Systems and methods for LiDAR guided patient positioning devices for computed tomography systems

Abstract

The invention relates to a system and method for a LiDAR guided patient positioning device for a computed tomography system. In one embodiment, a method includes receiving data acquired with a light detection and ranging (LiDAR) scanning system physically coupled to a computed tomography (CT) imaging system of a subject to be imaged disposed on a gantry of a table configured to move the subject into and out of an aperture of a gantry of the CT imaging system. The method further includes generating a multi-dimensional imagery of the subject that characterizes the topographic features of the subject. The method further includes causing a multi-dimensional imagery that is positioned on the stand and characterizes the current position of the subject to be displayed on a display, where the display is disposed adjacent the table within the field of view of the subject. The method even further includes providing instructions on the display to enable the subject to guide itself to a target location on the stent for a CT scan with the CT imaging system.

Description

Background Art

[0001] The subject matter disclosed herein relates to medical imaging systems, and more particularly, to light detection and ranging or laser imaging, detection and ranging (LiDAR) guided patient positioning apparatus for computed tomography (CT) imaging systems.

[0002] In CT, X-ray radiation is passed across a subject of interest (such as a human patient), and a portion of the radiation strikes a detector that collects image data. In a digital X-ray system, a photodetector produces a signal representing the amount or intensity of radiation striking a discrete pixel area of ​​the detector surface. The signal can then be processed to generate an image that can be displayed for viewing. In the images produced by such a system, it is possible to identify and examine internal structures and organs inside the patient's body. In a CT system, as the gantry moves around the patient, the detector array (comprising a series of detector elements or sensors) produces similar signals through various positions, allowing a volume reconstruction to be obtained.

[0003] In some cases, the patient to be imaged may have a highly infectious disease. It would be practical for a technician who does not enter the scanning room to assist in positioning the patient for a CT scan to avoid exposing the technician to infection. Therefore, a method is needed that enables the correct positioning of the patient for a CT scan without exposing the technician to a highly infectious disease. Summary of the invention

[0004] The following summarizes certain embodiments commensurate with the scope of the originally claimed subject matter. These embodiments are not intended to limit the scope of the claimed subject matter, but rather, these embodiments are intended only to provide a brief overview of possible forms of the subject matter. In fact, the subject matter may include a variety of forms that may be similar to or different from the embodiments described below.

[0005] In one embodiment, a medical imaging system is provided. The medical imaging system includes a CT imaging system. The CT imaging system includes a gantry having an aperture that can rotate about an axis of rotation. The CT imaging system also includes: a table configured to move a subject to be imaged into and out of the aperture of the gantry; a radiation source mounted on the gantry and configured to emit an X-ray beam; and a detector configured to detect the X-ray beam emitted by the radiation source. The medical imaging system also includes a display that is disposed adjacent to the table within the subject's field of view. The medical imaging system also includes a LiDAR scanning system that is physically coupled to the CT imaging system. The LiDAR scanning system is configured to acquire data of the subject from different angular positions relative to the axis of rotation. The medical imaging system also includes a processing circuit system configured to receive data acquired by the LiDAR scanning system to generate a multidimensional virtual image of the subject representing the subject's morphological features, to display a multidimensional virtual image representing the subject's current position positioned on a support on a display, and to provide instructions on the display so that the subject can guide himself to a target position on the support so as to perform a CT scan using the CT imaging system.

[0006] In another embodiment, a computer-implemented method is provided. The computer-implemented method includes receiving data acquired by a light detection and ranging (LiDAR) scanning system at a processor, the LiDAR scanning system being physically coupled to a computed tomography (CT) imaging system of a subject to be imaged disposed on a support of a table, wherein the table is configured to move the subject into and out of an orifice of a rack of the CT imaging system. The computer-implemented method also includes generating, by the processor, a multidimensional virtual image of the subject representing the morphological features of the subject. The computer-implemented method also includes causing, by the processor, the multidimensional virtual image representing the current position of the subject positioned on the support to be displayed on a display, wherein the display is disposed adjacent to the table within the subject's field of view. The computer-implemented method even includes providing, by the processor, instructions on the display to enable the subject to guide itself to a target position on the support for CT scanning with the CT imaging system.

[0007] In another embodiment, a non-transitory computer readable medium includes processor executable code, which when executed by a processor causes the processor to perform an action. The action includes receiving data acquired by a light detection and ranging or laser imaging, detection and ranging (LiDAR) scanning system, which is physically coupled to a computed tomography (CT) imaging system of a subject to be imaged on a support of a workbench, wherein the workbench is configured to move the subject into and out of the orifice of the rack of the CT imaging system. The action also includes generating a multidimensional virtual image of the subject representing the morphological features of the subject. The action also includes causing a multidimensional virtual image representing the current position of the subject positioned on the support to be displayed on a display, wherein the display is arranged to be adjacent to the workbench within the subject's field of view. The action even includes providing instructions on the display so that the subject can guide himself to a target position on the support so as to perform a CT scan with the CT imaging system. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] These and other features, aspects, and advantages of the disclosed subject matter will be better understood when the following detailed description is read with reference to the accompanying drawings, in which like characters refer to like parts throughout the several views, and in which:

[0009] Figure 1 is a graphical representation of a CT imaging system according to aspects of the present disclosure;

[0010] Figure 2 According to various aspects of the present disclosure Figure 1 Block diagram of the CT imaging system in;

[0011] Figure 3 is a flow chart of a method for acquiring and utilizing LiDAR data for positioning according to aspects of the present disclosure;

[0012] Figure 4 is a flow chart of a method for acquiring and utilizing LiDAR for patient positioning (eg, using an external display) in accordance with aspects of the present disclosure;

[0013] Figure 5 According to various aspects of the present disclosure Figure 1 A schematic diagram of a CT imaging system in which the CT imaging system is coupled to an external display for providing patient positioning guidance;

[0014] Figure 6 According to various aspects of the present disclosure Figure 6 A schematic diagram of a CT imaging system in which a current position and a target position of a patient are displayed on an external display;

[0015] Figure 7 is a schematic diagram of a screen on an external display of a CT imaging system providing positioning guidance (wherein a patient is in a first incorrect position) according to aspects of the present disclosure;

[0016] Figure 8 is a schematic diagram of a screen on an external display of a CT imaging system providing positioning guidance (wherein the patient is in a second incorrect position) according to aspects of the present disclosure;

[0017] Fig. 9 According to various aspects of the present disclosure Figure 6 A schematic diagram of a CT imaging system showing a current position and a target position of a patient (wherein the patient is in a correct position);

[0018] Fig.10 is a flow chart of a method for centering a target for scanning according to aspects of the present disclosure;

[0019] Fig.11 is a schematic diagram illustrating visualization of acquired 3D LiDAR data and characterization of segmented 3D LiDAR data of a patient according to aspects of the present disclosure;

[0020] Fig.12 is a schematic diagram of components for determining a center of a region of interest of a patient according to aspects of the present disclosure;

[0021] Fig.13 is a schematic diagram illustrating isocenter positioning offset calculation utilizing an automatic table height adjustment function for a patient undergoing a CT scan (eg, a diagnostic scan) in accordance with aspects of the present disclosure;

[0022] Fig.14 is a schematic diagram showing isocenter offset calculation using automatic table height adjustment for a phantom used to perform a CT calibration scan; and

[0023] Fig.15 is a schematic diagram of components for determining a mass attenuation center of a region of interest of a patient in accordance with aspects of the present disclosure. DETAILED DESCRIPTION

[0024] One or more specific embodiments will be described below. In order to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be understood that in the development of any such actual implementation, as in any engineering or design project, many implementation-specific decisions must be made to achieve the developer's specific goals, such as complying with system-related and business-related constraints that may vary from implementation to implementation. In addition, it should be understood that such development efforts may be complex and time-consuming, but are still routine tasks for design, fabrication, and manufacturing for ordinary technicians who benefit from this disclosure.

[0025] When introducing elements of various embodiments of the present subject matter, the articles "a," "an," "the," and "said" are intended to indicate that there are one or more elements. The terms "comprising," "including," and "having" are intended to be inclusive, and mean that there may be additional elements in addition to the listed elements. Furthermore, any numerical examples in the following discussion are intended to be non-limiting, and thus the additional numerical values, ranges, and percentages are within the scope of the disclosed embodiments.

[0026] Although the various aspects discussed below may be provided in the context of medical imaging, it should be understood that the present technology is not limited to such medical contexts. In fact, providing examples and explanations in such medical contexts is only to facilitate explanation by providing examples of realistic specific implementation and application. However, the present method may also be used in other contexts, such as for tomographic image reconstruction of industrial computed tomography (CT) used in non-destructive inspection (i.e., quality control or quality audit applications) of manufactured parts or manufactured products and / or non-invasive inspection (i.e., security inspection or screening applications) of packages, boxes, luggage, etc. In general, the present method can be used to provide accurate 3D information of a target in any imaging or screening context to improve workflow processes and post-processing steps.

[0027] The present disclosure provides systems and methods for combining LiDAR-based technology with CT imaging systems to more effectively assist various workflows. LiDAR systems are remote sensing methods for measuring target objects at variable distances from a source. With the advancement of LiDAR technology, it can now produce 3D renderings of subjects with high spatial resolution (e.g., sub-millimeter (mm) accuracy). The disclosed technology does not require any X-ray radiation to image the target or patient, and only requires the time-of-flight information of the reflected pulsed light (e.g., laser) to calculate and reproduce the patient's 3D information (e.g., depth-related information). Multiple views are used to cover the entire target area to reproduce high-fidelity 3D information. In certain embodiments, a light image can be acquired by moving a data acquisition system (i.e., a LiDAR scanning system with one or more LiDAR scanners or instruments) across the target (e.g., along the rack). In this embodiment, the data acquisition system can be integrated outside the scanning window (and therefore physically coupled to the CT system) and rotated to capture multiple views. In certain embodiments, multiple LiDAR scanners or instruments can be placed around the patient across different angular positions to capture the entire region of interest.

[0028] LiDAR-based data may be acquired before a CT scan is performed on a target or patient. LiDAR-based data may be utilized as part of a patient positioning device for performing a CT scan. Specifically, the processing circuit system may be configured to receive data acquired using a LiDAR scanning system to generate a multi-dimensional (e.g., two-dimensional (2D) or three-dimensional (3D)) virtual image of a subject (e.g., a patient) that characterizes the morphological features of the subject, so that a virtual image that characterizes the current position of the subject positioned on a support is displayed on a display (e.g., an external display coupled to a housing of a rack, a ceiling in a scanning room, etc.), and instructions are provided on the display so that the subject can guide himself to a target position on the support so that a CT scan is performed using a CT imaging system. In certain embodiments, the processing circuit system is configured to provide instructions to display a multi-dimensional virtual image (e.g., an image) positioned on a support at a target position together with a multi-dimensional virtual image positioned on a support at a current position on a display. In certain embodiments, instructions may be provided by automatic voice commands, visible light, or tactile prompts. In certain embodiments, the processing circuit system is also configured to template match the current position of the subject with the target position. In certain embodiments, the processing circuit system is also configured to provide a user-perceivable indication of whether the current position of the subject matches the target position. In certain embodiments, a user-perceivable indication is provided by color coding a shape on a display (e.g., a straight line shape such as a box), which is arranged to surround a virtual image in the current position positioned on a support. For example, when the current position of the subject matches the target position, the shape can be displayed as a first color. When the current position of the subject does not match the target position, the shape can also be displayed as a second color (different from the first color). In certain embodiments, the user-perceivable indication is a pointing arrow shown on the display to assist the subject in reaching the target position. In certain embodiments, the processing circuit system is configured to provide additional instructions to the subject to keep the current position of the CT scan when the current position of the subject does not match the target position. In certain embodiments, the processing circuit system is configured to determine the target position based on the scanning protocol for CT scanning. It should be noted that the information provided by the LiDAR-based data can be utilized in other workflows (eg, automatically adjusting the table height based on the isocenter offset used to scan a patient or calibration phantom).

[0029] The LiDAR-guided patient positioning device guides and assists the subject in positioning himself. Specifically, the LiDAR-based data is used to guide the subject within the interactive virtual vision device to improve the overall efficiency and robustness of the workflow using the CT scanner. The LiDAR-based data generates high-fidelity positional 3D data without projecting any markers or patterns on the subject. Therefore, data can be easily collected, and the 3D point cloud information can be effectively used to improve the robustness of the CT data acquisition workflow process. This also enables technicians to leave the scanning room during patient positioning, thereby reducing the potential spread of any infectious diseases that the subject may have. The automatic workbench adjustment function also ensures that portion optimization and automatic phantom adjustment are achieved during calibration. The disclosed embodiments achieve easy and efficient workflow and / or portion optimization.

[0030] Taking into account the foregoing and referring to Figure 1 and Figure 2 , a CT imaging system 10 is shown by way of example. The CT imaging system 10 includes a gantry 12 coupled to a housing 13 (e.g., a gantry housing). The gantry 12 has a rotating component and a fixed component. The gantry 12 has an X-ray source 14 that projects a beam of X-rays 16 toward an X-ray detector assembly or an X-ray detector array 15 (e.g., having a plurality of detector modules) on the opposite side of the gantry 12. The X-ray source 14 and the X-ray detector assembly 15 are disposed on the rotating portion of the gantry 12. The X-ray detector assembly 15 is coupled to a data acquisition system (DAS) 33. The plurality of detector modules of the X-ray detector assembly 15 detect the projected X-rays that pass through a patient or subject 22 (disposed on a support 23 of a table 36), and the DAS 33 converts the data into digital signals for subsequent processing. Each detector module of the X-ray detector assembly 15 in a conventional system generates an analog electrical signal that represents the intensity of the incident X-ray beam and, therefore, the intensity of the beam that is attenuated when the incident X-ray beam passes through the patient 22. During a scan to acquire x-ray projection data, the gantry 12 and components mounted thereon are rotated about a center of rotation 24 (eg, isocenter) to collect attenuation data from multiple viewing angles relative to the imaging volume.

[0031] The rotation of the gantry 12 and the operation of the x-ray source 14 are controlled by a control mechanism 26 of the CT system 10. The control mechanism 26 includes an x-ray controller 28, which provides power and timing signals to the x-ray source 14, and a gantry motor controller 30, which controls the rotational speed and position of the gantry 12.

[0032] The imaging system 10 also includes a light detection and ranging (LiDAR) scanning system 32 physically coupled to the imaging system 10. The LiDAR scanning system 32 includes one or more LiDAR scanners or instruments 34. As depicted, the LiDAR scanning system 32 has one LiDAR scanner 34. One or more LiDAR scanners 34 are utilized to acquire depth-related information (LiDAR data or light images) of the patient 22 with high spatial fidelity. The depth-related information is utilized during a subsequent workflow for a CT scan. The one or more LiDAR scanners 34 emit pulsed light 35 (e.g., laser) at the patient 22 and detect the pulsed light reflected from the patient 22. The LiDAR scanning system 32 is configured to acquire LiDAR data from a plurality of different views (e.g., at different angular positions relative to the axis of rotation 24).

[0033] In certain embodiments, such as Figure 1 and Figure 2 , a LiDAR scanner 34 is coupled to the gantry 12. Specifically, the LiDAR scanner 34 is disposed outside a scanning window within the gantry housing 13. The LiDAR scanner 34 rotates across the patient 22 to acquire LiDAR data at different angular positions. In certain embodiments, multiple LiDAR scanners 34 may be coupled to the gantry 12 and rotated to acquire LiDAR data at different angular positions.

[0034] In certain embodiments, multiple LiDAR scanners 34 may be coupled to the gantry 12 in fixed positions but disposed at different angular positions (eg, relative to the axis of rotation 24). A LiDAR scanner 34 in a fixed position may acquire LiDAR data while remaining stationary.

[0035] In some embodiments, the LiDAR scanning system 32 can be external to the gantry 12, but still physically coupled to the imaging system 10. For example, multiple LiDAR scanners 34 can be coupled to a LiDAR panel (e.g., at different angular positions relative to the axis of rotation 24), which is coupled to a rail system. The rail system can be coupled to the gantry housing 13 or the table 36 of the system 10. The rail system can be configured to move the LiDAR panel toward and away from the gantry 12. In some embodiments, the rail system can also be configured to rotate the LiDAR panel about the axis of rotation 24.

[0036] The LiDAR scanning system 32 includes a LiDAR controller 38, which is configured to provide timing and control signals to one or more LiDAR scanners 34 for acquiring LiDAR data at different angular positions. LiDAR data can be acquired before, during and / or after the CT scan of the patient 22. The LiDAR scanning system 32 also includes a LiDAR data processing unit 40 that receives or obtains LiDAR data from one or more LiDAR scanners 34. The LiDAR data processing unit 40 utilizes the flight information time of the reflected pulsed light and processes the LiDAR data (e.g., obtained in different views) to generate accurate 3D measurements of the patient 22. The 3D measurements of the patient 22 have high spatial resolution (e.g., sub-millimeter accuracy). As described above, the 3D measurements can be utilized during the subsequent workflow of the CT scan, as described in more detail below. A display 41 (e.g., an external display) is coupled to the LiDAR data processor unit 40. The display 41 is arranged adjacent to the workbench 36 within the field of view of the patient 22. In some embodiments, the display 41 is coupled to the gantry housing 13. In some embodiments, the display 41 is coupled to the ceiling or other location in the scanning room. In some embodiments, the display 41 includes a speaker 43 for providing automatic voice instructions to help the patient 22 guide himself. In some embodiments, the speaker 43 can be separated from the display and disposed at another location in the scanning room.

[0037] 3D measurement information from the LiDAR scanning system 32 (e.g., from the LiDAR data processing unit 40) and the scan data from the DAS 33 are input to a computer 42. The computer 42 includes a calibration vector storage device 44 (e.g., for storing calibration parameters and calibration protocols used to acquire CT scan data). The 3D measurement information obtained from the LiDAR scanning system 32 can be used to determine the calibration parameters utilized. The computer 42 also includes a data correction unit 46 for processing or correcting the CT scan data from the DAS 33. The computer 42 also includes an image reconstructor 48. The image reconstructor 48 receives sampled and digitized X-ray data from the DAS 33 and performs high-speed reconstruction. The reconstructed image is applied as input to the computer 42, which stores the image in a mass storage device 50. The computer 42 also receives commands and scan parameters from an operator through a console 52. An associated display 54 allows the operator to observe the reconstructed image as well as the 3D measurement data and other data from the computer 42. The computer 42 uses the commands and parameters provided by the operator to provide control signals and information to the DAS 33, the X-ray controller 28, the gantry motor controller 30, and the LiDAR controller 38. In addition, the computer 42 operates the table motor controller 56, which controls the motorized table 36 to position the patient 22 relative to the gantry 12. Specifically, the table 36 (via the support 23 supporting the patient 22) moves portions of the patient 22 through the gantry opening or aperture 58. In certain embodiments, the table 36 may include a tactile transducer 59 to help guide the patient 22 to position itself for scanning. For example, a brief vibration felt by the patient 22 through the tactile transducer 59 may indicate that the position for scanning is incorrect, while a prolonged vibration may indicate that the position is correct, or vice versa.

[0038] The computer 42 and the LiDAR processor unit 40 may each include a processing circuit. The processing circuit may be one or more general or special purpose microprocessors. The processing circuit may be configured to execute instructions stored in a memory to perform various actions. For example, the processing circuit may be used to receive or obtain LiDAR data acquired by the LiDAR scanning system 32. In addition, the processing circuit may also generate 3D measurements of the patient 22. In addition, the processing circuit may utilize the 3D measurements in a subsequent workflow process for a CT scan of the patient performed by the CT imaging system 32.

[0039] For example, the processing circuit system is configured to receive data of the patient 22 acquired by the LiDAR scanning system 32 to generate a multi-dimensional (e.g., 2D or 3D) virtual image of the patient 22 representing the morphological features of the subject (e.g., from LiDAR-based data), so that the multi-dimensional virtual image representing the current position (e.g., current body posture) of the patient 22 positioned on the support 23 is displayed on the display 41, and instructions are provided on the display 41 so that the patient 22 can guide itself to the target position (target body posture) on the support so as to perform a CT scan with the CT imaging system. In some embodiments, the processing circuit system is configured to provide instructions to display the multi-dimensional virtual image (e.g., image) at the target position positioned on the support 23 together with the multi-dimensional virtual image at the current position positioned on the support 23 on the display 41. In some embodiments, the instructions can be provided by automatic voice commands, visible light, or tactile prompts. In some embodiments, the processing circuit system is also configured to perform template matching between the current position of the patient 22 and the target position. In some embodiments, the processing circuit system is also configured to provide a user-perceivable indication of whether the current position of the patient 22 matches the target position. In some embodiments, the user-perceivable indication is provided by color coding a shape (e.g., a linear shape such as a box) on a display 41, which is arranged to surround a virtual image in the current position positioned on the support 23. For example, when the current position of the patient 22 matches the target position, the shape can be displayed as a first color. When the current position of the subject does not match the target position, the shape can also be displayed as a second color (different from the first color). In some embodiments, the user-perceivable indication is a pointing arrow shown on the display 41 to assist the patient 22 in reaching the target position. In some embodiments, the processing circuit system is configured to provide additional instructions to the patient 22 to maintain the current position of the CT scan when the current position of the patient 22 does not match the target position. In some embodiments, the processing circuit system is configured to determine the target position based on the scanning protocol for the CT scan. The components of the LiDAR scanning system 32 and the display 41 (and in some embodiments, the tactile transducer 59) form a LiDAR-guided patient positioning device 62. It should be noted that the information provided by the LiDAR-based data can be utilized in other workflows (e.g., automatically adjusting the table height based on the isocenter offset used to scan the patient or calibration phantom).

[0040] In some embodiments, the processing circuit system can be used to adjust the height of the table 36 to align the isocenter of the gantry 12 with the center of the region of interest of the target (e.g., patient 22 or phantom). For example, in some embodiments, the processing circuit system is configured to landmark the target on the support 23 of the table 36 of the CT imaging system 10 disposed outside the aperture 58 of the gantry 12. In some embodiments, the processing circuit system is configured to perform a LiDAR scan on the target. The LiDAR scan is performed using the LiDAR scanning system 32. The LiDAR scan is performed before a CT scan (e.g., a calibration scan or a diagnostic scan).

[0041] In some embodiments, the processing circuit system is configured to obtain or receive LiDAR data from the LiDAR scan. The LiDAR data represents light images of different views acquired at different angular positions (e.g., relative to the rotation axis 24). In some embodiments, the processing circuit system is configured to process the LiDAR data.

[0042] In some embodiments, the processing circuit system is configured to perform segmentation on the 3D information (3D point cloud data) to generate 3D point cloud information of the target. In some embodiments, the segmentation of the 3D information is performed using density based spatial clustering of applications with noise (DBSCAN). The 3D point cloud information of the patient represents the high-fidelity morphological features of the target.

[0043] In certain embodiments, the processing circuit system is configured to estimate the center of the region of interest of the target. Estimating the center of the region of interest may include setting landmarks as needed and separating the region of interest from the segmented 3D information of the target. The separated region of interest may be a two-dimensional (2D) contour representation of the selected surface of the region of interest. The center of the region of interest can be determined based on the 2D contour representation of the region of interest of the target. In certain embodiments, estimating the center of the region of interest of the target includes estimating the center of mass attenuation of the region of interest of the patient. In this embodiment, when separating the region of interest (2D contour representation), the position of the region of interest can be determined based on the anatomical model. The anatomical model can be used to estimate the center of mass attenuation of the patient. In certain embodiments, the anatomical model is scaled using LiDAR data.

[0044] In some embodiments, the processing circuitry is configured to obtain isocenter coordinate information from CT imaging system 10. The isocenter coordinate information includes the isocenter of gantry 12. In some embodiments, the processing circuitry is configured to calculate an offset between a center of a region of interest of the object and the isocenter of gantry 12.

[0045] In some embodiments, the processing circuit system is configured to provide a prompt to the operator (e.g., on a console (e.g., a display) of the CT imaging system 10) to adjust the height of the table 36 by the determined offset amount so that the isocenter of the gantry 12 is aligned with the center of the region of interest of the target. In response, the processing circuit system receives the operator's input to adjust the height of the table 36 through an input device of the console. In some embodiments, the processing circuit system is configured to automatically move the table 36 by the determined offset amount (i.e., adjust the height of the table 36) so that the isocenter of the gantry 12 is aligned with the center of the region of interest of the target. Adjusting the height of the table 36 to align the isocenter of the gantry 12 with the center of the region of interest of the target (e.g., patient 22) improves portion optimization.

[0046] In some embodiments, when the table is adjusted, the processing circuit system is configured to start a scan. In some embodiments, the scan is a CT diagnostic scan performed on a patient. In some embodiments, the scan is a CT calibration scan performed using a phantom.

[0047] Figure 3 is a flow chart of a method 64 for acquiring and utilizing LiDAR data for positioning. The method 64 may be Figure 1 and Figure 2 The LiDAR scanning system 32 and / or one or more components (e.g., processing circuitry) of the CT imaging system 10 may be executed simultaneously and / or in different Figure 3 One or more steps of method 64 are performed in the order shown.

[0048] At the start of method 64 (block 66), method 64 includes performing a LiDAR scan (e.g., using Figure 1 and Figure 2 The LiDAR scanning system 32 in the CT imaging system) (block 68). When the target is positioned on the gantry of the CT table of the CT imaging system, a LiDAR scan is performed. The LiDAR scan occurs before the scan.

[0049] The method 64 also includes using the LiDAR-based data of the target to guide the positioning of the target (block 70). The LiDAR-based data is processed (e.g., segmented and tracked) in real time (e.g., almost immediately when the data is collected or acquired) to form a 3D point cloud that characterizes high-fidelity topographic features of the target. The 3D point cloud contains real-time position information. In some embodiments, the real-time position information of the 3D point cloud data can be processed and viewed in real time to interactively guide the patient to position himself for subsequent scanning. In some embodiments, the 3D point cloud data can be used to identify the center of the target to calculate the offset from the isocenter and adjust the table height accordingly.

[0050] When using LiDAR-based data to guide the positioning of the target, the method 64 includes performing a scan (box 72). The scan can be a CT diagnostic scan or a CT calibration scan. The method 64 includes determining whether the process is complete (box 74). If the process is not complete, the method 64 returns to performing a LiDAR scan on the target (box 68). If the process is complete, the method 64 ends (box 76).

[0051] Figure 4 is a flow chart of a method 78 for acquiring and utilizing LiDAR for patient positioning (eg, using an external display). The method 78 may be performed by Figure 1 and Figure 2 The LiDAR scanning system 32 and / or one or more components (e.g., processing circuitry) of the CT imaging system 10 may be executed simultaneously and / or in different Figure 4 One or more steps of method 78 are performed in the order shown.

[0052] Upon initiation of the method 78 (block 80), the method 78 includes performing a LiDAR scan of a patient (eg, subject) disposed on a support of a table of a CT imaging system outside of an aperture of a gantry (block 82). Figure 1 and Figure 2 The LiDAR scanning system 32 is shown to perform the LiDAR scan. The LiDAR scan is performed before the CT scan (eg, a calibration scan or a diagnostic scan).

[0053] The method 78 also includes obtaining or receiving LiDAR data from the LiDAR scan (block 84). The LiDAR data represents the LiDAR scans at different angular positions (e.g., relative to the Figure 2The method 78 also includes processing the LiDAR data (block 86). Processing the LiDAR includes combining the LiDAR data and generating 3D information (i.e., 3D measurements) of the patient such as 3D point cloud data. Processing the LiDAR data may also include changing the coordinate system, checking point components and values, tiling the LiDAR data, trimming points outside defined boundaries, reducing the number of points, segmenting by component value, filtering the LiDAR data, and / or other processing techniques. These processing techniques may be performed before and / or after generating the 3D information.

[0054] The method 78 also includes performing segmentation on the multidimensional information (e.g., 3D point cloud data) to generate 3D point cloud information of the patient (box 88). In some embodiments, the segmentation of the 3D information is performed using density based spatial clustering of applications with noise (DBSCAN). The 3D point cloud information of the patient represents the high-fidelity topographic features of the patient. The 3D point cloud information of the patient includes real-time position information that can be processed and viewed in real time, thereby interactively guiding the patient to position himself for CT scanning. The method 78 further includes generating a virtual anatomical representation of the patient (e.g., a multi-dimensional virtual image) (box 90).

[0055] The method 78 also includes causing a multi-dimensional virtual image positioned on the support and representing the patient's current (real-time) position (eg, current posture) to be displayed (in real-time) on an external display (eg, Figure 2 and Figures 5 to 941 in the scanning room) (frame 92). Method 78 also includes providing instructions on the display so that the patient can guide himself to the target position (e.g., target posture) on the support for CT scanning (frame 94). In some embodiments, the target position is determined based on the scanning protocol for the upcoming CT scan. In some embodiments, providing instructions on the display includes displaying a multi-dimensional virtual image at the target position on the support together with a multi-dimensional virtual image at the current position positioned on the support on the display (e.g., side by side). In some embodiments, these on-screen instructions may be accompanied by automatic audio instructions (e.g., by a speaker associated with an external display or elsewhere in the scanning room) to guide the patient to position himself. In some embodiments, these on-screen instructions may be accompanied by visible light prompts (e.g., by LED lights associated with a workbench, a CT scanner, and / or a scanning room) to guide the patient to position himself. In some embodiments, these on-screen instructions may be accompanied by tactile prompts or signals, which are provided by a tactile transducer in the workbench where the patient is located to guide the patient to position himself. In certain embodiments, one or more of these automated voice commands, visible light cues, and tactile cues may be combined with or replace on-screen instructions.

[0056] Method 78 includes template matching between the patient's current (real-time) position and the target position (frame 96). Method 78 includes determining whether it matches (i.e., the current position matches the target position) (frame 98). Regardless of whether it matches, method 78 includes providing a user-perceivable indication of whether the patient's current position matches the target position (frame 100). In some embodiments, a user-perceivable indication is provided by color coding a shape on a display (e.g., a straight shape such as a box), which is arranged to surround a multi-dimensional virtual image in the current position positioned on a support. In some embodiments, the shape is displayed as a first color (e.g., green) when the patient's current position matches the target position, and the shape is displayed as a second color (e.g., red) when the patient's current position does not match the target position. In some embodiments, the user-perceivable indication is a pointing arrow shown on the display to assist the subject in reaching the target position. In addition or alternatively, one or more of an automatic voice command, a visible light prompt, and / or a tactile prompt can be used to provide an indication of whether the patient's current position matches the target position. In addition to providing a user-perceivable indication related to the match, when the patient's current position does not match the target position, the method 78 returns to performing the LiDAR scan and repeating the method 78 (block 82). In addition to providing a user-perceivable indication, when the patient's current position matches the target position, the method 78 includes providing the patient with additional instructions to maintain the current position of the CT scan when the scan will begin (box 102). The additional instructions may be provided on a screen of an external display or audibly. When these additional instructions are provided, the method 78 ends (box 104).

[0057] Figure 5 yes Figure 1 FIG. 1 is a schematic diagram of a CT imaging system 10 in FIG. 1 , which is coupled to an external display 41 (eg, a monitor) that provides patient positioning guidance. Figure 1 and Figure 2 As shown. Figure 5 As shown, the external display 41 is coupled to the gantry housing 13 via the robotic arm 106. In some embodiments, the display 41 is not coupled to the CT imaging system 10. Prior to scanning, the patient 22 is placed on the support 23 while the LiDAR scanning system 32 acquires LiDAR-based data of the patient 22. Figure 4 The LiDAR-based data is processed and utilized as described in method 78 in the embodiment of the present invention. The display 41 is positioned so that the screen 108 of the display 41 is visible to the patient 22 on the support 23. Figure 5As shown, a multi-dimensional virtual image of the patient 22 in the current (real-time) position (represented by reference numeral 110) disposed on the support 23 is shown on the screen 108 to provide guidance to the patient 22 in positioning himself on the support 23. In some embodiments, as Figure 6 As shown, an image of a multi-dimensional avatar of the patient 22 arranged on the support 23 in a target position (represented by reference numeral 112) is shown on the screen 108 to provide further guidance. The image 112 representing the target position is arranged together with the multi-dimensional avatar in the current position represented by reference numeral 110 (e.g., side by side).

[0058] Figure 7 and Figure 8 FIG. 1 is a schematic diagram of a screen 108 on an external display 41 of a CT imaging system 10 providing positioning guidance. Figure 7 and Figure 8 In FIG. 1 , a display 110 shown on the screen shows a multi-dimensional avatar of the patient in the current (real-time) position on the support. An image 112 representing a multi-dimensional avatar of the patient in the target position disposed on the support is shown on the screen 108 together with the display 110 . Figure 7 The display 110 in FIG. 1 shows (via a multi-dimensional avatar) that the patient's current position is incorrect relative to the target position. Figure 8 The display 110 in (via a multi-dimensional avatar) shows that the patient's current position is incorrect relative to the target position. Figure 7 and Figure 8 In the embodiment, a shape 114 (e.g., a box) is arranged around the visualization 110. In some embodiments, the shape 114 is color coded. For example, because the patient's current position is incorrect, Figure 7 and Figure 8 The shape 114 in FIG. 1 may be shown as a first color (e.g., red) to indicate that the position is incorrect. The shape 114 in a second color (e.g., green) different from the first color indicates that the patient is correctly positioned (i.e., matches the target position). Fig. 9 , the patient 22 is correctly positioned. Therefore, the color of the shape 114 arranged to surround the display 110 on the screen 108 is set to a second color (eg, green) to indicate that the position of the patient 22 is correct.

[0059] Fig.10 is a flow chart of a method 116 for centering a target for scanning. The method 116 may be performed by Figure 1 and Figure 2 The LiDAR scanning system 32 and / or one or more components (e.g., processing circuitry) of the CT imaging system 10 may be executed simultaneously and / or in different Fig.10One or more steps of method 116 are performed in the order shown.

[0060] At the start (block 118), the method 116 includes landmarking a target on a support of a table of a CT imaging system disposed outside of an aperture of a gantry (block 120). In some embodiments, the target is a patient. In some embodiments, the target is a phantom. The method 116 also includes performing a LiDAR scan of the target (block 122). Figure 1 and Figure 2 The LiDAR scanning system 32 is shown to perform the LiDAR scan. The LiDAR scan is performed before the CT scan (eg, a calibration scan or a diagnostic scan).

[0061] The method 116 also includes obtaining or receiving LiDAR data from the LiDAR scan (block 124). The LiDAR data represents the LiDAR scans at different angular positions (e.g., relative to the Figure 2 The method 116 also includes processing the LiDAR data (block 126). Processing the LiDAR includes combining the LiDAR data and generating 3D information (i.e., 3D measurements) of the target, such as 3D point cloud data. Processing the LiDAR data may also include changing the coordinate system, checking point components and values, tiling the LiDAR data, trimming points outside defined boundaries, reducing the number of points, segmenting by component value, filtering the LiDAR data, and / or other processing techniques. These processing techniques may be performed before and / or after generating the 3D information.

[0062] The method 116 also includes performing segmentation on the 3D information (3D point cloud data) to generate 3D point cloud information of the target (box 128). In some embodiments, the segmentation of the 3D information is performed using density based spatial clustering of applications with noise (DBSCAN). The 3D point cloud information of the patient represents the high-fidelity topographic features of the target.

[0063] The method 116 even includes estimating the center of the region of interest of the target (box 130). Estimating the center of the region of interest may include setting landmarks as needed and separating the region of interest from the segmented 3D information of the target. The separated region of interest may be a two-dimensional (2D) contour representation of the selected surface of the region of interest. The center of the region of interest may be determined based on the 2D contour representation of the region of interest of the target. In some embodiments, estimating the center of the region of interest of the target includes estimating the center of mass attenuation of the region of interest of the patient. In this embodiment, when separating the region of interest (2D contour representation), the position of the region of interest may be determined based on an anatomical model. The anatomical model may be used to estimate the center of mass attenuation of the patient. In some embodiments, the anatomical model is scaled using LiDAR data.

[0064] The method 116 further includes obtaining isocenter coordinate information from the CT imaging system (block 132). The isocenter coordinate information includes the isocenter of the gantry. The method 116 also includes calculating an offset between the center of the region of interest of the target and the isocenter of the gantry (block 134).

[0065] In some embodiments, method 116 includes providing a prompt to the operator (e.g., on a console (e.g., a display) of the CT imaging system) to adjust the height of the table by the determined offset amount so that the isocenter of the gantry is aligned with the center of the region of interest of the target (box 136). In response, the processing circuit system receives input from the operator to adjust the height of the table through an input device of the console. In some embodiments, method 116 includes automatically moving the table by the determined offset amount (i.e., adjusting the height of the table) so that the isocenter of the gantry is aligned with the center of the region of interest of the target (box 138). Adjusting the height of the table to align the isocenter of the gantry with the center of the region of interest of the target (e.g., patient) improves portion optimization.

[0066] When the table is adjusted, the method 116 includes starting a scan (block 140). In some embodiments, the scan is a CT diagnostic scan performed on a patient. In some embodiments, the scan is a CT calibration scan performed using a phantom. When the scan is started, the method 116 ends (block 142).

[0067] Fig.11 is a schematic diagram showing the visualization of acquired 3D LiDAR data of a patient and the characterization of segmented 3D LiDAR data. Fig.11 On the left, the patient is scanned by a LiDAR scanning system (e.g., Figure 1 and Figure 2 A representation 144 of the acquired 3D LiDAR data of the patient on the workbench obtained by the LiDAR scanning system 32). Fig.11 , a representation 146 of the segmented 3D LiDAR data. The representation 146 of the segmented 3D LiDAR data is obtained by performing 3D segmentation on the 3D LiDAR point cloud data. In certain embodiments, Density-Based Spatial Clustering of Applications with Noise (DBSCAN) is used to perform the segmentation.

[0068] Fig.12 1 is a schematic diagram of components for determining the center of a region of interest of a patient. Representation 148 represents the setting of landmarks 150, and the landmarks separate the region of interest 152 in a segmented 3D representation 154 of the patient obtained from 3D LiDAR point cloud data. Representation 156 represents the segmented point cloud (e.g., of the region of interest) used for monitoring (i.e., determining the center). Representation 158 is a 2D contour representation of a selected surface of the region of interest, wherein the center is calculated from the 2D contour representation.

[0069] Fig.13 is a schematic diagram illustrating the calculation of isocenter positioning offset using an automatic table height adjustment function for a patient undergoing a CT scan (eg, a diagnostic scan). Fig.13 As shown, a 2D contour representation 158 of a selected surface of a patient's region of interest relative to the orifice 58 of the gantry is shown from an axial end. Fig.13 As shown, a fitted line 160 is applied to the 2D contour representation 158. Point 162 represents the isocenter of the gantry. Point 164 represents the center of the patient's calculated region of interest. Fig.13 1, the offset 166 between the isocenter 162 of the gantry and the center 164 of the calculated region of interest of the patient is shown. As described above, the offset 166 is used to (e.g., automatically) adjust the height of the table for scanning the patient (e.g., CT diagnostic scanning).

[0070] Fig.14 is a schematic diagram showing the calculation of isocenter positioning offset using the automatic table height adjustment function of a phantom for performing a CT calibration scan. Fig.14 As shown, a 2D contour representation 168 of a selected surface of a region of interest of a phantom 170 is shown relative to the orifice 58 of the gantry from an axial end. In some embodiments, the phantom 170 is placed on a workbench. In some embodiments, a phantom bracket is used to attach the phantom 170 to the workbench. Fig.14 As shown, a fitted line 172 is applied to the 2D contour representation 168. Point 174 represents the isocenter of the gantry. Point 176 represents the center of the calculated region of interest of the phantom 170. Fig.141, the offset 178 between the isocenter 174 of the gantry and the center 176 of the calculated region of interest of the phantom 170 is calculated. As described above, the offset 178 is used to (e.g., automatically) adjust the height of the table for scanning the phantom 170 (e.g., a CT calibration scan).

[0071] Fig.15 1 is a schematic diagram of components for determining a center of mass attenuation of a region of interest of a patient. Representation 180 represents a setting of landmarks 182 that delimit a region of interest 184 in a segmented 3D representation 186 of a patient obtained from 3D LiDAR point cloud data. Representation 188 represents a segmented point cloud (e.g., of a region of interest) for monitoring (i.e., determining a center). In certain embodiments, estimating a center of mass attenuation of a region of interest of a target includes estimating a center of mass attenuation of a region of interest of a patient. As shown in FIG. Fig.15 As shown, when the region of interest is separated (i.e., the separated point cloud 188), the location of the region of interest can be determined according to the anatomical model, as indicated by reference numeral 190. The anatomical model 190 can be used to estimate the center of mass attenuation of the patient. In certain embodiments, the anatomical model 190 is scaled using LiDAR data. Representation 192 is a 2D contour representation of the selected surface of the region of interest, wherein the center of mass attenuation is calculated according to the 2D contour representation.

[0072] The technical effects of the disclosed embodiments include providing a LiDAR-guided patient positioning device that guides and assists the subject in positioning himself for a CT scan. Specifically, the LiDAR-based data is used to guide the subject within the interactive virtual visual device to improve the overall efficiency and robustness of the workflow using the CT scanner. High-fidelity positional 3D data is generated based on the LiDAR data without projecting any markers or patterns on the subject. Therefore, data can be easily collected, and 3D point cloud information can be effectively used to improve the robustness of the CT data acquisition workflow process. This also enables technicians to leave the scanning room during patient positioning, thereby reducing the potential spread of any infectious diseases that the subject may have. The technical effect of the automatic workbench adjustment function also ensures portion optimization and automatic adjustment of the phantom during calibration. The technical effects of the disclosed embodiments achieve an easy and efficient workflow and / or portion optimization.

[0073] Reference is made to the technology presented and claimed herein and applied to physical and specific examples of a practical nature that clearly improves upon the present state of the art and, therefore, is not abstract, intangible, or purely theoretical. In addition, if any claim appended to the end of this specification contains one or more elements designated as "means for [performing] the function of ..." or "steps for [performing] the function of ...," it is intended that such elements be interpreted under 35 U.S.C. § 112(f). However, for any claim containing elements designated in any other manner, it is not intended that such elements be interpreted under 35 U.S.C. § 112(f).

[0074] This written description uses examples to disclose the subject matter, including the best mode, and also to enable those skilled in the art to practice the subject matter, including making and using any devices or systems and performing any included methods. The patentable scope of the subject matter is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insignificant differences from the literal language of the claims.

Claims

1. A medical imaging system, comprising: A computer tomography (CT) imaging system, the CT imaging system comprising: a frame having an aperture and being rotatable about a rotation axis; a table having a support and the aperture configured to move a subject to be imaged into and out of the gantry; a radiation source mounted on the gantry and configured to emit an X-ray beam; and a detector configured to detect the X-ray beam emitted by the radiation source; a display disposed adjacent to the workbench within the subject's field of view; a light detection and ranging (LiDAR) scanning system, the LiDAR scanning system being physically coupled to the CT imaging system, wherein the LiDAR scanning system is configured to acquire data of different angular positions of the subject relative to the rotation axis when the subject is disposed on the support; and A processing circuit system configured to receive the data acquired by the LiDAR scanning system to generate a multi-dimensional virtual image of the subject representing the morphological features of the subject, so that the multi-dimensional virtual image representing the current position of the subject positioned on the support is displayed on the display, and provide instructions on the display so that the subject can guide himself to the target position on the support so as to perform a CT scan using the CT imaging system.

2. The medical imaging system of claim 1, wherein: The processing circuit system is configured to provide the instructions to cause the multi-dimensional virtual image positioned on the support at the target position to be displayed on the display together with the multi-dimensional virtual image positioned on the support at the current position.

3. The medical imaging system of claim 2, wherein: The processing circuitry is also configured to template match the current position of the subject with the target position.

4. The medical imaging system of claim 3, wherein: The processing circuitry is also configured to provide a user-perceptible indication of whether the current position of the subject matches the target position.

5. The medical imaging system of claim 4, wherein: The user-perceptible indication is provided by color coding a shape on the display, the display being configured to surround the multi-dimensional avatar in the current position positioned on the support, and wherein the shape is displayed in a first color when the current position of the subject matches the target position, and wherein the shape is displayed in a second color different from the first color when the current position of the subject does not match the target position.

6. The medical imaging system of claim 4, wherein: A user-perceivable indication is a directional arrow shown on the display to assist the subject in reaching the target location.

7. The medical imaging system of claim 4, wherein: The processing circuitry is further configured to provide additional instructions to the subject to maintain the current position of the CT scan when the current position of the subject matches the target position.

8. The medical imaging system of claim 1, wherein: The processing circuitry is also configured to determine the target location based on a scan protocol used for the CT scan.

9. The medical imaging system of claim 1, wherein: The display is coupled to the housing.

10. A computer-implemented method, the computer-implemented method comprising: receiving, at a processor, data acquired with a light detection and ranging (LiDAR) scanning system physically coupled to a computed tomography (CT) imaging system of a subject to be imaged disposed on a support of a table, wherein the table is configured to move the subject into and out of an aperture of a gantry of the CT imaging system; generating, by the processor, a multi-dimensional virtual image of the subject representing the morphological features of the subject; Displaying, by the processor, the multi-dimensional virtual image representing the current position of the subject positioned on the support on a display, wherein the display is arranged adjacent to the workbench within the field of view of the subject; and Instructions are provided on the display by the processor to enable the subject to guide himself to a target position on the support for CT scanning by the CT imaging system.

11. The computer-implemented method of claim 10, wherein: Providing the instruction includes causing the multi-dimensional virtual image positioned on the support at the target position to be displayed on the display together with the multi-dimensional virtual image positioned on the support at the current position.

12. The computer-implemented method of claim 11, further comprising template matching, by the processor, the current position of the subject to the target position.

13. The computer-implemented method of claim 12, further comprising providing, by the processor, a user-perceivable indication as to whether the current position of the subject and the target position match.

14. The computer-implemented method of claim 13, wherein: The user-perceptible indication is provided by color coding a shape on the display, the display being arranged to surround the multi-dimensional avatar in the current position positioned on the support.

15. The computer-implemented method of claim 14, wherein: The shape is displayed in a first color when the current position of the subject matches the target position, and the shape is displayed in a second color different from the first color when the current position of the subject does not match the target position.

16. The computer-implemented method of claim 13, further comprising providing, by the processor, additional instructions to the subject to maintain the current position of the CT scan when the current position of the subject matches the target position.

17. A non-transitory computer readable medium comprising processor executable code which, when executed by a processor, causes the processor to: receiving data acquired by a light detection and ranging (LiDAR) scanning system physically coupled to a computed tomography (CT) imaging system of a subject to be imaged disposed on a support of a table, wherein: The table is configured to move the subject into and out of an aperture of a gantry of the CT imaging system; Generate a multi-dimensional virtual image of the subject representing the morphological features of the subject; causing the multi-dimensional virtual image representing the current position of the subject positioned on the support to be displayed on a display, wherein the display is arranged adjacent to the workbench within the field of view of the subject; as well as Instructions are provided on the display to enable the subject to guide himself to a target position on the support for CT scanning with the CT imaging system.

18. The non-transitory computer readable medium of claim 17, wherein: Providing the instruction includes causing the multi-dimensional virtual image positioned on the support at the target position to be displayed on the display together with the multi-dimensional virtual image positioned on the support at the current position.

19. The non-transitory computer readable medium of claim 18, wherein: The processor executable code, when executed by the processor, further causes the processor to template match the current position of the subject with the target position.

20. The non-transitory computer readable medium of claim 19, wherein: The processor-executable code, when executed by the processor, further causes the processor to provide a user-perceptible indication of whether the current position of the subject matches the target position.

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