compression tablet 22. The first X-ray source 10a, the platform 20, the compression tablet 22, the wedge 110 and the detector 30 are arranged as described above to be in the first imaging configuration, the apparatus 100, 200 having a first optical magnification greater than or equal to 1 and less than or equal to 2.

[0203] The method 300 then comprises a step of emitting Ela the first flux 11a of X-rays from the emission spot of the first source 10a of X-rays. As specified above, the emission spot of the first source 10a of X-rays has a diameter Da greater than or equal to 50 pm. The first flux 11a of X-rays is emitted towards the part of the breast 1 of the patient immobilized between the platform 20 and the compression tablet 22.

[0204] Here, the first flow 11a of X-rays propagates in a free field towards the part of the breast 1 of the immobilized patient.

[0205] The method 300 also comprises a step E2a of detecting a first image Imga of X-rays in absorption via the detector 30. As indicated previously, the detector 30 is spaced from the first source 10a of X-rays by a distance d2a ranging from 50 cm to 120 cm, preferably greater than or equal to 60 cm and less than or equal to 80 cm.

[0206] The X-ray image detector is in this step arranged to capture the first flow 11a of X-rays transmitted through the part of the breast 1 of the patient.

[0207] In the first imaging configuration, the portion of the breast 1 of the immobilized patient is positioned between the first X-ray source 10a and the image detector 30 so that the first intensity image or absorption image acquired has a first optical magnification greater than or equal to 1 and less than or equal to 2.

[0208] A first absorption image of a part of the patient's breast 1 is thus obtained.

[0209] The method 300 preferably comprises a processing step E3a of the absorption image acquired in the first imaging configuration to determine a portion of the part of the breast 1 of the patient to be analyzed with a higher magnification in the second phase contrast imaging configuration. For example, this part of the breast contains a suspected focus of microcalcifications.

[0210] Then, the apparatus 100, 200 is placed in the second imaging configuration. The breast portion 1 remains immobilized between the platform 20 and the compression tablet 22 of the same apparatus 100, 200. The second X-ray source 10b, the platform 20, the compression tablet 22, the wedge 110 and the detector 30 are arranged as described above to be in the second imaging configuration, the apparatus 100, 200 having a second optical magnification greater than or equal to 8 and less than or equal to 30, preferably between 8 and 20, and even better between 8 and 15.

[0211] The method 300 then comprises a step of emitting Elb the second X-ray flux 11b from the emission spot of the second X-ray source 10b. As specified above, the emission spot of the second X-ray source 10b has a diameter Db of between 1 pm and 20 pm. The second X-ray flux 11b is emitted towards a portion containing microcalcifications of the part of the breast 1 of the patient immobilized between the platform 20 and the compression tablet 22.

[0212] Here, the second flow 11b of X-rays propagates in free field towards the portion of the breast part 1 of the immobilized patient.

[0213] The method 300 also comprises a step E2b of detecting a second image Imgb of X-rays in intensity via the detector 30. As indicated previously, the detector 30 is spaced from the second source 10b of X-rays by a distance d2b greater than or equal to 80 cm and less than or equal to 1.7 m and preferably between 80 cm and 1.5 m.

[0214] The X-ray image detector is in this step arranged to capture the second flow 11b of X-rays transmitted through the portion of the breast part 1 of the patient.

[0215] In the second imaging configuration, the portion of the breast 1 of the immobilized patient is positioned between the second X-ray source 10b and the image detector 30 so that the second acquired intensity image Imgb has the second optical magnification greater than or equal to 8 and less than 20, preferably between 8 and 15 to obtain better performance in terms of contrast and spatial resolution.

[0216] The method 300 also comprises a step E3b of processing the second image Imgb acquired by the detector 30 to determine a phase shift image and reconstruct, from this phase shift image, a phase contrast image of the portion of the breast part 1 of the immobilized patient.

[0217] The present invention is in no way limited to the embodiments described and shown, but those skilled in the art will be able to provide any variant in accordance with the invention.< / e> < / e>

Claims

1. Claims An X-ray mammography apparatus (100, 200) using two X-ray sources, said apparatus comprising at least: a breast platform (20) and a compression tablet (22) arranged to position and immobilize a portion of a breast (1) of a patient; a first mobile X-ray source (10a) arranged in a first imaging configuration for emitting, from an emission spot having a diameter greater than or equal to 50 pm, a first flux (11a) of X-rays towards a portion of the breast (1) of the patient, the portion of the breast being immobilized between the platform (20) and the compression tablet (22), a second mobile X-ray source (10b) arranged in a second imaging configuration for emitting, from an emission spot having a diameter between 1 pm and 20 pm, a second flux (11b) of X-rays, the second flux (11b) of X-rays being directed towards a portion of the portion of the breast of the immobilized patient,an X-ray image detector (30) arranged in the first imaging configuration for capturing the first X-ray stream (11a) transmitted through the breast portion and, respectively, in the second imaging configuration for capturing the second X-ray stream (11b) transmitted through the portion of the breast portion, the platform (20) and the compression tablet (22) being located between the X-ray image detector (30) and the first X-ray source (10a) in the first imaging configuration or, respectively, between the X-ray image detector (30) and the second X-ray source (10b) in the second imaging configuration, a source support (62) on which the first X-ray source (10a) and the second X-ray source (10b) are mounted,said source support being arranged to alternately position the first X-ray source (10a) in the first imaging configuration and the second X-ray source (10b) in the second imaging configuration, a control unit (51) configured to activate the first X-ray source (10a) in the first imaging configuration or the second X-ray source (10b) in the second imaging configuration, said activation of the first X-ray source or the second X-ray source being performed alternately, said apparatus (100, 200) having in the second imaging configuration a distance between the second X-ray source and the X-ray image detector (30) of between 80 cm and 1.6 m and an optical magnification greater than or equal to 8 and less than 20 and a processing unit (40) configured to determine a mammographic absorption image of the portion of the patient's breast from the first X-ray flux captured by the X-ray image detector (30) in the first imaging configuration and to reconstruct, from the second X-ray flux captured in the second imaging configuration, a phase contrast image of the portion of the patient's breast.

2. Apparatus (100, 200) according to claim 1, said apparatus (100, 200) has in the first imaging configuration a distance between the first X-ray source (10a) and the detector (30) of between 50 cm and 120 cm and an optical magnification greater than or equal to 1 and less than or equal to 2.

3. Apparatus according to claim 1 or claim 2, wherein, in the second imaging configuration, the second X-ray flux transmitted through the compression tablet (22) and the platform (20) propagates in free field towards the X-ray image detector (30).

4. Apparatus according to any one of claims 1 to 3, wherein the source support (62) comprises a rail and wherein the control unit is configured to move at least the first source (10a) and the second source (10b) along the rail of the source support so as to position: i) either the first X-ray source in the first imaging configuration, ii) or the second X-ray source in the second imaging configuration.

5. Apparatus according to any one of claims 1 to 4, wherein, in the first imaging configuration, the X-ray image detector (30) is positioned opposite the first X-ray source (11a), and in the second imaging configuration, the X-ray image detector (30) is positioned opposite the second X-ray source (11b).

6. Apparatus according to any one of claims 1 to 5, wherein, in the first imaging configuration, the first X-ray source is arranged to emit the first flux of X-rays in an emission cone around a propagation axis oriented vertically and directed towards the ground and, wherein, in the second imaging configuration, the second X-ray source is arranged to emit the second flux of X-rays in an emission cone around a propagation axis oriented vertically and directed towards the ground.

7. Apparatus according to any one of claims 1 to 6, wherein the X-ray image detector comprises an array of pixels having a first spatial dimension and a second spatial dimension, the first spatial dimension being greater than or equal to 10 cm and the second spatial dimension being greater than or equal to 10 cm.

8. Apparatus according to any one of claims 1 to 7, wherein the processing unit is configured to determine, by using an edge detection algorithm on said phase contrast image, the presence of an object in said phase contrast image and a morphology of each detected object.

9. Apparatus according to any one of claims 1 to 8, comprising at least one of the following elements: a support (70, 71) on which are mounted at least the source support (62), the breast platform (20) and the compression tablet (22), the X-ray image detector (30), a housing (90) associated with the support (70, 71), the housing (90) receiving at least the source support (62), the first X-ray source (10a) and the second X-ray source (10b), the breast platform (20) and the compression tablet (22), the X-ray image detector (30), a device (80, 81) for holding the support on the ground.

10. Apparatus according to any one of claims 1 to 9 comprising: an adjustment device (61, 61a, 61b) of the detector (30) configured to move the detector (30) in at least one spatial direction so as to adjust the distance between the detector (30) and the first X-ray source (10a) in the first imaging configuration or so as to adjust the distance between the detector (30) and the second X-ray source (10b) in the second imaging configuration, and / or the adjustment device (61, 61a, 61b) being adapted to adjust an orientation of the detector (30) in at least one rotation.

11. Apparatus according to any one of claims 1 to 10 comprising a position adjustment device (60, 60a, 60b) of the breast platform (20) and the compression tablet (22), the position adjustment device (60, 60a, 60b) being adapted to adjust a position of the breast platform and the compression tablet relative to the first X-ray source in the first imaging configuration or relative to the second X-ray source in the second imaging configuration.

12. Apparatus according to any one of claims 1 to 11, comprising a further device for adjusting the position and / or orientation of the source support (62) to adjust a position of said source support relative to the X-ray image detector (30) along at least one spatial direction, said at least one spatial direction corresponding to a translation of said source support (62) relative to the X-ray image detector and / or to adjust the orientation of the source support (62) relative to the X-ray image detector (30) according to at least one rotation angle.

13. Apparatus according to any one of claims 1 to 12, wherein, in the first imaging configuration, the control unit is configured to move the first X-ray source to different positions along the source support (62) and, for each position, determine an absorption mammographic image and a phase contrast image.

14. The apparatus of claim 13, wherein said apparatus is configured to reconstruct: a mammographic absorption image of a portion of the patient's breast by tomosynthesis from at least three absorption images of said portion of the patient's breast, the three absorption images being taken in three distinct orientations and / or a phase contrast image by tomosynthesis of the portion of the patient's breast from at least three phase contrast images of said portion of the patient's breast, the three phase contrast images being taken in three distinct orientations.

15. A method of X-ray mammography comprising the steps of: arranging an apparatus (100, 200) according to any one of claims 1 to 14 in a first imaging configuration, the first X-ray source (10a), the breast platform (20), the compression tablet (22), a wedge (110) and the detector (30) being arranged according to the first imaging configuration, a portion of a breast 1 of a patient being immobilized between the platform (20) and the compression tablet (22); emission (Ela) of a first flux (1 la) of X-rays from the emission spot of the first source (10a) of X-rays in free field and in the direction of the portion of the breast (1) of the patient immobilized between the platform (20) and the compression tablet (22), the emission spot of the first source (10a) of X-rays having a diameter greater than or equal to 50 pm; detection (E2a) of a first image (Imga) of X-rays in intensity via the detector (30) to obtain a first absorption image of a portion of the breast 1 of the patient;arrangement of the same apparatus (100, 200) in a second imaging configuration, the second X-ray source (10b), the breast platform (20), the compression tablet (22), the wedge (110) and the detector (30) being arranged according to the first imaging configuration, the part of a breast (1) of a patient being immobilized between the platform (20) and the compression tablet (22), said apparatus (100, 200) having in the second imaging configuration a distance between the second X-ray source (10b) and the X-ray image detector (30) of between 80 cm and 1.6 m and an optical magnification greater than or equal to 8 and less than 20;emission (Elb) of a second flux (11b) of X-rays from the emission spot of the second source (10b) of X-rays in free field and in the direction of a portion of the part of the breast (1) of the patient immobilized between the platform (20) and the compression tablet (22), the emission spot of the second source (10b) of X-rays having a diameter between 1 pm and 20 pm; detection (E2b) of a second image (Imgb) of X-rays in intensity via the detector (30); processing (E3b) of the second image (Imgb) to determine an image of the phase shift and reconstruct, from this image of the phase shift, an image by phase contrast of the portion of the part of the breast (1) of the patient.;

Images