Methods and systems for dynamic collimation

Abstract

The present invention is entitled methods and systems for dynamic collimation. The present invention provides methods and systems for dynamic collimation adjustment during various X-ray imaging and image-guided procedures. In one example, the collimation of an X-ray mammography system is adjusted based on a volume of interest and also based on a workflow step of an imaging procedure. For example, before target selection, the collimation can be adjusted to illuminate a larger volume of interest and X-ray system acquisition parameters, and thus illuminate a larger area of ​​the detector; and after selecting target coordinates (e.g., for an interventional procedure), the collimation can be adjusted to illuminate a reduced volume of interest based on the selected target and X-ray system acquisition parameters, and thus illuminate a smaller area of ​​the detector.

Description

Technical Field

[0001] Embodiments of the subject matter disclosed herein relate to X-ray mammography systems, and more particularly, to dynamic collimator adjustment during mammography and biopsy procedures performed with X-ray mammography systems. Background Art

[0002] Mammography is an X-ray imaging procedure for detecting one or more tumors of the breast. Based on mammographic imaging, a breast biopsy procedure can be performed to obtain a biopsy sample of the breast tissue of interest for further analysis. Both mammography procedures and biopsy procedures can be performed using an X-ray mammography system. Before imaging with a mammography system, the breast is compressed between a compression plate and a detector. Then, radiation from an X-ray source is directed to the compressed breast, and a projection image is obtained at the detector. The projection image is reconstructed via image processing to obtain an X-ray mammographic image. When mammography is used for routine screening, each breast is imaged in two different views, specifically a head-foot position (CC) view and a medial-lateral oblique position (MLO) view. In addition to mammographic imaging, an X-ray mammography system can also be used to perform a digital breast tomosynthesis (DBT) procedure, in which the compressed breast is scanned at various angles and multiple cross-sectional images are reconstructed. DBT can also be used for screening purposes to obtain a clearer view of breast tissue. In addition to this, diagnostic imaging can be performed with an X-ray mammography system when necessary, in which additional images of the area of ​​interest are obtained by mammography or DBT to detect abnormalities and evaluate the initial diagnosis. DBT images can also be used in interventional procedures, such as DBT-guided biopsy procedures. In addition, follow-up imaging procedures, such as contrast-enhanced spectral mammography (CESM), can be performed with an X-ray mammography system to assess the progression of the disease in response to treatment.

[0003] X-ray mammography systems can include collimators to adjust the area on the detector that the X-ray radiation rays impinge. Typically, the area to be irradiated can be determined based on compression paddle size, breast support, application type (e.g., DBT vs. CESM), and user-selected settings. Summary of the invention

[0004] In one embodiment, a method for an X-ray system includes: during an imaging procedure performed using the X-ray system, adjusting collimation based on a workflow step of the imaging procedure to image a corresponding volume of interest. In this way, by adjusting collimation based on the workflow step to irradiate the volume of interest, the irradiation amount can be adjusted based on imaging needs. Therefore, visible artifacts in the image can be reduced. In addition, by focusing on the imaging needs of the workflow step, faster image reconstruction can be achieved with reduced radiation exposure to the patient. Therefore, imaging quality and efficiency can be improved, and patient care can be improved.

[0005] It should be understood that the above brief description is provided to introduce in a simplified form selected concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is solely defined by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The present disclosure will be better understood by reading the following description of non-limiting embodiments with reference to the accompanying drawings, in which:

[0007] Figure 1A is a schematic diagram of a mammography system for performing one or more imaging procedures according to one embodiment of the present disclosure;

[0008] Figure 1B According to one embodiment of the present disclosure, Figure 1A A schematic diagram of a biopsy device for use with a mammographic system;

[0009] Figure 2A is a high-level flow chart illustrating a method for alignment during a DBT-guided biopsy procedure according to one embodiment of the present disclosure;

[0010] Figure 2B yes Figure 2A Continuation of ;

[0011] Figure 2C is a high-level flow chart illustrating a method for determining a volume of interest to adjust collimation according to one embodiment of the present disclosure;

[0012] Figure 3A is a schematic diagram of dynamic lateral collimation according to one embodiment of the present disclosure;

[0013] Figure 3B is a schematic diagram of dynamic post-collimation according to one embodiment of the present disclosure;

[0014] Figure 3C is another schematic diagram of dynamic post-collimation according to an embodiment of the present disclosure;

[0015] Figure 3D A schematic diagram showing exemplary collimation at different X-ray source angular positions prior to target selection according to one embodiment of the present disclosure;

[0016] Figure 4A , Figure 4B and Figure 4Cshows a three-dimensional illustration of dynamic collimation according to one embodiment of the present disclosure, including corresponding illumination areas at three different X-ray source angular positions;

[0017] Figure 5A , Figure 5B and Figure 5C shows another exemplary three-dimensional illustration of dynamic collimation according to an embodiment of the present disclosure, including corresponding illumination areas at three different X-ray source angular positions;

[0018] Figure 6 shows a three-dimensional illustration of dynamic post-collimation according to one embodiment of the present disclosure;

[0019] Figure 7 is a high-level flow chart showing a method for performing dynamic collimation during one or more of a stereotactic-guided biopsy and a CESM-guided biopsy according to one embodiment of the present disclosure;

[0020] Fig. 8A is a schematic diagram of dynamic lateral collimation during one or more of a stereotactic-guided biopsy and a CESM-guided biopsy according to one embodiment of the present disclosure;

[0021] Figure 8B is a schematic diagram of dynamic post-collimation during one or more of a stereotactic-guided biopsy and a CESM-guided biopsy according to one embodiment of the present disclosure;

[0022] Figure 8C is another schematic diagram of dynamic post-collimation during one or more of a stereotactic-guided biopsy and a CESM-guided biopsy according to an embodiment of the present disclosure;

[0023] Fig. 9 A set of exemplary mammograms showing reduced imaging artifacts due to the dynamic collimation performed according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0024] The following description relates to a method for use in an X-ray mammography system such as Figure 1A The X-ray mammography system can be used to perform digital mammography procedures, digital breast tomosynthesis (DBT) procedures, contrast enhanced spectral mammography (CESM) procedures, and interventional procedures such as stereotactic guided biopsy, CESM guided biopsy, and DBT guided biopsy. Figure 1B. During any mammography procedure, the breast is compressed with compression paddles in order to position the breast for imaging. During imaging using an X-ray mammography system, radiation from an X-ray source is directed to an imaging volume that includes the compressed breast, and a projection image of the breast is obtained at a detector. The X-ray mammography system includes a collimator to adjust the field of view of the X-ray system and thereby adjust the irradiated portion of the compressed breast. Thus, the amount of radiation to which the patient is exposed is based on the collimation performed with the collimator. In addition, imaging requirements may change during a procedure.

[0025] exist Figure 2A and Figure 2B An exemplary method for dynamic collimation is discussed in which collimation is adjusted based on imaging requirements during a procedure performed with an X-ray mammography system. In particular, dynamic collimation adjustment during DBT-guided biopsy is demonstrated. For example, prior to selecting a target for biopsy, collimation may be adjusted to provide a larger field of view to obtain a view for positioning and target identification. In response to a user selecting a target, collimation may be adjusted to limit irradiation to a volume of interest determined based on the target selection. Thus, the area to be irradiated on the detector determined by the collimation is based on the volume of interest calculated based on the target selection. Additionally, during DBT acquisition, the X-ray source is rotated within an angular range of the X-ray system to obtain multiple images at multiple angles within the angular range. The collimation may be further adjusted based on the rotation angle of the X-ray tube during DBT acquisition. Thus, at each angular position of the X-ray tube, the collimation is adjusted. Thus, the area to be irradiated on the detector changes at each angular position of the X-ray source. Among other things, the volume of interest is based on breast thickness and compression paddle parameters.

[0026] Collimation adjustment is referred to as dynamic collimation, where the collimation is changed so that the area to be irradiated on the detector is changed based on one or more of the volume of interest and the angular position of the x-ray source. Dynamic collimation can be implemented during a single acquisition procedure (such as during a tomosynthesis acquisition), where at each goniometric position, the collimation and the detector area to be irradiated are changed to image the volume of interest. In addition, dynamic collimation can be implemented at different workflow steps during an imaging procedure (e.g., before and after target selection or region of interest selection), where the collimation is changed to image different volumes of interest according to the workflow step. Furthermore, dynamic collimation can be implemented in one or more of a screening procedure, a diagnostic procedure, and an interventional procedure performed with a mammography system as discussed further below.

[0027] In some embodiments, during an image-guided interventional procedure, before selecting a target, a first tomosynthesis scan of a compressed breast may be performed using a first collimation at a plurality of angular positions of an X-ray source of an X-ray system, and a first set of images may be reconstructed based on the first tomosynthesis scan data. Additionally, in response to selecting a target from the first set of images, a second tomosynthesis scan of the compressed breast may be performed using a second collimation at a plurality of angular positions of the X-ray system, and a second set of images may be reconstructed based on the first tomosynthesis scan data. The first collimation may be based on a larger volume of interest; and the second collimation may be based on a reduced volume of interest. The first collimation may also be based on a corresponding X-ray source angle measurement. The first collimation is adjusted to illuminate a corresponding larger area on a detector of the X-ray system at each of the plurality of angular positions. The second collimation is also based on a corresponding X-ray source angle measurement. The second collimation is adjusted to illuminate a corresponding reduced area on the detector at each of the plurality of angular positions. Additionally, each of the larger area and the reduced area is changed at each angular position by adjusting one or more of a lateral leaf position and a posterior leaf position of the collimator at each angular position. Furthermore, a first average detector area illuminated during a first tomosynthesis scan may be greater than a second average detector area illuminated during a second tomosynthesis scan.

[0028] In this way, by adjusting the collimation differently at different workflow steps (e.g., before target selection and after target selection), the total area to be irradiated can be reduced. This in turn results in reduced radiation exposure to the patient while improving the resolution of the volume of interest. An example high-level flowchart showing the process of determining a volume of interest is shown in Figure 2C An exemplary schematic diagram of dynamic collimation adjustment during DBT acquisition after selecting a biopsy target is shown in FIG. 3A to FIG. 3C In addition, Figure 3D An exemplary schematic diagram of collimation before target selection is shown, wherein the collimation is adjusted so that the area irradiated on the detector changes for each X-ray source goniometer during DBT acquisition in order to image a larger volume of interest. A three-dimensional illustration of the volume of interest and area to be irradiated at different angular positions of the X-ray tube during DBT acquisition after target selection is shown in FIG. 4A to FIG. 4C In addition, as the breast thickness decreases, for the same angular position of the X-ray tube, the area to be irradiated decreases, e.g. FIG. 5A to FIG. 5C In addition, Figure 6 An exemplary three-dimensional illustration of post-collimation adjustment and a side view of the area to be irradiated are shown. An exemplary method for dynamically changing the detector area to be irradiated for stereotactic guided biopsy and CESM guided biopsy is shown in Figure 7An exemplary illustration of lateral collimation adjustment of the CC view that may be utilized during stereotactic-guided biopsy and / or CESM-guided biopsy following biopsy target selection is provided in Fig. 8A The rear collimation adjustment for different breast thickness is shown in Figure 8B and Figure 8C During image-guided biopsy procedures (including DBT-guided biopsy, stereotactic-guided biopsy, CESM-guided biopsy, contrast-enhanced DBT (CE-DBT)-guided biopsy) utilizing an X-ray mammography system, by dynamically changing the detector area to be irradiated based on the volume of interest and X-ray source goniometrics after target selection, imaging artifacts due to accessories such as biopsy devices, biopsy needles, etc. can be reduced as the collimated X-ray beam is confined to a reduced volume of interest. Fig. 9 An exemplary reduction in imaging artifacts is demonstrated using exemplary scan images.

[0029] See also Figure 1A , a mammography system 100 for performing a mammography procedure according to an exemplary embodiment is shown, which includes an X-ray system 10. The X-ray system 10 may be a tomosynthesis system, such as a digital breast tomosynthesis ("DBT") system, and may be used to perform one or more procedures, including digital tomosynthesis imaging and DBT-guided breast biopsy. Additionally, the X-ray system 10 may be used to perform one or more of a dual-energy CESM procedure, a contrast-enhanced DBT (CE-DBT) diagnostic procedure, and an interventional stereotactic procedure.

[0030] The X-ray system 10 includes a support structure 42 to which a radiation source 16, a radiation detector 18, and a collimator 20 are attached. The radiation source 16 is housed in a gantry 15 that is movably coupled to the support structure 42. Specifically, the gantry 15 can be mounted to the support structure 42 so that the gantry 15 including the radiation source 16 can rotate about an axis 58 relative to the radiation detector 18. The rotation angle range of the gantry 15 that houses the radiation source 16 indicates that the rotation in either direction is from a vertical axis perpendicular to the horizontal detection surface of the detector 18 until the desired angle. For example, the rotation angle range of the radiation source 16 can be -α to +α, where α can make the angular range a limited angular range of less than 360 degrees. An exemplary X-ray system can have an angular range of ±15 degrees, which can allow the gantry to rotate from -15 degrees to +15 degrees relative to the vertical axis (i.e., rotation of the radiation source). The angular range can vary according to manufacturing specifications. For example, the angular range of a DBT system may be approximately ±11 degrees to ±60 degrees, depending on manufacturing specifications.

[0031] The radiation source 16 is directed toward the volume or object to be imaged and is configured to emit radiation rays at a desired time and acquire one or more images. The radiation detector 18 is configured to receive the radiation rays via a detection surface 24. The detector 18 can be any of a variety of different detectors, such as an X-ray detector, a digital radiography detector, or a flat panel detector. The collimator 20 is disposed adjacent to the radiation source 16 and is configured to adjust the irradiation area of ​​the imaging object.

[0032] In some exemplary embodiments, the system 10 may also include a patient shield 36 mounted to the radiation source 16 via a mask rail 38 so that a body part (e.g., head) of the patient is not directly exposed to the radiation. The system 10 may also include a compression paddle 40 that may be capable of moving upward and downward relative to the support structure along a vertical axis 60. Thus, the compression paddle 40 may be adjusted to be positioned closer to the radiation detector 18 by moving the compression paddle 40 downward toward the detector 18, and the distance between the detector 18 and the compression paddle 40 may be increased by moving the compression paddle upward away from the detector along the vertical axis 60. The movement of the compression paddle 40 may be adjusted by a user via a compression paddle actuator (not shown) included in the X-ray system 10. The compression paddle 40 may hold a body part (such as a breast) in a suitable position against the surface 24 of the radiation detector 18. The compression paddle 40 may compress the body part and hold the body part stationary in a suitable position while optionally providing a hole to allow insertion of a biopsy needle, such as a core needle or a vacuum-assisted core needle. In this manner, compression paddles 40 can be used to compress a body part to reduce the thickness through which x-rays pass and help reduce movement of the body part due to patient movement. X-ray system 10 may also include a subject support (not shown) on which a body part may be positioned.

[0033] The mammography system 100 may also include a workstation 43 including a controller 44 including a memory and at least one processor. The controller 44 may be communicatively coupled to one or more components of the X-ray system 10, including one or more of the radiation source 16, the radiation detector 18, the compression paddle 40, and the biopsy device. In one exemplary embodiment, communication between the controller and the X-ray system 10 may occur via a wireless communication system. In other exemplary embodiments, the controller 44 may be in electrical communication with one or more components of the X-ray system via a cable 47. Additionally, in one exemplary embodiment, as shown in FIG. Figure 1AAs shown, the controller 44 is integrated into the workstation 43. In other exemplary embodiments, the controller 44 may be integrated into one or more of the various components of the system 10 disclosed above. In addition, the controller 44 may include processing circuitry that executes stored program logic, and may be any of a variety of computers, processors, controllers, or combinations thereof that are usable and compatible with various types of equipment and devices used in the X-ray system 10.

[0034] Workstation 43 may include radiation shielding 48 that protects an operator of system 10 from radiation rays emitted by radiation source 16. Workstation 43 may also include a display 50, keyboard 52, mouse 54, and / or other suitable user input devices that facilitate control of system 10 via user interface 56.

[0035] Through its processor and controller, the controller 44 can regulate the operation and function of the X-ray system 10. For example, the controller 44 can provide timing control regarding when the X-ray source 16 emits X-rays, and can also regulate how the detector 18 reads and transmits information or signals after the X-rays hit the detector 18, and how the X-ray source 16 and the detector 18 move relative to each other and relative to the body part. The controller 44 can provide collimation control, for example, by commanding a collimator actuator to adjust the amount of opening of the collimator by adjusting one or more of the lateral blades and the rear blades of the collimator 20 so as to irradiate the volume of the object to be imaged, thereby controlling the area to be irradiated on the detection surface 24. The controller 44 can also control the manner in which information (including images 42 and data acquired during operation) is processed, displayed, stored, and manipulated. The various processing steps performed by the controller 44 include receiving one or more signals from one or more sensors, receiving user input, evaluating the received signals / inputs, image processing, determining an imaging volume of interest (e.g., based on a user-selected region of interest, based on a user-selected b-target), commanding collimator adjustments during acquisition and at various workflow steps, adjusting one or more actuators of the X-ray system to control the operation of the X-ray system, and these processing steps may be provided by a set of instructions stored in a non-volatile memory of the processor. Information may also be stored in one or more non-volatile memories of the controller 44 for later retrieval and use.

[0036] In addition, as described above, the radiation detector 18 receives radiation rays emitted by the radiation source 16. Specifically, during imaging using the X-ray system, a projection image of the imaged body part can be obtained at the detector 18. In some exemplary embodiments, data received by the radiation detector 18 (such as projection image data) can be transmitted from the radiation detector 18 to the controller 44 electronically and / or wirelessly. The controller 44 can then reconstruct one or more scanned images based on the projection image data, for example by implementing a reconstruction algorithm. The reconstructed image can be displayed to the user on the user interface 56 via the display screen 50.

[0037] The radiation source 16 together with the radiation detector 18 form part of an X-ray system 10 that provides X-ray images for the purpose of screening for abnormalities, diagnosis, dynamic imaging, and one or more of image-guided biopsies. For example, the X-ray system 10 can be operated in a mammography mode to screen for abnormalities. During mammography, the patient's breast is positioned and compressed between the detector 18 and the compression paddle 40. Therefore, the volume of the X-ray system 10 between the compression paddle 40 and the detector 18 is the imaging volume. The radiation source 16 then emits radiation rays onto the compressed breast, and a projection image of the breast is formed on the detector 18. The projection image can then be reconstructed by the controller 44 and displayed on the interface 50.

[0038] During mammography, the gantry 15 may be adjusted at different angles to obtain images of different orientations, such as a head-foot (CC) image and a medial-lateral oblique (MLO) image. For example, when imaging a CC view and an MLO view, the gantry 15, the compression paddle 40, and the detector 18 may rotate as a single unit about the axis 58. In other examples, the gantry 15 may rotate about the axis 58 while the compression paddle 40 and the detector 18 remain stationary.

[0039] In addition, the X-ray system 10 can be operated in a tomosynthesis mode for performing digital breast tomosynthesis (DBT). During tomosynthesis, the X-ray system 10 can be operated to direct low-dose radiation to the imaging volume (between the compression paddles 40 and the detector 18) at various angles within the angular range of the X-ray system 10. Specifically, during tomosynthesis, similar to mammography, the breast is compressed between the compression paddles 40 and the detector 18. The radiation source 16 is then rotated from -α degrees to +α degrees, and a plurality of projection images of the compressed breast are acquired at regular angular intervals within the angular range. For example, if the angular range of the X-ray system is ±15 degrees, the detector can capture 31 projection images approximately every degree of sweep during the angular sweep of the gantry. The plurality of projection images are then processed by the controller 44 to generate a plurality of DBT image slices. The processing may include applying one or more reconstruction algorithms to reconstruct a three-dimensional image of the breast.

[0040] In addition, the X-ray system can be configured to perform a DBT-guided biopsy procedure. Thus, in some exemplary embodiments, the system 10 can also include a biopsy device including a biopsy needle for extracting a tissue sample for further analysis. Figure 1B Displayed in.

[0041] Go to Figure 1B , showing a method that can be used with a mammography system such as Figure 1A Schematic diagram of a biopsy device 140 for use with a mammographic system 100 of the present invention. Figure 1A 1. The biopsy device 140 is described with reference to the mammography system 100 in FIG. The biopsy device 140 includes a biopsy table 155 positioned above the detector 18 of the X-ray system 10. In one example, the biopsy table 155 can be configured to slide above the detector 18. During the setting of the biopsy device 140, the user can remove the compression paddle 40 of the X-ray system 10 and slide the biopsy table 155 above the detector 18. When the biopsy device 140 is positioned on the X-ray system 10, a suitable compression paddle (not shown) for the biopsy, such as a horizontal approach biopsy paddle (without a hole) or a vertical approach biopsy paddle (with a hole), can be selected according to the type of biopsy and connected to the X-ray system 10.

[0042] A biopsy tool interface 160 having a biopsy tool display 162 may be coupled to the biopsy table 155 via a communication port 164. In one embodiment, the biopsy tool interface 160 may be communicatively coupled to the X-ray system controller 44, as indicated by the double-ended arrow 154, so that a user may be able to adjust the position of the X-ray system via the biopsy tool interface 160. In other embodiments, the biopsy tool interface 160 may be coupled to a biopsy device controller 150, which sends information to and receives information from the X-ray system controller 44 (as indicated by the double-ended arrow 152). In some other embodiments, adjustment and control of the biopsy device 140 may additionally or alternatively be performed by a biopsy device control module 159 of the X-ray system controller 44.

[0043] Biopsy device 140 includes a biopsy tool 170 that can be directly coupled to biopsy table 155. Biopsy tool 170 includes a robotic system that includes a trunk 172 to which a first arm 174 is attached. Biopsy tool 170 can also include a second arm 176 coupled to first arm 174 at one end and to a biopsy gun holder 180 at an opposite second end. Second arm 176 can pivot relative to first arm 174 to adjust the position of the biopsy gun holder. Figure 1BThe illustration in FIG. 1 shows a biopsy tool 170 configured for biopsy in a vertical approach. A vertical approach involves inserting a needle into the breast in a direction perpendicular to the horizontal plane of the compression paddle. Thus, during the setup of the biopsy device in a vertical approach, the biopsy gun holder 180 is positioned such that the longitudinal axis of the biopsy gun holder 180 along the length of the biopsy gun holder 180 is parallel to the Z-axis 141 and perpendicular to the horizontal surface 156 of the biopsy table 155.

[0044] The biopsy tool 170 can be adjusted to perform a biopsy in a horizontal approach, wherein the needle is inserted into the breast in a direction parallel to the compression paddle. During the setting of the biopsy device in a lateral approach, the second arm 176 can be pivoted 90 degrees via the knob 177 so that the longitudinal axis of the biopsy gun holder is perpendicular to the Z-axis 141 and parallel to the horizontal surface of the biopsy table 155.

[0045] The biopsy gun holder 180 can be used to mount the biopsy gun 184. In addition, the biopsy gun holder 180 can include a mechanical stop for adjusting the position of the biopsy needle 190. Specifically, during a biopsy, before the needle is inserted, the breast is positioned between a compression paddle (not shown) and the surface 156. In some examples, a breast pad can be positioned on the surface, the breast is positioned between the compression paddle and the pad and compressed by moving the compression paddle toward the surface 156. While the breast is positioned, a first set of target images is obtained by scanning the compressed breast with the X-ray system 10 at various angles within its angular range to identify the target for biopsy. The first set of target images can be a three-dimensional image (DBT image) or a two-dimensional full-field digital mammography image acquired and reconstructed by the X-ray system. The user can locate the area of ​​interest and identify the target location for biopsy by selecting the target location from the first set of images. The target location can be identified by the x-coordinate, y-coordinate, and z-coordinate within the DBT volume between the compression paddle and the biopsy table surface 156 or the pad (if used).

[0046] When a biopsy target location is selected, a second set of DBT images can be obtained, for example, after anesthesia and before needle insertion. In this way, DBT images can be acquired at different workflow steps during a DBT-guided biopsy. In addition, collimation can be adjusted at each workflow step to provide a first collimation based on a first, larger volume of interest for acquisition before target selection, and a second collimation based on a second, smaller volume of interest for acquisition after target selection. Details of adjusting collimation at different workflow steps during image acquisition are described below with respect to FIG. 2A to FIG. 2C , FIG. 3A to FIG. 3D , FIG. 4A to FIG. 4C , FIG. 5A to FIG. 5C , Figure 6 , Figure 7 and FIG. 8A to FIG. 8CFurther Discussion. In short, during any imaging procedure and / or image-guided interventional procedure (e.g., biopsy), prior to target selection, the collimator 20 may be commanded to provide a first collimation in which the collimated X-ray beam output from the collimator 20 irradiates a larger volume of the compressed breast to identify the target tissue portion and the location of the target tissue. For example, during a DBT acquisition, the area to be irradiated on the detection surface after traversing the larger volume of the compressed breast may be adjusted at each X-ray tube goniometer to include the larger volume prior to target selection. Specifically, even though the X-ray source field of view is large to help locate the breast, the area to be irradiated on the detector is not maintained at each goniometer, but is adjusted so as to include a larger volume of interest at each goniometer.

[0047] After target selection, the collimator 20 may be commanded to provide a second collimation, wherein at each angle of the x-ray source, the collimator 20 is adjusted to limit irradiation to a reduced volume of interest that includes the target (and thus the volume of the region of the breast that contains the target). In some examples, a margin volume may be added to the reduced volume of interest so as to image a slightly larger portion of the breast. It should be appreciated that the total volume of the breast irradiated after target selection (i.e., including the reduced volume and the margin volume) is less than the larger volume irradiated before target selection.

[0048] In addition, the collimator 20 is adjusted based on the X-ray tube angle measurement so that at each angle measurement, the collimated X-ray beam is limited to irradiating the reduced volume of interest. The collimator adjustment after target selection can be based on the corresponding area to be irradiated on the detector at each angle measurement. In this way, the area irradiated on the detector is dynamically adjusted to image the reduced volume of the breast after target selection. This reduces the radiation exposure of the patient in one or more post-target selection steps because the imaging area is reduced to the reduced volume of interest. In addition, by limiting the imaging portion to the reduced volume of interest, imaging artifacts caused by image capture of metal objects (e.g., portions from a biopsy device) are reduced. In addition, the time to reconstruct the image after target selection is reduced. In addition, during a CESM-guided biopsy procedure, imaging artifacts depend on the amount of scatter. By reducing the irradiated area, the amount of scatter can be reduced.

[0049] Additionally, based on the target position coordinates selected by the user, biopsy device controller 150 can adjust the position of the mechanical stop of biopsy gun holder 180 so that when the needle is inserted into the compressed breast via biopsy gun 184, movement of the needle stops when the needle tip reaches a desired position relative to the target position. Although this example illustrates adjusting the biopsy device via biopsy device controller 150, it should be understood that in some embodiments, X-ray system controller 44 can command control of biopsy device 140. In this manner, the depth position of the biopsy needle can be adjusted using biopsy gun 184 and biopsy gun holder 180 during a biopsy in a vertical approach mode.

[0050] In addition, the biopsy tool 170 may include a platform 173 and a guide rail 177. The trunk 172 of the biopsy tool 170 may be moved above the platform 173 parallel to the X-axis 143. The movement of the biopsy tool 170 above the platform 173 is indicated by the double-ended arrow 147. The movement of the trunk along the platform 173 may be regulated by the controller 150. Therefore, during a biopsy, the position of the biopsy gun and the gun holder may be adjusted in the direction of the X-axis so that the X-axis coordinate of the needle position is adjusted relative to the target position. In addition, the platform 173 may be moved in the direction of the Y-axis 142 along the guide rail 177. The movement of the biopsy tool 170 in the Y-axis direction is indicated by the double-ended arrow 148. Therefore, during a biopsy, the position of the biopsy gun and the gun holder may be adjusted in the direction of the Y-axis so that the Y-axis coordinate of the needle position is adjusted relative to the target position. In addition, the biopsy tool 170 may be moved upward and downward, as indicated by the double-ended arrow 149. For example, arm 174 may be movable in the direction of Z-axis 141 as indicated by arrow 149 to adjust the position of biopsy gun holder 180 (and thus biopsy gun 184 and biopsy needle 190) along Z-axis 141. Movement of the biopsy tool in the x-direction, y-direction, and z-direction may be regulated by controller 150. It should be understood that embodiments in which adjustment of the biopsy tool in one or more of the x-direction, y-direction, and z-direction is manually performed in addition to or as an alternative to adjustment by the controller are also within the scope of the present disclosure.

[0051] In summary, during a biopsy, before inserting the needle 190, when a target position is selected from a first set of target images obtained by the X-ray system, the controller (which may be the X-ray system controller 44 or the biopsy device controller 150) may adjust the position of the biopsy needle by adjusting the biopsy tool in the direction of the X-axis 147, in the direction of the Y-axis 148, and in the direction of the Z-axis 149, and adjust the position of the mechanical stop based on the target position coordinates, so that when the needle is inserted, the needle tip is at a desired position in the breast tissue relative to the target position.

[0052] In this manner, the robotic system of the biopsy tool 170 can be utilized to adjust the needle position and biopsy tool position based on the target position calculated from the image. Once the biopsy tool and biopsy gun are in the target position, the user / radiologist can drive the needle through the biopsy gun 184 until it reaches a mechanical stop. Once the needle is fully inserted, it is in the target position (i.e., a position where the notch of the needle is in a position within the tissue relative to the lesion to be punctured, but has not yet excised the lesion).

[0053] Once the needle is inserted, it is in the pre-fire position. During a DBT-guided biopsy, multiple pre-fire images can be obtained when the needle is in the pre-fire position. In one embodiment, the collimator 20 can be dynamically adjusted at each angulation of the X-ray source to irradiate a reduced volume of interest during the acquisition of multiple pre-fire images. The pre-fire images can be used to confirm the position of the biopsy needle (specifically, the needle tip) relative to the biopsy target. Since the reduced volume of interest is imaged, the pre-fire images can be reconstructed at a faster rate. In addition, the image of metal objects near the reduced volume is reduced.

[0054] When the biopsy needle position is confirmed based on the pre-firing image, the biopsy gun 184 can be deployed to fire the biopsy needle. For example, after the needle is fired (post-firing), multiple post-firing images can be obtained to evaluate the position of the needle's notch relative to the target. Subsequently, the target tissue can be extracted. After extraction, a post-biopsy clamp can be inserted at or near the biopsy site to mark the biopsy position. After extraction and insertion of the biopsy clamp, multiple post-clamp images can be obtained. In one embodiment, the collimator 20 can be adjusted to irradiate a reduced volume of interest during the post-firing image and / or post-clamp image. Since the reduced volume of interest is imaged, the post-firing image and / or post-clamp image can be reconstructed at a faster rate. Therefore, the entire biopsy procedure can be performed at a faster rate, thereby improving patient care and comfort.

[0055] Although the collimation adjustment is described herein with respect to a biopsy procedure, it should be understood that the collimation adjustment can be implemented for any other interventional or diagnostic procedure performed using an X-ray system, wherein at different workflow steps, the collimator is adjusted to adjust the area irradiated on the detector based on the corresponding volume of interest so as to limit the irradiation to the corresponding volume. An example interventional procedure may include a breast surgery procedure in which a hook wire is deployed and the target is a clamp. When assessing the hook wire position within the breast (e.g., after the hook wire is deployed), the collimation can be adjusted based on a target volume with a target area of ​​interest. Another example procedure may be an image-guided cryoablation procedure.

[0056] Details of the collimation adjustment are given below regarding FIG. 2A to FIG. 2C , FIG. 3A to FIG. 3D , FIG. 4A to FIG. 4C , FIG. 5A to FIG. 5C , Figure 6 , Figure 7 and FIG. 8A to FIG. 8C Give a description.

[0057] Go to Figure 2A , which shows a high-level flow chart illustrating the use of an X-ray imaging system (such as Figure 1A X-ray system 10 in Figure 1B Method 200 for adjusting collimation during a DBT-guided biopsy procedure of a biopsy device 140 in FIG. 200 may be performed by an image processing system such as Figure 1A The method 200 may be implemented by a controller 44 in the image processing system, an edge device connected to the image processing system, a cloud in communication with the image processing system, or any suitable combination thereof. Figure 1A and Figure 1B Although the method 200 is described with reference to systems and components of the present invention, it should be understood that the method 200 may be implemented with other systems and components without departing from the scope of the present disclosure.

[0058] Method 200 begins at 202. At 202, method 200 includes confirming whether the X-ray system is operating in a DBT-guided biopsy mode. In one example, the operating mode of the X-ray system can be determined based on an indication made by a user on a user interface of the X-ray system. For example, the controller can determine the operating mode based on the user launching an application interface corresponding to the operating mode (e.g., launching a DBT-guided biopsy interface). Therefore, in response to the user launching the DBT-guided biopsy interface, the DBT-guided biopsy mode can be confirmed. In another example, the operating mode can be determined based on a visual sensing system detecting the presence of one or more accessories associated with a DBT-guided biopsy procedure (such as a biopsy device positioned on a detector surface of the X-ray system). In this case, the application interface for DBT-guided biopsy can be automatically launched, and the controller can determine that the X-ray system is used for DBT-guided biopsy based on one or more of the indication from the visual sensing system and the launch of the DBT-guided biopsy interface.

[0059] If the DBT-guided biopsy mode is not confirmed, the answer at 202 is "no" and the method 200 proceeds to 203. At 203, the method 200 includes operating the X-ray system based on the mode indicated by the user. For example, the user-indicated mode can be a mammography mode, which can include a 2D screening mode, a 2D diagnostic mode, a DBT screening mode, a DBT diagnostic mode, a CESM diagnostic mode, a stereotactic-guided biopsy mode, and a CESM-guided biopsy mode, as well as a quality check mode. Figures 8A to 8CFurther described are exemplary methods for adjusting the collimation of an X-ray system during a CESM-guided biopsy mode or a stereotactic-guided biopsy mode.

[0060] If DBT-guided biopsy mode is confirmed, the answer at 202 is "yes" and method 200 proceeds to 204. At 204, method 200 includes confirming whether the breast is positioned for biopsy. This includes determining whether the breast is compressed between the compression paddle and the detector surface, and may include determining whether a pad is utilized to support the breast during compression. In one example, confirmation of breast positioning can be based on an indication from a user via a user interface of the x-ray system to initiate a first image acquisition. For example, when positioning the breast for biopsy, the user may initiate a first image acquisition to obtain one or more positioning views of the breast that may be used to identify a target for biopsy. In another example, confirmation of breast positioning can be based on an indication from a user via a user interface that breast positioning has been completed.

[0061] If the breast position for biopsy has not been confirmed (eg, while the user is in the process of adjusting the patient for biopsy, prior to positioning the patient, etc.), the answer at 204 is "no" and the controller continues to monitor the x-ray system for positioning confirmation.

[0062] If the breast location for biopsy is confirmed, the answer at 204 is yes and method 200 proceeds to 206 .

[0063] At 206, method 200 includes acquiring a first set of projection images using collimation adjusted to illuminate a larger volume of the breast. Specifically, the collimator is adjusted so that the detector field of view is at a first larger field of view covering a larger volume of the breast (e.g., the entire breast). In other words, the collimator blades are adjusted so that the X-ray beam is collimated to illuminate a larger volume of the breast, and therefore, for the larger volume of the breast, the detector area illuminated by the collimated X-ray beam after it passes through the breast tissue is larger. This results in a first larger detector field of view. The detector area is also referred to herein as a projection field of view. The collimation obtained when the collimator is adjusted to illuminate a larger volume of the breast as discussed above can be referred to as a first collimation. Adjusting the collimator blades can include adjusting the lateral blades as well as the rear blades. It can be noted that the first image acquisition with the first collimation is obtained before selecting a target for biopsy and is used to identify the target and specify the target coordinates for the biopsy.

[0064] Acquiring a first set of projection images using a first collimation includes obtaining one or more 2D scout projection images and a plurality of DBT target projection images at 207. For example, the one or more 2D scout views may be obtained using an X-ray tube at an intermediate position where a vertical axis of the X-ray tube (such as Figure 1A The vertical axis 60 in the image is perpendicular to the top detecting surface of the detector. The collimator can be adjusted to illuminate a larger volume of the breast.

[0065] In addition, multiple DBT target projection images can be obtained using a collimator that is adjusted to illuminate a larger portion of the breast. During the acquisition of multiple DBT target images, the X-ray tube can be rotated within the angular range of the X-ray tube, and multiple images can be acquired at each of a plurality of angles within the angular range. In one example, at each angulation of the X-ray tube, before selecting a target for biopsy, the collimator can be adjusted so that the area illuminated on the detector changes at each angulation of the X-ray tube to image a larger volume of interest. In this manner for positioning and target identification, the volume of the imaged breast is larger to facilitate target identification and patient positioning. In addition, by adjusting the collimation (i.e., by implementing dynamic collimation) to include the entire larger volume of interest at each angulation, imaging resolution is improved. An example illustration of the first collimation and irradiated detector area prior to target selection is shown in FIG. Figure 3D Shown in.

[0066] Next, at 208, method 200 includes reconstructing a first set of images from the projection images, and displaying the first set of images. The first set of images is reconstructed from one or more 2D scout projection images and a plurality of DBT target projection images. Thus, the first set of images includes one or more 2D images of the breast (reconstructed from the one or more 2D scout projection images) and a three-dimensional image of the breast, the three-dimensional image including a plurality of DBT image slices (reconstructed from the plurality of DBT target projection images). The first set of images may be displayed on a user interface. A user may utilize the first set of images to identify a target for biopsy. For example, a user may view one or more 2D scout images. Additionally, a user may view a plurality of DBT image slices one by one to identify a target plane and identify a target. The target may be identified by a user selecting the target on one of the plurality of DBT image slices.

[0067] Continuing to 210, method 200 includes determining whether a target is received at a controller. For example, the controller may determine whether a target location for biopsy is identified based on a user selection of a target on one or more of the 2D positioning image and a plurality of DBT image slices. The target location for biopsy may be within a region of interest and may be selected by a user via an X-ray system user interface and / or a biopsy tool interface based on identifying an abnormality from a first set of reconstructed images. The abnormality may be an indication of breast cancer and may include one or more of lesions, microcalcifications, distortions of tissue structure, and any deviations from normal breast anatomy that may be indicative of breast cancer. For example, a user may select a target by highlighting the target location. Alternatively, a target location may be referred to herein as a target position or simply a target.

[0068] If the target is not identified, the answer at 210 is "no" and method 200 proceeds to 211. At 211, the controller may prompt the user to identify the target and the method may return to 210 to determine if the target has been selected.

[0069] If the target is identified by the user / received at the controller, the answer at 210 is yes and method 200 proceeds to 212 .

[0070] At 212, method 200 includes determining, for each goniometric measurement of the x-ray source, a corresponding detector area to be irradiated based on the reduced volume of interest and the corresponding x-ray source goniometric measurement. The reduced volume of interest encompasses the target and is therefore determined based on the selected target biopsy coordinates, a breast size (e.g., thickness), and one or more compression paddle parameters (e.g., compression paddle hole size and position). Additionally, in one example, the reduced volume of interest can include a margin volume surrounding the biopsy volume including the biopsy target. In this example, the margin volume is taken into account to calculate the detector area to be irradiated. Further details of determining the reduced volume of interest are provided below in Figure 2C discussed in.

[0071] Go to Figure 2C , shows a high-level flow chart illustrating the use of an X-ray mammography system (such as Figure 1A A method 280 for determining a reduced volume of interest after target selection during an image-guided interventional procedure (such as a DBT-guided biopsy procedure) performed by an X-ray system 10 in a CT image processing system. The method 280 may be performed by an image processing system (such as Figure 1A It may be implemented by a controller 44 in the image processing system, an edge device connected to the image processing system, a cloud in communication with the image processing system, or any suitable combination thereof.

[0072] The method 280 starts at 282. At 282, the method 280 includes acquiring / measuring / estimating target coordinates, breast dimensions, and one or more compression paddle parameters. The target coordinates may be determined based on a user selection of a target as discussed above. While the above example describes a target for a biopsy procedure, it should be understood that the target may be a region of interest selected by a user to better visualize the selected region of interest, such as during a screening or diagnostic imaging procedure. In this case, the volume of interest may be based on the coordinates of the selected region of interest, the breast dimensions, and the x-ray tube angulation (where the imaging volume is irradiated).

[0073] Breast size can include breast thickness. Breast thickness can be compressed breast thickness, and in one example, can be based on a user indication. In another example, compressed breast thickness can be based on the position of a compression paddle. For example, a position sensor coupled to a compression paddle can be used to determine where on the Z axis the compression paddle stops. In yet another example, compressed breast thickness can be based on input from a visual sensor. In yet another example, breast size (including breast thickness) can be obtained from a sensor-based compression paddle that measures breast size (e.g., to determine a desired compression pressure).

[0074] Additionally, the one or more compression paddle parameters may include a compression paddle hole. For example, during a vertical biopsy approach, a user may enter the breast through the one or more paddle holes, and thus the reduced volume of interest may be based on the one or more compression paddle hole sizes and positions relative to the target.

[0075] Next, method 280 proceeds to 284. At 284, method 280 includes determining a reduced volume of interest based on the target coordinates, the breast thickness, and one or more compression paddle parameters. In one embodiment, the reduced volume of interest can be calculated as a function of the biopsy volume (based on the target location, the size of the biopsy target, and the selected biopsy needle), the compressed breast thickness, and the paddle hole parameters (e.g., size and position) of the selected paddle. In another embodiment, the reduced volume can be calculated based on a radiologist's selection of the reduced volume of interest via a user interface, for example. In yet other embodiments, the volume of interest can be selected to image only the useful breast volume, and thus, other patient body parts, such as the contralateral breast, abdomen, etc., can be excluded from the selected volume of interest.

[0076] When the reduced volume of interest is determined, method 280 returns to Figure 2A Step 212 is performed to determine the corresponding area to be illuminated on the detector.

[0077] For a given reduced volume of interest, the detector area to be irradiated depends on the X-ray tube goniometrics. For example, once the target is identified and received by the controller, the reduced volume of interest is determined based on the target coordinates, breast thickness, and compression paddle hole parameters as discussed above; and the detector area to be irradiated after target selection is determined based on the reduced volume of interest and the X-ray tube goniometrics. Therefore, the detector area to be irradiated is different for each X-ray tube goniometric. Specifically, the detector area to be irradiated is changed at each goniometric to include the entire reduced volume of interest while excluding the surrounding breast volume outside the reduced volume of interest. In this way, at each X-ray tube goniometric, the corresponding irradiated detection area (alternatively referred to herein as the detector area to be irradiated, or the area to be irradiated) is focused to image the volume of interest including the biopsy target. By determining the detector area to be irradiated based on the reduced volume of interest and the X-ray source goniometrics, the total volume of the breast imaged after target selection is reduced. Therefore, the amount of radiation received by the patient is reduced, and the time taken to reconstruct the DBT projection image is further reduced, while achieving improved spatial resolution.

[0078] To achieve dynamic detector illumination, the collimation is adjusted at each angle, as discussed below. After target selection for DBT-guided biopsy, the detector area is changed based on the volume of interest and X-ray tube goniometrics. FIG. 3A to FIG. 3C , FIG. 4A to FIG. 4C , FIG. 5A to FIG. 5C , Figure 6 and Figure 7 Further display and description.

[0079] When the detector area to be irradiated is determined for each x-ray tube goniometer after target selection, method 200 proceeds to 214. At 214, method 200 includes acquiring a second plurality of projection images. The second plurality of projection images are DBT projection images obtained by imaging a reduced volume of the compressed breast at a plurality of angles within the angular range of the x-ray system. The second plurality of DBT projection images are obtained using dynamic detector collimation such that at each goniometer of the x-ray source, the area irradiated on the detector is changed to image the reduced volume of interest and exclude surrounding volume. Thus, acquiring the second plurality of projection images includes, at 216, adjusting the collimation at each goniometer to obtain a second narrower detector field of view based on the area to be irradiated calculated at each goniometer.

[0080] Collimation is achieved by adjusting the collimator blades at each X-ray tube goniometer. In other words, the collimator blades are adjusted at each X-ray tube goniometer based on the area to be irradiated determined at each goniometer (at 212). Thus, adjusting the collimation at each goniometer to obtain a second narrower field of view includes, at 217, adjusting one or more lateral blades and aft blades of the collimator to focus the irradiation on the volume of interest so that for each angle, the corresponding determined area to be irradiated on the detector is irradiated (by collimated X-rays) and a corresponding projection image is obtained at the detector.

[0081] For example, at a first angle measurement -α1 of the X-ray source, a first detector area A1 to be irradiated may be determined based on the reduced volume of interest and the first angle measurement -α1. The lateral blades and the rear blades of the collimator may be adjusted to provide a first dynamic collimation such that the first collimated X-ray beam passes through the reduced volume of interest and irradiates the area A1. Thus, a first projection image of the reduced volume of interest of the breast is obtained at the detector using the first dynamic collimation at the first angle measurement -α1. The X-ray source is then rotated to a second angle measurement -α2, at which the lateral blades and the rear blades of the collimator are again adjusted to provide a second dynamic collimation such that the second collimated beam irradiates the area A2 determined based on the reduced volume of interest and the second angle measurement -α2. The second projection image includes a projection of the reduced volume of interest of the breast obtained using the second dynamic collimation at the second angle measurement -α2. Similarly, if the X-ray tube can be rotated at N angles within the angular range of the X-ray system, the areas A1, A2, ..., An are determined, and corresponding projection images are obtained.

[0082] In this way, at multiple angles of the X-ray source, multiple detector areas to be irradiated are determined, and at each of the multiple angles the collimator is adjusted based on the corresponding detector area to be irradiated, and multiple projection images of a reduced volume of interest of the breast are obtained.

[0083] Next, at 220, method 200 includes reconstructing a second plurality of projection images to obtain a second three-dimensional breast image of the reduced volume of interest, the second breast image including a second plurality of DBT image slices.

[0084] After the user selects a biopsy target and before inserting the biopsy needle into the breast to the pre-firing position, a second plurality of projection images as discussed above can be obtained after anesthesia (after anesthesia is administered to the patient). The user can use the second plurality of images to confirm the target area with the biopsy target.

[0085] In one embodiment, before target selection, the X-ray system can automatically apply dynamic collimation to obtain a larger field of view, where the collimation is adjusted at each X-ray tube goniometry to illuminate a larger volume of interest, and thus image a larger volume. After target selection, the X-ray system can automatically switch to dynamic collimation to obtain a narrower detector field of view, and obtain a projection image of a reduced volume.

[0086] Continue to refer Figure 2B , method 200 includes confirming at 224 whether the biopsy needle is in a pre-fire position within the breast. Specifically, a position in which the notch of the needle is at a certain position within the tissue before reaching the lesion to be resected (i.e., target tissue) can be referred to as a pre-fire position. The pre-fire position can be determined based on input from a user via a user interface indicating that the needle is in the pre-fire position. Additionally or alternatively, the pre-fire position of the needle can be determined based on input from a biopsy tool control system (such as a Figure 1B The biopsy device controller 150 in the embodiment of the present invention is used to determine the input of the biopsy device controller 150 in the embodiment of the present invention. If the needle is not in the pre-fired position, the answer at 224 is "no", and the method 200 can continue to monitor whether the biopsy needle is in the pre-fired position.

[0087] If the needle is in the pre-fired position, the answer at 224 is "yes," and the method 200 proceeds to 226. At 226, the method 200 includes confirming whether a second, larger field of view is requested. For example, the user may desire to utilize a second, larger field of view for subsequent DBT acquisitions, and thus may indicate via the user interface that a second, larger field of view is desired. It should be understood that at any step during a DBT-guided biopsy procedure, the user may elect to adjust the detector field of view via the biopsy interface.

[0088] If a second larger field of view is requested, the answer at 226 is "yes" and method 200 proceeds to 228. At 228, method 200 includes acquiring a fourth plurality of pre-fire projection images using collimation adjusted to obtain the requested second larger field of view. In one example, dynamic collimation can be provided to obtain the requested second larger field of view. For example, based on the requested second larger field of view, a second larger volume of interest can be calculated. The second larger volume of interest can include a biopsy target volume. In addition, at each goniometer, a corresponding larger detector area to be irradiated can be calculated based on the second larger volume of interest. Furthermore, based on the larger area to be irradiated calculated for each X-ray source goniometer, the collimator can be adjusted to collimate the X-ray beam to irradiate the second larger volume of interest and subsequently irradiate the larger area on the detector. In this way, based on the second larger detector field of view requested by the user, a fourth plurality of pre-fire projection images covering the second larger breast volume can be obtained using dynamic detector collimation. Thus, in one example, acquiring a fourth plurality of pre-fire projection images to obtain a larger requested field of view may include, at 230, adjusting one or more of the rear blade position and the lateral blade position of the collimator to obtain a second larger FOV, wherein dynamic collimation is implemented at each X-ray tube angle (based on the corresponding area to be irradiated being different for each angle).

[0089] Returning to 226, if a second larger field of view is not requested, the answer at 226 is "no" and method 200 proceeds to 234. At 234, method 200 includes acquiring a third plurality of pre-fire projection images using dynamic detector collimation. This includes maintaining the second narrower detector field of view adjusted for each goniometric adjustment, as discussed above at step 214. In short, a corresponding detector area to be irradiated at each x-ray source goniometric is calculated based on the reduced volume of interest and the corresponding x-ray source goniometric. The collimator is adjusted so that the x-ray beam is adjusted to irradiate the reduced volume of interest of the breast, and after passing through the reduced volume of interest, the detector area calculated at each goniometric is irradiated. Thus, acquiring a third plurality of pre-fire projection images includes, at 236, adjusting the lateral and rear blades of the collimator at each goniometric of the x-ray source based on the reduced volume of interest and the corresponding x-ray source goniometric.

[0090] Continuing to 240, method 200 includes reconstructing the acquired pre-fire projection images to obtain a plurality of DBT pre-fire images. The plurality of DBT pre-fire images can be displayed on a user interface.

[0091] A plurality of pre-firing images can be used to confirm the position of the biopsy needle. When the biopsy needle position is confirmed (e.g., by the user), the biopsy gun can be deployed to fire the biopsy needle and collect the biopsy sample. Subsequently, a biopsy clip can be inserted at or near the biopsy site to mark the biopsy position and future monitoring.

[0092] Thus, method 200 can confirm at 242 whether the needle has fired. Additionally or alternatively, method 200 can confirm whether a biopsy clip has been inserted. Confirmation of needle firing and / or confirmation of insertion of a biopsy clip can be based on, for example, a user indication. If the answer at 242 is "no," method 200 can continue to monitor for confirmation of needle firing and / or post-firing insertion of a clip. If the answer at 242 is yes, method 200 proceeds to 244.

[0093] At 244, method 200 includes acquiring a fifth plurality of post-fire DBT projection images and / or post-clip projection images. In one example, during the acquisition of the plurality of post-fire projection images and / or post-clip projection images, the collimation may be adjusted based on the collimation applied during the acquisition of the pre-fire images. In other words, the detector area to be illuminated (i.e., the detector field of view (FOV)) may be adjusted during the post-fire acquisition in the same manner as the pre-fire acquisition. For example, if a second, larger field of view was applied during the pre-fire acquisition, the plurality of post-fire projections and / or post-clip projections may be acquired utilizing dynamic detector collimation applied to illuminate the second, larger volume of interest (e.g., as discussed at steps 228 and 230). If a second, narrower field of view is requested during the pre-fire acquisition, the plurality of post-fire projections and / or post-fire projections may be acquired utilizing dynamic detector collimation applied to illuminate the reduced volume of interest used during the pre-fire acquisition (as discussed at steps 234 and 236).

[0094] Thus, acquiring a fifth plurality of post-fire DBT projection images and / or post-clamp DBT projection images includes, at 245, adjusting the collimation based on the collimation applied during the pre-fire DBT acquisition, which includes, at 246, adjusting one or more of the lateral blade position and the rear blade position to obtain the detector FOV (larger or narrower) implemented during the pre-fire DBT acquisition. In some examples, the user may select to use the third larger field of view for post-fire acquisitions and / or post-clamp acquisitions. Thus, the controller may provide the user with the option of selecting a desired field of view (and therefore a desired volume to image) at any workflow step.

[0095] Next, at 248 , method 200 includes reconstructing the post-fire projection image and / or the post-clamp projection image to obtain a plurality of post-fire DBT images and / or post-clamp DBT images, and displaying the post-fire projection image and / or the post-clamp projection image on a user interface.

[0096] In this way, dynamic adjustment of the alignment allows for reduced radiation exposure of the patient in one or more post-target selection steps as the imaging area is reduced to a reduced volume of interest. Additionally, for one or more biopsy steps following target selection, multiple metal objects (e.g., biopsy device parts) may be present in the vicinity of the compressed breast. By limiting the imaging portion to the reduced volume of interest, imaging artifacts due to image capture of metal objects are reduced. Additionally, during a DBT-guided biopsy, the time for display of a volumetric image (i.e., the time for reconstruction) is an important factor as the user waits for the image to be displayed before proceeding to the next step. By limiting irradiation to the reduced volume of interest, the time for reconstruction following target selection is reduced.

[0097] Next, FIG. 3A to FIG. 3C An example schematic diagram of dynamic collimation adjustment during DBT acquisition after selecting a biopsy target is shown. As discussed above, dynamic collimation adjustment includes adjusting collimator blade positions, including one or more of lateral blade positions and rear blade positions, to adjust the corresponding detector area irradiated for each angle measurement of an x-ray source during DBT acquisition. When selecting a biopsy target, the controller can determine the corresponding detector area to be irradiated for each angle measurement based on a volume of interest containing the biopsy target. The controller can then determine the corresponding collimator position for each angle measurement so as to irradiate the reduced volume of interest and so that the corresponding detector area is irradiated after the collimated beam passes through the reduced volume of interest. The controller can then adjust the collimator to the corresponding collimator position at each angle measurement to output an x-ray beam having a corresponding cone angle.

[0098] Go to Figure 3A , which shows a schematic diagram of a portion 300 of an X-ray system. The illustration shows a compressed breast 320 between a compression paddle 310 and a detector 315. Specifically, the chest wall side of the detector 315 is shown. In addition, the chest wall to nipple direction is the direction of the Y axis; the lateral direction 317 is the direction of the X axis; and the direction perpendicular to the X and Y axes from the detector 315 upward to the compression paddle 310 is the direction of the Z axis.

[0099] During DBT acquisition, the X-ray source 305 can be rotated from -α to +α about a rotation center (not shown). The vertical axis 319 of the X-ray source passes through the rotation center, and when the vertical axis 319 is perpendicular to the detection surface (i.e., the XY plane), the middle position of the X-ray source 305 is called the zero degree position (indicated by α0), and the X-ray source can be rotated up to -α degrees on one side of the middle position and up to +α degrees on the other side of the middle position. Therefore, the angular range of the X-ray source is from -α degrees to +α degrees. Various side angles of the X-ray source 305 within the angular range (i.e., multiple angular positions of the X-ray source to obtain DBT acquisition) are also depicted in this illustration.

[0100] The volume of interest 322 within the compressed breast 320 is a reduced volume of interest and is determined based on the target location, breast thickness, and one or more compression paddle parameters (such as the hole area and position on the compression paddle) selected by the user. During DBT acquisition after selecting a biopsy target, the X-ray source is rotated within an angular range (between -α and +α) and the volume of interest (322) is scanned at multiple angles within the angular range to obtain multiple projection images at the detector. The collimation at the multiple angles is adjusted so that the detector area to be irradiated is based on the volume of interest. Specifically, the collimation at the multiple angles is adjusted by changing the collimation at each of the multiple angles. Therefore, for each of the multiple angles, the corresponding area irradiated on the detector is calculated based on the volume of interest and the angular position of the X-ray source. Based on the calculated area to be irradiated, the cone angle of the X-ray cone beam (depicted by the dashed line) is changed by adjusting one or more of the lateral blades and the rear blades of the collimator, thereby adjusting the collimation. For example, for each angular position of the X-ray source, including angles -α4, -α3, -α2, -α1, α0, +α1, +α2, +α3, and +α4, where α0 is the middle position of the X-ray tube, the detector area to be irradiated can be calculated as follows:

[0101] Ai=f(V,±∝j,α0)

[0102] where i = 1, 2, 3, ... n, n is the number of X-ray tube angular positions at which the reduced volume of interest (V) is scanned during DBT, ± denotes the direction of the X-ray tube starting from the middle position α0, and j = 1, 2, 3, ... ((n-1) / 2).

[0103] In addition, based on the area to be irradiated, θi can be determined, where θ is the cone angle of the X-ray beam output from the collimator, and i = 1, 2, 3, ... n. Therefore, the cone angle θi of the X-ray beam corresponds to the detector area Ai to be irradiated.

[0104] This example illustrates collimation adjustment in the lateral direction (ie, in the positive and negative directions of the X-axis). As illustrated, the collimated X-ray beam at each angle is constrained to illuminate the volume of interest 322 .

[0105] In this way, by adjusting the collimation to confine radiation to a reduced volume of interest and based on the angular position of the X-ray source, imaging artifacts outside the volume of interest can be reduced and the amount of radiation to the patient can be reduced while improving image quality and resolution.

[0106] An exemplary illustration of post-collimation for different breast thicknesses at an intermediate position of the X-ray source 305 is shown in FIG. Figure 3B and Figure 3C Specifically, Figure 3B Collimation for a smaller breast thickness 330 is shown in portion 300 of an X-ray system, and Figure 3C Collimation for a larger breast thickness 340 is shown in the portion 300 of the X-ray system. The volume of interest increases as the breast thickness increases. Thus, the volume of interest 326 ( Figure 3C ) is larger than the volume of interest 324 ( Figure 3B ). Therefore, the area to be irradiated also increases with the thickness of the breast. In order to scan a larger volume of interest, the collimation is adjusted to increase the cone angle of the collimated X-ray beam. Therefore, the cone angle θ11 ( Figure 3C ) is greater than the cone angle θ10( Figure 3B ).although Figure 3B and Figure 3C The present example in is shown for a single position of the X-ray source 305 , but it should be understood that corresponding collimation adjustments may be made for each of a plurality of angles of the X-ray source 305 .

[0107] Next, a schematic diagram of the collimation that can be applied to DBT acquisition prior to target selection is presented in Figure 3D . Specifically, a larger volume of interest is imaged before target selection. In one example, the larger volume of interest may include the entire breast in order to identify cancerous areas and locate target tissue for biopsy or a target area of ​​interest for diagnostic purposes. When the X-ray source 305 rotates within an angular range, the irradiated detector area changes at each angle and is greater than the irradiated detector area when a reduced volume is irradiated during DBT acquisition after target selection. In one example, before target selection, the cone angle at each angle can be adjusted by adjusting one or more of the lateral blades and the rear blades of the collimator so that the irradiated detector area changes to image a larger volume at each X-ray source angle. Therefore, each of the cone angles θ1, θ2, θ3 ... θ9 can be adjusted so that the X-ray beam at each angle irradiates the corresponding area on the detector after passing through the volume of interest of the breast. In one example, each of the cone angles θ1, θ2, θ3 ... θ9 can be different so that the X-ray beam at each angle irradiates a different area on the detector after passing through the volume of interest of the breast. In summary, prior to target selection, the cone angle of the X-ray beam at each angle is determined based on covering a larger volume of the compressed breast and thus a larger irradiated area on the detector in order to achieve target selection.

[0108] In another example, prior to target selection, the corresponding cone angles at multiple angles of the X-ray source may be adjusted by adjusting one or more of the lateral and posterior blades of the collimator so that the irradiated detector area is adjusted to image a larger volume at each X-ray source angle. Thus, each of the multiple cone angles of the X-ray beam may be adjusted so that the collimated X-ray beam at each angle is limited to irradiate a larger volume of interest. Thus, the corresponding irradiated area on the detector after passing through the volume of interest of the breast is adjusted based on the X-ray tube angle and the volume of interest.

[0109] Next, FIG. 4A to FIG. 4C A three-dimensional illustration of a reduced volume of interest of the breast compressed between the compression paddle 410 and the detector 415 is shown, and also different angular positions of the x-ray tube and the corresponding irradiated detection area on the detector 415 during DBT acquisition after target selection are shown. In addition, FIG. 4A to FIG. 4C A collimated X-ray field 406 (also referred to as collimated rays) and a projection of the reduced volume of interest onto the detector in the lateral direction (direction of the X-axis) are shown.

[0110] Go to Figure 4A , which shows an X-ray system (such as Figure 1A Part 400 of an X-ray system) in which the X-ray source is rotated clockwise relative to the middle position to a first angulation (when the vertical axis of the X-ray source is perpendicular to the detection surface).

[0111] The volume of interest 422 is a reduced volume of interest and is shaded gray for clarity. The volume of interest 422 is determined by the X-ray system controller based on the target location, breast thickness, and one or more compression paddle parameters (e.g., hole size and location on the paddle) selected by the user. In determining the volume of interest 422, the controller can determine the amount of opening of one or more of the lateral and rear blades of the collimator so that the collimated X-ray beam irradiates the detector area 407 (indicated by the diagonal hatching) after passing through the volume of interest 422. In this figure, the lateral collimator ray 406 is shown. In addition, it should be understood that the collimator rear blade can be adjusted to provide the desired collimation. The collimator blades 405 are adjusted so that multiple collimated rays 406 of the collimated X-ray beam pass through the volume of interest 422. Specifically, the multiple collimated rays 406 can be the outermost collimated rays 406 and pass through each corner of the cubic volume of interest 422 (each upper corner P, Q, R and S, and each lower corner L, M, N and O). Although this example shows few collimated rays 406, it should be understood that the additional outermost collimated rays and multiple additional collimated rays that pass through the volume of interest are part of the collimated X-ray beam. In addition, although this example shows a cubic volume of interest, other geometric volumes (such as a cube volume) are also within the scope of the present disclosure and can be based on the type of collimator used. In any case, the outermost collimated rays of the collimated X-ray beam can pass through each of the outermost corners of the volume of interest (including the margin volume) before irradiating the detection area of ​​the detector. Therefore, the detection area 407 irradiated by the collimated X-ray beam is based on the volume of interest 422. The detection area 407 irradiated by the collimated X-ray beam is also based on the angulation of the X-ray source and the position of the volume of interest. For example, when the minimum detector area is irradiated at the middle position, as the angulation of the X-ray source relative to the middle position increases, the detection area irradiated on the detector increases in either direction, so that the irradiation of the collimated X-ray beam is limited to the volume of interest.

[0112] Next, Figure 4B A portion 400 of an X-ray system is shown at a second angle of the X-ray source. Specifically, Figure 4B The portion 400 is shown when the X-ray source is in an intermediate position, wherein the vertical axis of the X-ray source is perpendicular to the detection surface of the detector 415. When the X-ray source is in the intermediate position, the collimator is commanded to adjust the amount of opening of the collimator so that the collimated X-ray beam illuminates the volume of interest 422. As discussed above, the collimation is adjusted so that the outermost collimated rays 406 pass through each corner of the cubic volume 422 and illuminate the detection area 427.

[0113] Figure 4CThe portion 400 of the X-ray system is shown at a third angle of the X-ray source, where the X-ray source is rotated counterclockwise so that the vertical axis of the X-ray source is at a different third angle relative to the neutral position. For each angle of the X-ray tube, the corresponding irradiated detection area can be adjusted based on the volume of interest 422 and the X-ray tube angle. For example, Figure 4A The irradiated area 407 (first angle measurement) in Figure 4B The irradiated area 427 (second angle measurement) and Figure 4C The irradiated area 457 (third measurement angle) in.

[0114] In summary, when the irradiated detection area on the detector is smallest at the minimum angulation of the X-ray source (i.e., 0 degree angulation when the X-ray source is in the middle position), for X-ray tube rotation in either direction (clockwise and counterclockwise) within the angular range of X-ray source rotation, the irradiated detection area increases as the X-ray tube angulation increases and depends on the rotation direction. In addition, for any X-ray source angulation, the outermost collimated rays can pass through the volume of interest (including the margin volume) so that each corner of the cubic volume of interest is irradiated by at least one collimated ray 406 of the collimated beam.

[0115] In this manner, only a selected portion of the compressed breast is irradiated by collimating the X-ray beam based on X-ray source angulation (e.g., angulation amount and rotation direction) and a volume of interest, where the volume of interest is based on selected target coordinates, breast thickness, and one or more compression paddle parameters. This significantly reduces imaging artifacts because the acquisition is focused on the volume of interest. Additionally, when the irradiated detection area is adjusted based on the volume of interest, the total amount of radiation received by the patient is less. Furthermore, spatial resolution is improved.

[0116] An example illustration of artifact reduction is shown in Fig. 9 Next, go to Fig. 9 , which shows an exemplary scanned image 900 of an image plane obtained during DBT acquisition without applying dynamic collimation adjustment (i.e., the irradiated detection area remains the same for all X-ray source angulations), and shows an exemplary scanned image 920 of an image plane obtained by adjusting the collimation to illuminate the detection area based on the volume of interest and the angular position. As demonstrated, when the collimation is adjusted based on the volume of interest and the angular position of the X-ray source, the imaging artifacts indicated by 910 on the scanned image 900 and 930 on the scanned image 920 are reduced.

[0117] In addition, as the breast thickness decreases, for the same angular position of the X-ray source, the area to be irradiated decreases, e.g. FIG. 5A to FIG. 5C Specifically, FIG. 5A to FIG. 5CA three-dimensional illustration of a portion 400 of an X-ray system is shown, depicting the imaging of a small breast thickness (with a diameter of 20 mm) at different angular positions of the X-ray tube during DBT acquisition after target selection. FIG. 4A to FIG. 4C 415. As the breast thickness decreases, the volume of interest decreases. Thus, for the same angulation of the x-ray source, for a smaller compressed breast thickness, the volume of interest 522 is smaller. Thus, the corresponding irradiated detection area on the detector 415 is smaller. For purposes of brevity and illustration, FIG. 5A to FIG. 5C The collimator portion is not shown, however, it should be understood that the plurality of collimated rays 506 are emitted from the collimator (such as FIG. 4A to FIG. 4C In addition, the plurality of collimated rays 506 may be the outermost collimated rays of the collimated X-ray beam.

[0118] Figure 5A A portion 400 showing an X-ray source at a first angle, Figure 5B shows a portion 400 where the X-ray source is at a second angle, and Figure 5C The portion 400 in which the X-ray source is at a third angle is shown. In addition, as discussed above, FIG. 5A to FIG. 5C The volume of interest 522 is shown for a smaller compressed breast thickness (ie, the distance between the detection surface 415 and the compression paddle 410 in the z direction is z=50 mm), while FIG. 4A to FIG. 4C The volume of interest 422 for a larger compressed breast thickness (z=100 mm) is shown for the first, second, and third angles of the X-ray source. Therefore, for the first angle, the irradiated area 507 is smaller than the irradiated area 407. Similarly, for the second angle, the irradiated area 527 is smaller than the irradiated area 427; and for the third angle, the irradiated area 557 is smaller than the irradiated area 457. Therefore, for smaller breast thicknesses (decreasing z distance), as the projection of the volume of interest on the detection surface decreases in the lateral direction (X-axis direction), the corresponding irradiated area on the detector decreases. In addition, for smaller breasts, the area irradiated in the chest wall in the direction of the nipple (Y-axis direction) is also reduced. A three-dimensional illustration of the volume of interest 522 is shown in FIG. Figure 6 , where the X-ray source is at a second angulation and the corresponding irradiated detection area 627 is in the direction from the chest wall to the nipple.

[0119] As discussed above, the collimation is adjusted so that at least one or more of the outermost collimated rays 506 pass through each corner of the cubic volume of interest 522 .

[0120] Go to Figure 6, a three-dimensional illustration depicting post-collimation for a portion 400 of an X-ray system at zero degrees of angulation of an X-ray source (i.e., a mid-position of the X-ray source) after target selection is shown. Specifically, an irradiated detection area 627 corresponding to the projection of the volume of interest 522 in the XY plane is shown for a smaller breast thickness (the distance between the detection surface 415 and the compression paddle 410 in the z direction is z=50 mm). For a smaller compressed breast thickness, the irradiated detection area 627 decreases in the chest wall to nipple direction (the Y-axis direction from the chest wall side 602 to the nipple side 604). In addition, the irradiated detection area 627 decreases relative to the irradiated detection area before target selection (at the same X-ray source angulation).

[0121] Despite Figures 2A to 6 The above embodiment described in demonstrates dynamic collimation during DBT acquisition by varying the irradiated detection area at each X-ray source angulation, but the dynamic collimation can be implemented for other mammographic modalities, including stereoscopic mammographic imaging or CESM mammographic imaging as described below.

[0122] Figure 7 A flow chart is shown that illustrates a high-level method 700 for performing dynamic collimation that may be performed during a stereotactic guided biopsy or a CESM guided biopsy using an X-ray imaging system such as Figure 1A X-ray system 10 in Figure 1B Method 700 may be performed by an image processing system such as Figure 1A The method 700 may be implemented by a controller 44 in the image processing system, an edge device connected to the image processing system, a cloud in communication with the image processing system, or any suitable combination thereof. Figure 1A Although the method 700 is described with reference to systems and components of the present invention, it should be understood that the method 700 may be implemented with other systems and components without departing from the scope of the present disclosure.

[0123] The method 700 starts at 702. At 702, the method 700 includes confirming whether the X-ray system is operating in a stereotactic guided biopsy mode or a CESM guided biopsy mode. In one example, the operating mode of the X-ray system can be determined based on an indication made by a user on a user interface of the X-ray system. For example, the controller can determine the operating mode based on the user launching an application interface corresponding to the operating mode (e.g., launching a stereotactic interface or a CESM interface). Other embodiments that utilize a vision system coupled to the X-ray system to determine the operating mode (e.g., based on accessory detection utilizing the vision system) are also within the scope of the present disclosure.

[0124] If the stereotactic guided biopsy mode or the CESM guided biopsy mode is not confirmed, the method proceeds to 703 to operate the X-ray system based on the user requested mode (e.g., quality check mode). The method 700 then ends. If the stereotactic mode or the CESM mode is confirmed, the method 700 proceeds to 705. At 705, the method 700 includes confirming whether the breast is positioned for biopsy. Step 705 is similar to Figure 2A If the breast positioning is confirmed for stereotactic biopsy or CESM biopsy, the method 700 proceeds to 706; otherwise, the method 700 may continue to monitor the breast positioning confirmation.

[0125] At 706, method 700 includes determining a volume of interest based on the breast thickness and the compression paddle parameters. In particular, the volume of interest can include a large portion of the compressed breast prior to target selection, as discussed above with respect to DBT-guided biopsy.

[0126] After determining the volume of interest, method 700 proceeds to 708. At 708, method 700 includes acquiring one or more projection images for each mammographic view. The mammographic view may be based on the mode of operation. Specifically, when operating in a CESM-guided biopsy mode, the mammographic view may include one or more of a CC view and an MLO view. It should be understood that for each view, the breast may be repositioned between acquisitions. Additionally, when operating in a CESM-guided mode, at least two projection images may be acquired. Specifically, a low energy acquisition image and a high energy acquisition image (after intravenous administration of iodinated contrast agent) may be acquired for each view.

[0127] When operating in stereotactic guided biopsy mode, at least two angled views can be obtained (e.g., at +15 degrees and -15 degrees). In addition, in stereotactic guided mode, a CC view (zero degree angulation of the X-ray source) can be obtained.

[0128] Acquiring one or more projection images for each view includes, at 710, adjusting one or more of the lateral blades and the posterior blades of the collimator to provide collimation based on a larger volume of interest prior to target selection. For each view, one or more projection images may be obtained with a collimator adjusted to illuminate a larger breast volume, and thus, a corresponding irradiated detection area on the detector is larger prior to target selection. Additionally, for a given mode, the irradiated detection area may be adjusted based on the x-ray tube position for each view. For example, when operating in a CESM-guided mode, for each of the CC views and the MLO views, the irradiated corresponding detection area may be based on the x-ray tube angle measurement at the CC view and the MLO view. When operating in a stereotactic mode, for each stereotactic view and for a CC view of zero degrees, the irradiated corresponding detection area may be adjusted based on the x-ray tube angle measurement at each view (stereotactic view angle measurement and CC view angle measurement).

[0129] Continuing to 712, for each mammographic view, a projection image may be reconstructed and displayed to the user.

[0130] For example, based on the reconstructed image, the user may select a target location via the user interface. Thus, method 700 then proceeds to 714 to determine whether the target location is selected. The target location may be within the region of interest and may be selected by the user via the X-ray system user interface and / or the biopsy tool interface based on identifying an abnormality from the reconstructed image (e.g., from step 712).

[0131] If the target is not identified, the answer at 714 is "no" and the method 700 proceeds to 715. At 715, the controller may prompt the user to identify the target and the method may return to 714 to determine if the target has been selected.

[0132] If the target is identified by the user and / or received at the controller, the answer at 714 is yes and method 700 proceeds to 716 .

[0133] At 716, method 700 includes determining a reduced volume of interest based on the target location, breast thickness, and one or more compression paddle parameters (e.g., biopsy holes on the paddle). The reduced volume of interest determined after target selection is smaller than the larger volume of interest determined before target selection.

[0134] Next, at 717, method 700 includes adjusting collimation based on the reduced volume of interest and the corresponding X-ray source goniometer for the corresponding view (e.g., zero degrees for CC views, 45 degrees for MLO views, and desired goniometer for stereotactic views). This includes adjusting one or more of the lateral leaf positions and the rear leaf positions of the collimator to illuminate the reduced volume of interest with collimated X-rays at 718. Thus, the corresponding detection area illuminated is reduced, resulting in a narrower detector field of view after target selection than the illuminated detection area before target selection for the same X-ray source goniometer.

[0135] Upon adjusting the collimator based on the reduced volume of interest and x-ray source goniometric (based on the view), method 700 proceeds to 720. At 720, method 700 includes acquiring one or more projection images per view with the collimation adjusted for the reduced volume of interest and narrower detector field of view.

[0136] Continuing to 722, method 700 includes reconstructing one or more projection images for each view and displaying the reconstructed images to a user on a user interface.

[0137] Method 700 then ends.

[0138] In this manner, in response to selecting a target, the collimator leaf positions are commanded to provide collimated X-rays for a reduced volume of interest. Additionally, as discussed above with respect to DBT-guided biopsy, the reduced volume of interest can be based on breast thickness. For example, the reduced volume of interest is larger for greater compressed breast thickness and decreases as the compressed breast thickness decreases.

[0139] It should be understood that the collimation adjustment can be implemented for one or more imaging procedures performed with the X-ray mammography system. In addition to the above-mentioned image-guided interventional procedures, the imaging procedures can also include one or more of diagnostic imaging procedures and screening imaging procedures. For example, during one or more of the diagnostic procedures and the screening procedures, the user can select a region of interest, and a reduced volume based on the region of interest can be determined by the controller. The collimator can then be adjusted to irradiate the reduced volume including the region of interest. One or more of the diagnostic imaging procedures and the screening imaging procedures can include a 2D screening procedure, a 2D diagnostic procedure, a DBT screening procedure, a DBT diagnostic procedure, and a CESM diagnostic procedure.

[0140] Exemplary collimation adjustments based on a reduced volume of interest for stereotactic-guided biopsy mode and CESM-guided biopsy mode are described below with respect to Fig. 8A , Figure 8B and Figure 8C exhibit.

[0141] Go to Fig. 8A , Figure 8B and Figure 8C , each of which shows an X-ray system (such as Figure 1A 800 of an X-ray system). Specifically, the X-ray source 805 is shown at an intermediate angle (zero angle), where the vertical axis 819 of the X-ray source is perpendicular to the detection surface of the detector 915. Fig. 8A , shows the collimation of the x-ray beam in the lateral direction 817 (i.e., the x-axis direction), as indicated by the dashed line. When a biopsy target is selected, the collimation is adjusted to irradiate a reduced volume of interest 802 of the breast 820 compressed between the compression paddle 810 and the detector 815. Specifically, the collimation is adjusted so that the irradiation of the collimated x-ray beam is limited to the reduced volume, and therefore, the irradiated detection area on the detection surface is reduced after the target is selected. In addition, the irradiated detection area on the detection surface is based on the x-ray source angle measurement. For example, as the x-ray source angle measurement increases, the corresponding detection area irradiated by the collimated beam after passing through the reduced volume of interest also increases. As discussed above, the reduced volume of interest 802 is determined based on the selected biopsy target coordinates, the compressed breast thickness, and one or more compression paddle parameters.

[0142] In addition, exemplary illustrations of the back collimation (in the Y-axis direction from the chest wall to the nipple) for different breast thicknesses at the middle position of the X-ray source 805 are shown in FIG. Figure 8B and Figure 8C Specifically, Figure 8B Collimation for a smaller breast thickness 830 is shown, and Figure 8C Collimation for a larger breast thickness 840 is shown. The volume of interest increases as the breast thickness increases. Thus, the volume of interest 852 ( Figure 8C ) is larger than the volume of interest 802 ( Figure 8B ). Therefore, the area to be irradiated also increases with the thickness of the breast. In order to scan a larger volume of interest, the collimation is adjusted to increase the cone angle of the collimated X-ray beam. Therefore, the cone angle θ14 ( Figure 8C ) is greater than the cone angle θ13( Figure 8B ).although Figure 8B and Figure 8C The present example in is shown for a single position of the X-ray source 805 , but it should be understood that corresponding collimation adjustments may be made for each of the desired angles of the X-ray source 805 .

[0143] A technical effect of adjusting the irradiated detection area based on the volume of interest during acquisition after target selection is a reduction in imaging artifacts. Another technical effect of dynamically changing the irradiated detection area during acquisition after target selection is a reduction in reconstruction time. Yet another technical effect of dynamically changing the detection area after target selection is an improvement in the spatial resolution of the volume of interest.

[0144] An embodiment of an X-ray system includes: during an imaging procedure performed with the X-ray system, adjusting collimation based on a workflow step of the imaging procedure to image a corresponding volume of interest. A first example of the method includes, wherein adjusting collimation includes irradiating a first larger area on a detector of the X-ray system based on the first volume of interest during a first positioning acquisition before selecting a target region of interest. In a second example of the method, the second example optionally includes the first example, the method also includes, wherein adjusting collimation includes irradiating a second smaller area on the detector based on the second volume of interest in response to selecting the target region of interest; and wherein the first volume of interest is larger than the second volume of interest. In a third example of the method, the third example optionally includes one or both of the first example and the second example, the method also includes, wherein the first larger area and the second smaller area are also based on an angular position of an X-ray source of the X-ray system. In a fourth example of the method, the fourth example optionally includes one or more examples of each of the first to third examples, the method also includes, wherein the second volume of interest is determined based on the selected region of interest, the thickness of the compressed breast, and one or more compression paddle parameters. In a fifth example of the method, the fifth example optionally includes one or more examples of each of the first to fourth examples, the method further includes, wherein the one or more compression paddle parameters include the size and position of the compression paddle hole. In a sixth example of the method, the sixth example optionally includes one or more examples of each of the first to fifth examples, the method includes, during digital breast tomosynthesis (DBT) acquisition, for each angular position of the X-ray source, in response to selecting a target region of interest, adjusting collimation based on a second volume of interest and a corresponding angular position of the X-ray source. In a seventh example of the method, the seventh example optionally includes one or more examples of each of the first to sixth examples, the method includes, wherein adjusting collimation based on the second volume of interest and the corresponding angular position of the X-ray source includes adjusting one or more collimator blade positions at each angular position of the X-ray source. In an eighth example of the method, the eighth example optionally includes one or more examples of each of the first to seventh examples, the method includes, wherein adjusting collimation based on the second volume of interest and the corresponding angular position of the X-ray source includes changing the area to be irradiated at each angular position of the X-ray source. In a ninth example of the method, which optionally includes one or more examples of each of the first to eighth examples, the method includes adjusting collimation based on a first volume of interest and a corresponding angular position of an X-ray source before selecting a target region of interest during DBT acquisition.

[0145] An embodiment of a method for an X-ray system includes: during an image-guided interventional procedure, prior to selecting a target, performing a first tomosynthesis scan of a compressed breast using a first collimation at a plurality of angular positions of an X-ray source of the X-ray system; reconstructing a first set of images from the first tomosynthesis scan data; in response to the target selection from the first set of images, performing a second tomosynthesis scan of the compressed breast using a second collimation at a plurality of angular positions of the X-ray system; and reconstructing a second set of images from the first tomosynthesis scan data; wherein the first collimation is based on a larger volume of interest; and wherein the second collimation is based on a reduced volume of interest. A first example of the method includes, wherein the first collimation is based on a corresponding X-ray source angle measurement and is adjusted to illuminate a corresponding larger area on a detector of the X-ray system at each of the plurality of angular positions; wherein the second collimation is based on a corresponding X-ray source angle measurement and is adjusted to illuminate a corresponding reduced area on the detector at each of the plurality of angular positions. In a second example of the method, the second example optionally includes the first example, and further includes, wherein each of the larger area and the reduced area is changed at each angular position by adjusting one or more of the lateral blade position and the rear blade position of the collimator at each angular position; and wherein the first average detector area irradiated during the first tomosynthesis scan is greater than the second average detector area irradiated during the second tomosynthesis scan. In a third example of the method, the third example optionally includes one or both of the first example and the second example, the method further includes, when the interventional tool is in the pre-fire position, performing a pre-fire tomosynthesis scan of the compressed breast using the second collimation with the interventional tool in the pre-fire position; and reconstructing a pre-fire image based on the pre-fire scan data from the pre-fire tomosynthesis scan. In a fourth example of the method, the fourth example optionally includes one or more of each of the first to third examples, the method further includes, wherein the reduced volume of interest is based on the position of the selected target, the compressed breast size, and one or more compression paddle parameters. In a fifth example of the method, the fifth example optionally includes one or more examples of each of the first to fourth examples, the method further includes, wherein the image-guided interventional procedure is an image-guided biopsy procedure. In a sixth example of the method, the sixth example optionally includes one or more examples of each of the first to fifth examples, the method includes, wherein the volume of interest increases as the thickness of the compressed breast increases; and wherein the compression paddle parameters include compression paddle hole size and position.

[0146] An embodiment of an imaging system is provided. The imaging system includes: a radiation source that rotates within an angular range around an axis of the imaging system; a collimator that is used to adjust radiation emission from the radiation source; a detector that is used to receive radiation rays from the radiation source via the collimator and generate multiple projection images of a sample positioned between the radiation source and the detector; a compression paddle that is used to position the sample between the compression paddle and the detector; a biopsy device that includes a biopsy tool and a biopsy needle mounted on the biopsy tool, the biopsy device is coupled to the imaging system and positioned between the radiation source and the detector; and a processor that has executable instructions stored in a non-volatile memory for: adjusting one or more collimator leaves based on the entire volume of the sample before receiving biopsy target coordinates The invention relates to an imaging system for imaging a patient with a certain area to be irradiated on a detector, and performing a first tomosynthesis scan by adjusting one or more collimator blade positions at each angular position of a radiation source; reconstructing a first set of images from the first tomosynthesis scan; displaying the first set of images on a user interface of the imaging system; determining a reduced volume of interest based on the biopsy target coordinates, the compressed breast thickness, and one or more compression paddle parameters in response to receiving biopsy target coordinates; determining a corresponding area to be irradiated on the detector based on the reduced volume of interest for each radiation source angular position; performing a second tomosynthesis scan by adjusting one or more collimator blades at each radiation source angular position based on the corresponding area to be irradiated; reconstructing a second set of images from the first tomosynthesis scan; and displaying the second set of images on the user interface. In the first example of the imaging system, the corresponding area to be irradiated increases as the angulation of the radiation source increases relative to an intermediate position, at which the vertical axis of the radiation source is perpendicular to a detection surface of the detector. In a second example of the imaging system, the second example optionally includes the first example, and adjusting the one or more collimator blades includes adjusting one or more of a lateral blade position and a posterior blade position.

[0147] When introducing the elements of various embodiments of the present disclosure, the words "one", "a kind of" and "the" are intended to mean that there are one or more elements in these elements. The terms "first", "second", etc. do not represent any order, amount or importance, but are used to distinguish one element from another element. The terms "comprise", "include" and "have" are intended to be inclusive, and mean that additional elements may also exist in addition to the listed elements. As used herein, the terms "connected to", "connected to", etc., an object (e.g., material, element, structure, member, etc.) can be connected to or connected to another object, regardless of whether the one object is directly connected or connected to another object, or whether there are one or more intervening objects between the one object and another object. In addition, it should be understood that reference to "one embodiment" or "embodiment" of the present disclosure is not intended to be interpreted as excluding the existence of additional embodiments that also include the cited features.

[0148] In addition to any previously indicated modifications, numerous other variations and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present description, and the appended claims are intended to cover such modifications and arrangements. Therefore, although the information has been described above in detail in conjunction with what are currently considered to be the most practical and preferred aspects, it will be apparent to those of ordinary skill in the art that many modifications may be made, including but not limited to form, function, mode of operation, and use, without departing from the principles and concepts set forth herein. Likewise, as used herein, the examples and embodiments are intended to be illustrative in all respects only and should not be construed as limiting in any way.

Claims

1. A method for an X-ray system, comprising: adjusting collimation based on the angular position of the X-ray source and a corresponding reduced volume of interest at each of the plurality of angular positions to reduce radiation during the imaging procedure and to image the corresponding reduced volume of interest based on a workflow step of the imaging procedure during an imaging procedure performed with the X-ray source of the X-ray system in which the X-ray source passes through a plurality of angular positions, wherein adjusting the collimation comprises changing both a cone angle and a detector area of ​​an X-ray beam output by the X-ray source at each of the plurality of angular positions based on the reduced volume of interest, and wherein the reduced volume of interest is determined based on estimated coordinates of the selected target, imaging the entire corresponding reduced volume of interest while excluding volume outside the corresponding reduced volume of interest, wherein the reduced volume of interest is a cubic volume of interest, and wherein adjusting the collimation comprises adjusting the collimator such that at each of the plurality of angular positions, outermost collimated rays pass through each corner of the cubic volume of interest before illuminating the detector area.

2. A method according to claim 1, wherein adjusting the collimation includes irradiating a first area on a detector of the X-ray system based on a first volume of interest during a first positioning acquisition before selecting the selected target, and wherein irradiating the first area includes adjusting the cone angle at each of an initial plurality of angular positions so that the corresponding X-ray beam at each of the initial plurality of angular positions is confined to the first volume of interest.

3. The method of claim 2 , wherein the corresponding reduced volume of interest comprises a second volume of interest, wherein the first volume of interest is larger than the second volume of interest, and wherein the collimation limits radiation to the reduced volume of interest based on the angular position of the X-ray source and the corresponding reduced volume of interest at each of the plurality of angular positions.

4. The method of claim 1 , wherein adjusting collimation based on the corresponding reduced volume of interest and the angular position of the X-ray source comprises adjusting one or more of a lateral collimator blade position and a rearward collimator blade position of the collimator blades at each of a plurality of angular positions of the X-ray source to adjust the cone angle of the X-ray beam output.

5. The method of claim 1, wherein the selected target is a user-selected target made from a first volume of interest already imaged via the X-ray system, and wherein the first volume of interest is larger than the reduced volume of interest.

6. A method for an X-ray system, comprising: During image-guided interventional procedures, performing a first tomosynthesis scan of the compressed breast using a first collimation at a plurality of angular positions of an X-ray source of the X-ray system before selecting a target; reconstructing a first set of images from data of the first tomosynthesis scan; performing a second tomosynthesis scan of the compressed breast with a second collimation at the plurality of angular positions of the X-ray system in response to a target selection from the first set of images; as well as reconstructing a second set of images from data from the second tomosynthesis scan; wherein the first collimation is based on a larger volume of interest; wherein the second collimation is based on a reduced volume of interest, and wherein the reduced volume of interest is smaller than the larger volume of interest; wherein the second tomosynthesis scanning includes adjusting the second collimation based on an angular position of the x-ray source and the reduced volume of interest at each of the plurality of angular positions to reduce radiation during the image-guided interventional procedure; and wherein adjusting the second collimation comprises changing both a cone angle and a detector area of ​​an X-ray beam output by the X-ray source at each of the plurality of angular positions based on the reduced volume of interest, and wherein the reduced volume of interest is determined based on estimated coordinates of the selected target, and imaging the entire reduced volume of interest while excluding volume outside the reduced volume of interest, wherein the reduced volume of interest is a cubic volume of interest, and wherein adjusting the second collimation comprises adjusting the collimator such that at each of the plurality of angular positions, outermost collimated rays pass through each corner of the cubic volume of interest before illuminating the detector area.

7. A method according to claim 6, wherein the first collimation is also based on the corresponding X-ray source angle measurement, and the first collimation is adjusted to illuminate a corresponding larger area on the detector of the X-ray system at each of the multiple angular positions, and wherein the second collimation is also based on the corresponding X-ray source angle measurement, and the second collimation is adjusted to illuminate a corresponding reduced area on the detector at each of the multiple angular positions.

8. The method according to claim 6, further comprising: When the interventional tool is in the pre-fired position, performing a pre-fire tomosynthesis scan of the compressed breast using the second collimation with the interventional tool in the pre-fire position; and A pre-fire image is reconstructed based on the pre-fire scan data from the pre-fire tomosynthesis scan.

9. The method of claim 6, wherein the reduced volume of interest is based on the estimated coordinates of the selected target, a compressed breast size, and one or more compression paddle parameters.

10. The method of claim 9, wherein the reduced volume of interest increases in volume as the compressed breast thickness increases, wherein a corresponding cone angle for illuminating the reduced volume of interest increases as the compressed breast thickness increases via the adjusted second collimation, and wherein the one or more compression paddle parameters include compression paddle hole size and position.

11. An imaging system comprising: a radiation source that rotates within an angular range about an axis of the imaging system; a collimator for adjusting radiation emission from the radiation source; a detector for receiving radiation rays from the radiation source via the collimator and generating a plurality of projection images of a sample positioned between the radiation source and the detector; a compression paddle for positioning the sample between the compression paddle and the detector; a biopsy device, the biopsy device comprising a biopsy tool and a biopsy needle mounted on the biopsy tool, the biopsy device coupled to the imaging system and positioned between the radiation source and the detector; and A processor having executable instructions stored in a non-transitory memory for: During the imaging procedure, before receiving the biopsy target coordinates, adjusting collimation by adjusting one or more collimator blades to illuminate an area on the detector based on an entire volume of the sample, and performing a first tomosynthesis scan by adjusting the one or more collimator blades at each of a plurality of angular positions of the radiation source; reconstructing a first set of images from the first tomosynthesis scan; displaying the first set of images on a user interface of the imaging system; In response to receiving the biopsy target coordinates, determining a reduced volume of interest based on the biopsy target coordinates, a compressed breast thickness, and one or more compression paddle parameters; determining a corresponding area to be illuminated on the detector based on the reduced volume of interest for each of the plurality of angular positions of the radiation source; performing a second tomosynthesis scan by adjusting the one or more collimator blades at each of the plurality of angular positions of the radiation source based on a corresponding area to be irradiated, wherein the adjustment of the one or more collimator blades is further based on the reduced volume of interest at each of the plurality of angular positions of the radiation source to reduce radiation during the imaging procedure, and wherein adjusting the one or more collimator blades comprises changing a cone angle of an x-ray beam irradiated by radiation output by the radiation source and a detector area irradiated by radiation output by the radiation source at each of the plurality of angular positions based on the reduced volume of interest, and wherein the reduced volume of interest is based on the received biopsy target coordinates, and imaging the entire reduced volume of interest while excluding volume outside the reduced volume of interest; reconstructing a second set of images from the second tomosynthesis scan; and displaying the second set of images on the user interface, wherein the reduced volume of interest is a cubic volume of interest, and wherein adjusting the collimation comprises adjusting the collimator such that at each of the plurality of angular positions, outermost collimated rays pass through each corner of the cubic volume of interest before illuminating the detector area.

12. The system of claim 11, wherein the corresponding area to be irradiated increases as the angulation of the radiation source increases relative to an intermediate position where a vertical axis of the radiation source is perpendicular to a detection surface of the detector.

Images