RU147081U1 - DEVICE FOR VISUALIZING THE PATIENT'S BREAST OF THE PATIENT BY X-RAY RADIATION IN TOMOSYNTHESIS OR MAMMOGRAPHY MODE - Google Patents

Abstract

A device for imaging a patient’s mammary gland with x-ray radiation in a tomosynthesis or mammography mode, comprising an x-ray source located on one side of the mammary gland, and an X-ray image receiver located on the other side relative to the mammary gland, compression means for compressing and fixing the mammary gland, in which X-ray source and X-ray image receiver are rotatable as a whole with respect to compression a compressed and fixed mammary gland, characterized in that the device further comprises a collimator and a controlled diaphragm configured to form a narrow beam of x-ray radiation, while the x-ray image receiver is made in the form of a narrow linear two-coordinate position-sensitive x-ray detector, in which the height 20-40 times greater than the width, and with the possibility of moving along the arc discretely with stops along the compressed mammary gland with a step equal to the width at X-ray image pickup.

Description

The utility model relates to X-ray technology, namely to X-ray scanning digital devices, and can be used in medical institutions for the detection and diagnosis of breast diseases.

Currently, digital x-ray machines are widely used in medical diagnostics. They allow direct digital registration and image processing, followed by its output to a computer screen or solid media, see, for example, US patent application No. 2006/0222228, Mcl. G06K 9/00 publ. 10/05/2006.

However, the three-dimensional spatial resolution and contrast sensitivity of existing digital X-ray machines are either absent or do not meet the requirements of modern medicine.

A device for recording x-ray radiation containing a control unit and image transmission, a digital computer, an x-ray source with a collimator and a radiation sensor located on the guides, [RF patent No. 2343504, M. class., G01T 1/20, publ. 06/27/2008], in which the radiation sensor consists of a first device for converting x-ray radiation transmitted through the object under study into visible light radiation and a second device for converting visible light radiation into an electronic signal, the first conversion device — a polycrystalline sensor — is made from an x-ray sensitive scintillating material in the form of a plate, the thickness of which determines the required sensitivity to x-ray radiation, and the second device for converting constitutes a photodetector line, in which the photosensitive part coincides with the linear dimensions of the polycrystalline sensor, the polycrystalline sensor is optically coupled to a second device for conversion by means of a regular fiber optic cable with focons at both ends, and the linear dimensions of the foci coincide with the dimensions of the polycrystalline sensor on one side and the second device to convert from another.

The device described above allows you to increase the dynamic range of the x-ray receiver due to the refusal to use the ADC (analog-to-digital converter), and thereby increasing the diagnostic information content of the x-ray image.

However, the obtained images are overlapping shadow images of the studied object (organ) and do not provide three-dimensional information about the object (organ). In addition, when receiving a flat (2D) image, defects (pathologies) can be screened (shaded) below or above by lying objects (organs).

A device for detecting and diagnosing breast tumors is also known, which contains a source of penetrating radiation that illuminates the object under study, a diaphragm located in front of the object, and a two-coordinate position-sensitive detector located behind the object, equipped with a moving system relative to the object, and an information processing unit, [patent RF №2171627, M. cl., A61B 6/00, publ. August 10, 2001], in which the diaphragm is configured to form at least one narrow, slightly diverging beam of penetrating radiation in the direction of the object under study, and a two-coordinate position-sensitive detector is installed at such a distance from the object under study and has a spatial resolution that allows registration angular distribution of radiation intensity at small angles.

The device described above allows the use of small-angle coherent X-ray scattering to detect low-contrast small defects (pathologies) in the studied object (organ).

However, the obtained images do not provide information about the three-dimensional structure of the object (organ), three-dimensional structure of the defect (pathology).

A multimode system for obtaining x-ray images of the mammary gland, comprising a compression device for compressing and fixing the patient’s mammary gland for obtaining an x-ray image, assembling an x-ray tube, an x-ray image receiver, [US Patent Application No. 2009/0003519, M. C., A61B 6/04 publ. 01/01/2009], in which the aforementioned compression device, the X-ray tube and the said X-ray image receiver are mounted for movement to obtain a plurality of X-ray images in various modes and projections, and at an angle relative to each other mode and projection.

The system provides a multivariate combination of moving the x-ray tube and the receiver to obtain an x-ray image.

However, in this geometry, the location of the x-ray source at various angles to the stationary receiver of the x-ray image located under the mammary gland, it is impossible to use a screening raster, which leads to a deterioration in the contrast sensitivity of the diagnostic apparatus, and, consequently, to a deterioration of the diagnostic information about the object under study (organ )

Known diagnostic x-ray scanning digital apparatus containing sequentially located on the same optical axis of the x-ray source, a slit collimator and a linear multi-element x-ray detector, which are mounted on a single bracket mounted to rotate around the scan axis located in the plane of the slit of the collimator and the longitudinal axis of the linear multi-element detector [RF patent No. 23228217, M. cl., A61B 6/03, publ. December 20, 2007] in which the bracket is mounted at one end of the horseshoe-shaped truss mounted on the platform with the possibility of rotation in the rotation axes of the rotary mechanism, and the platform is placed on a vertical rack.

The device described above allows you to take pictures from various angles with arbitrary angles of inclination with respect to the patient’s body and, thereby, increase the information content of the pictures.

However, the images obtained do not provide information about the three-dimensional structure of the object (organ), three-dimensional location of the defect (pathology).

The closest to the claimed solution for the purpose of the technical nature and the achieved result when using is a device for imaging the patient’s mammary gland with x-ray radiation in tomosynthesis or mammography mode, containing an x-ray source located on one side of the mammary gland, and an x-ray image receiver located on the other side relative to the mammary gland, compression means for compressing and fixing the mammary gland, in which the x-ray source zlucheniya receiver and rotatable integrally with respect to compression plates, compressed and fixed breast [see. US patent application No. 2010/0135456, M. cl. H05G 1/60, dated 03/02/2010]. The x-ray image receiver further comprises a screening raster located on the side facing the x-ray source and focused on the focal point of the x-ray tube. A discrete x-ray image of the mammary gland is obtained at various positions of the x-ray tube relative to the mammary gland. Visual data is used for tomosynthesis. The device can also be used for mammography studies with a relatively large field of view, in which a radiation detector with dimensions of 24 × 29 cm is used.

The device described above allows, due to the establishment of a screening raster, to increase contrast sensitivity, which improves the diagnostic properties of the X-ray apparatus, especially in detecting pathologies in the early stages of diseases, however, the establishment of a screening raster also leads to an increase in the radiation load on the patient.

Therefore, the purpose of the proposed technical solution is to improve the diagnostic properties of the device by increasing spatial resolution, while reducing radiation exposure to the patient, by eliminating the use of a screening raster, as well as the use of a controlled diaphragm.

This goal is achieved by the fact that in the known device for imaging the patient’s mammary gland with x-ray radiation in tomosynthesis or mammography mode, containing an x-ray source located on one side of the mammary gland, and an x-ray image receiver located on the other side relative to the mammary gland, compression means for compression and fixation of the mammary gland, in which the x-ray source and the receiver are rotatable as one unit According to a useful model, the compression plate of a compressed and fixed mammary gland further comprises a collimator and a controlled diaphragm configured to form a narrow beam of x-ray radiation, wherein the x-ray image detector is made in the form of a narrow linear two-coordinate position-sensitive x-ray detector, in which height is 20-40 times greater than the width, and with the possibility of moving along the arc discretely with stops along the compressed mammary glands With a pitch equal to the width of the X-ray image receiver.

As can be seen from the statement of the essence of the claimed technical solution, it differs from the prototype and, therefore, is new.

The utility model is based on the task of improving the device for visualizing the patient’s mammary gland with x-ray radiation selectively in tomosynthesis mode or in mammography mode, in which, due to the pair, the x-ray source is an x-ray image receiver with the possibility of discrete rotation about the axis perpendicular to the optical axis of the pair on which an additional filter, a controllable diaphragm, a collimator and an X-ray image receiver, receiving entgenovskoe radiation, the collimator aperture and arranged to form a narrow X-ray beam, and X-ray image receiver is arranged to receive the narrow beam of X-radiation, a new technical result is achieved. It consists in the fact that the horizontal and vertical frequency-contrast characteristics (FMF) and the quantum detection efficiency (QED) remain the same due to the stop of the X-ray image receiver. This leads to an increase in spatial resolution, and the absence of a raster and the presence of a controlled diaphragm to reduce the radiation load on the patient.

A number of diagnostic x-ray devices are known (see the section "Description of the level of technology) that allows you to take pictures from various angles with arbitrary tilt angles with respect to the patient's body, in particular, the description of the invention to RF patent No. 23228217, which describes the kinematic diagram of the device, providing the opportunity such a multivariate placement of the x-ray source relative to the patient’s body. In this case, the device provides a spatial resolution of at least 5 pairs of lines / mm. Or, for example, PCT application WO 02/17790, which describes a device containing an x-ray source, a slit collimator and a linear multi-element x-ray detector that are sequentially mounted on a single axis, which are mounted on a single bracket mounted to rotate around a scan axis located in the plane of the slit of the collimator, and the longitudinal axis of the linear multi-element detector. The device allows, basically, to receive digital images with a vertically oriented body. The resolution of this device is lower than the previous one.

The claimed technical solution is fundamentally different from the known ones in that stopping the X-ray image receiver and irradiating it in a stationary state relative to the patient leads to the fact that horizontal and vertical (i.e., in the direction of movement and perpendicular to it) frequency-contrast (CCK) characteristics , and, consequently, spatial resolution, quantum detection efficiency (QED) and other characteristics remain the same, which means that the space is also higher Noah resolution more than 20 lp / mm.

The proposed solution is industrially applicable. The prototype was made and tested on the medical phantom RMI 156 of GAMMEX company (USA). On the image obtained with the help of the prototype, the image of the phantom RMI 156 shows all the elements up to 0.40 mm thick nylon fibers simulating fibrous and glandular tissue, 0.25 thick discs mm, simulating tumors, and point inclusions, simulating microcalcifications of 0.16 mm in size. It is known that not a single analog or digital mammograph in the world currently implements such parameters.

FIG. 1 diagram of the device.

A device for visualizing a patient’s mammary gland with x-ray radiation in a tomosynthesis or mammography mode, comprises an x-ray source 1 (shown in the diagram as a focal spot) located on one side of the mammary gland 2, and an X-ray image receiver 3 located on the other side relative to the mammary gland 2. For compression and fixation of the mammary gland 2, the device comprises a carrier plate 4 made with a radius of curvature corresponding to the movement of the X-ray image receiver 3, and compression 5, providing compression and fixation of the mammary gland 2. The x-ray source 1 and the receiver 3 are rotatable as a whole relative to the compression plates 4, 5, the compressed and fixed mammary gland 2 using a hard link connecting them 6. Coaxially with the x-ray receiver image 3 and the x-ray source 1 (its focal spot) additionally installed a collimator 7, a controlled diaphragm 8, configured to form a narrow beam of x-ray radiation, and a filter 9. The rotation of the entire system is carried out around the axis 10 of the perpendicular rigid connection 6. The X-ray image receiver 3 is made in the form of a narrow linear two-coordinate position-sensitive x-ray detector, in which the height is 20-40 times greater than the width, and with the possibility of moving along the arc discretely with stops along the compressed mammary gland in increments equal to the width of the X-ray image receiver.

The device operates as follows. A two-dimensional x-ray image of the mammary gland 2 is obtained using a rectangular X-ray image receiver 3 of size 8160 × 256 pixels (pixel size 27 × 27 μm ² ) sequentially irradiated and moved along the arc 11 with a radius of 650 mm. In the center of the arc 11 is the focal spot 1 of the x-ray tube (spot diameter 0.1 or 0.3 mm). The X-ray image receiver 3 moves discretely along the arc 11, stopping every 6.91 mm or 256 pixels (256 × 0.027 mm = 6.91 mm). At the moment of stop, the X-ray image receiver 3 is irradiated with X-ray radiation, which passes through one section of the patient’s mammary gland 2 with a given exposure, which, for example, is 4.5 cm for a compressed mammary gland, 0.112 sec. Data is transferred from the radiation receiver 3 to the computer during the movement of the X-ray image receiver 3. At the time of the movement of the X-ray image receiver 3, irradiation does not occur, which reduces the radiation load on the patient when performing diagnostic images. Stitching of individual fragments of the x-ray image is carried out by blurring the edges of the collimator 7 at the edges of the fragments, which occurs due to the finiteness of the focal spot size of the x-ray tube. Using a computer and a special mathematical algorithm, the result of the exposure is processed and transmitted to the display. The device provides images with a spatial resolution of at least 20 pairs of lines / mm.

For tomosynthesis using a special three-dimensional image program, the x-ray image receiver 3 together with the x-ray source 1 are installed so as to allow multiple x-ray images.

The operation of the device begins with a preliminary shot, in which the X-ray image receiver 3 moves from one extreme position to another, passing a distance of about 300 mm, thus allowing to determine the boundaries of the mammary gland 2 and the signal level under the mammary gland 2. The signal level under the mammary gland determines the value of the anode voltage and current of the tube. The edge of the mammary gland 2 determines the position of the X-ray image receiver 3 on the arc, from which the movement of the X-ray image receiver 3 begins and ends when a working picture is taken. Along the edge of the mammary gland 2, the movement of the diaphragm 8 is adjusted so that radiation outside the mammary gland does not reach the x-ray image receiver 3.

Depending on the parameters of the mammary gland and binning of the X-ray image receiver 3, the voltage at the anode of the X-ray tube and the tube current (not shown) are selected for the preliminary image, the thickness of the additional filter 9, the exposure and the resolution of irradiation are set, the size of the aperture window 8 is set. For example , for compressed mammary gland up to a thickness of 4.5 cm, binning 8 × 8 is selected, the anode voltage on the x-ray tube with a molybdenum anode is set Ua = 30 kV, the current in the tube is 30 mA, the exposure time is 8 ms, then the thickness of the additional filter is 0.5 mm from aluminum, the resolution of the irradiation is 6.91 mm, the size of the aperture window reduced to the input plane of the X-ray image receiver is 22 cm. The X-ray image receiver together with the X-ray source is installed in such a way as to allow multiple X-ray generation images for the synthesis of three-dimensional images (tomosynthesis).

When performing a preliminary picture of the mammary gland 2, the X-ray image receiver 3 moves relative to the mammary gland 2, with stops through certain sections of the path, for example, 6.91 mm. Each section is irradiated in accordance with the exposure, for example, 0.24 mA s with fixing the result of irradiation.

After obtaining and analyzing the preliminary image, determining the parameters of the working images for tomosynthesis, for example, three-dimensional image (tomography), the voltage on the x-ray tube is set to Ua = 30 kV, the tube current is 30 mA, the additional filtering parameters are 0.5 mm Al, the initial and final position detector 23 mm and 267 mm, respectively, the dependence of the movement of the diaphragm in tabular form is entered into the computer, the number of projections 17 and the angle of tomography 45 °, the discrete angle in tabular form entered into the computer.

After receiving 17 images (projections), for example, using a special mathematical algorithm on a computer, a three-dimensional x-ray image of the mammary gland is calculated.

The ability to complete irradiation strictly outside the breast reduces the radiation load on the patient. In addition, it provides protection for the X-ray image receiver, since it eliminates the penetration of X-ray radiation passing by the mammary gland 2 directly onto the receiver 3, protecting its semiconductors and phosphors from radiation, and reduces the irradiation of the structural elements of the device.

As can be seen from the presentation of the essence of the claimed technical solution and an example of its implementation, it allows you to get working pictures of the mammary gland with more than 4 times high spatial resolution and with a significantly lower radiation load on the patient.

Claims (1)

A device for imaging a patient’s mammary gland with x-ray radiation in a tomosynthesis or mammography mode, comprising an x-ray source located on one side of the mammary gland, and an X-ray image receiver located on the other side relative to the mammary gland, compression means for compressing and fixing the mammary gland, in which X-ray source and X-ray image receiver are rotatable as a whole with respect to compression a compressed and fixed mammary gland, characterized in that the device further comprises a collimator and a controlled diaphragm configured to form a narrow beam of x-ray radiation, while the x-ray image receiver is made in the form of a narrow linear two-coordinate position-sensitive x-ray detector, in which the height 20-40 times greater than the width, and with the possibility of moving along the arc discretely with stops along the compressed mammary gland with a step equal to the width at X-ray image pickup.

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