Guided breathing system for medical imaging

Abstract

To provide methods and systems for aiding a subject of a medical imaging examination in performing coached breathing.SOLUTION: In one embodiment, a method for a medical imaging system comprises generating a three-dimensional (3D) virtual representation of a portion of a surface of a chest and / or abdomen of a subject of the medical imaging system, the portion being adjustable in size by an operator of the medical imaging system; displaying, in real time, changes in the 3D virtual representation to the subject on a display device of the medical imaging system while the subject is breathing; displaying instructions to the subject on the display device to perform coached breathing in accordance with a selected breathing pattern, by using the 3D virtual representation as a guide; and, in response to detecting a deviation of a breathing pattern of the subject from the selected breathing pattern, indicating the deviation to the subject.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] FIELD OF THE INVENTION Embodiments of the subject matter disclosed herein relate to medical imaging systems. [Background technology]

[0002] In medical imaging systems, a scanner generates signals based on detected radiation that is used to form an image of the scanned subject's body. The radiation may include x-rays directed toward and attenuated by the subject in the case of computed tomography (CT) imaging, or radiation emitted by a radioactive tracer introduced into the subject in the case of positron emission tomography (PET), magnetic resonance (MR), and / or nuclear medicine (NM) imaging. The subject may be carefully positioned on the medical imaging system table to detect radiation from specific areas of interest on the patient's body while avoiding tissue in other areas. Because the quality of the resulting image may depend on the patient's body remaining stationary and motionless during the scan, movement of the patient's body during the scan may degrade image quality.

[0003] When a scan is performed on a patient's chest, movement of the patient's chest due to breathing can degrade image quality. As a result, patients can be instructed or coached to breathe in a manner that reduces movement of the patient's chest during the scan (e.g., coached breathing). However, patients may not follow instructions or may have difficulty controlling their breathing. For example, the patient's positioning within the medical imaging system may create or increase a level of anxiety in the patient, causing them to breathe more heavily and rapidly.

[0004] Current methods of guided breathing may rely on the presence of a technician, which can increase the cost of performing a scan. Additionally, personalized instruction increases the amount of time used to prepare the patient for the scan, which can reduce utilization of the medical imaging system and cause scheduling delays.

[0005] Various approaches have been taken to reduce the reliance on human intervention in guided breathing by using visual aids to help users achieve control of their breathing. For example, U.S. Patent Application No. 20190366030 to Giap teaches using a motion detection system to capture real-time physical position data of a subject during a scan and displaying an avatar of the subject in a virtual environment representing the subject's real-time physical position, allowing the subject to adjust their physical position using the avatar as a guide. However, Giap's motion detection system relies on a computationally intensive virtual reality system and the placement of multiple locator tags and / or motion sensors on the subject's body, which can increase the cost of performing the scan, the utilization of computational resources, and the amount of patient preparation time.

[0006] Another approach involves generating a 3D visualization of a patient's chest in real time using surface contour data of the patient's chest. The 3D visualization may be displayed to the patient, who can then use it to control their breathing. For example, U.S. Patent No. 7,869,562 to Khamene teaches using an optical imaging system to create a mesh topology of the patient and displaying changes in the topology as biofeedback for the patient to reproduce a predetermined breathing state (e.g., guided breathing). International Publication No. WO 2021228703 also teaches using LiDAR to determine if the position of a patient's body part in a medical imaging system has shifted from a desired position and to use an interactive repositioning guide configured to advise the patient to perform the desired movement of the body part via audio and visual signals.

[0007] However, the inventors have recognized that current systems that generate 3D visualizations, such as the system of Khamene and [...], have problems. One problem with current systems is that the correspondence between the 3D visualization and the patient's respiratory regions may not be accurate enough to effectively guide the patient. In addition, the size and / or complexity of the optical or LiDAR imaging system used to generate the 3D visualization may increase the size and cost of the medical imaging system and / or the operating costs of the medical imaging system. The inclusion of an optical or LiDAR imaging system may increase the amount of data collected by the medical imaging system, and the inclusion of an optical or LiDAR imaging system may also increase the amount of processing performed by the medical imaging system, resulting in fewer memory and processing resources. Another disadvantage of current systems is that they may not generate 3D visualizations during the scan, when guided breathing may be most effective. In other words, although 3D visualization can be used to guide the patient prior to the scan, the patient's breathing may change during the scan without the patient being aware of the change. As a result, current systems may not result in a reduction in technician time and / or patient preparation time, and / or may not result in a reduction in patient movement and a corresponding improvement in image quality. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] US Patent Application Publication No. 20190366030 [Patent Document 2] U.S. Patent No. 7,869,562 [Patent Document 3] International Publication No. 2021228703 Summary of the Invention

[0009] The present disclosure addresses, at least in part, one or more of the problems set forth above by a method for a medical imaging system, the method including: generating a three-dimensional (3D) virtual representation of a portion of a thoracic and / or abdominal surface of a subject of the medical imaging system, the portion being dimensionally adjustable by an operator of the medical imaging system; displaying changes in the 3D virtual representation in real time to the subject on a display device of the medical imaging system while the subject is breathing; displaying instructions on the display device to the subject to perform coached breathing in accordance with a selected breathing pattern using the 3D virtual representation as a guide; and, in response to detecting a deviation of the subject's breathing pattern from the selected breathing pattern, indicating the deviation to the subject.

[0010] These and other advantages and features of the present description will become readily apparent from the following detailed description, taken alone or in conjunction with the accompanying drawings. It should be understood that the foregoing summary is provided to present various concepts in a simplified form that are further described in the detailed description. Such description is not intended to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Moreover, the claimed subject matter is not limited to implementations that solve any disadvantages described above or elsewhere in this disclosure. [Brief explanation of the drawings]

[0011] Various aspects of the present disclosure will be more clearly understood from a reading of the following detailed description and by reference to the drawings in which:

[0012] [Figure 1A] FIG. 1 is a diagram of an imaging system in accordance with one or more embodiments of the present disclosure. [Figure 1B] FIG. 1B illustrates an alternative configuration of the imaging system of FIG. 1A in accordance with one or more embodiments of the present disclosure. [Figure 1C] FIG. 1 is a diagram of a guided breathing system according to one or more embodiments of the present disclosure. [Figure 2] FIG. 1 is a block schematic diagram of an exemplary imaging system in accordance with one or more embodiments of the present disclosure. [Figure 3A] FIG. 1 is a block schematic diagram of a first workflow for performing scanning with guided breathing in accordance with one or more embodiments of the present disclosure. [Figure 3B] FIG. 10 is a block schematic diagram of a second alternative workflow for performing scanning with guided breathing in accordance with one or more embodiments of the present disclosure. [Figure 4] 1 is a flow chart illustrating an example high-level method for performing scanning with guided breathing in accordance with one or more embodiments of the present disclosure. [Figure 5A] 1 is a flow chart illustrating an example method for performing guided breathing in accordance with one or more embodiments of the present disclosure. [Figure 5B] 1 is a flow chart illustrating an example method for measuring chest movement of a subject during supervised breathing in accordance with one or more embodiments of the present disclosure. [Figure 6] 1 is a flow diagram illustrating an example method for acquiring and processing LiDAR data during guided breathing in accordance with one or more embodiments of the present disclosure. [Figure 7] 1 is a flow diagram illustrating an example method for acquiring image data during a medical imaging scan using guided breathing in accordance with one or more embodiments of the present disclosure. [Figure 8A] FIG. 1 illustrates a 3D virtual representation of a subject's chest in a scan generated in accordance with one or more embodiments of the present disclosure. [Figure 8B] 1 is a point cloud corresponding to points on a subject's chest detected using LiDAR generated in accordance with one or more embodiments of the present disclosure. [Figure 9] 8A and 8B are diagrams illustrating example displays of the 3D virtual representation of FIG. 8A and the point cloud of FIG. 8B on a display device generated for guided breathing in accordance with one or more embodiments of the present disclosure. [Figure 10] 1 is a graph showing a plot of a breathing pattern during guided breathing in accordance with one or more embodiments of the present disclosure.

[0013] The drawings illustrate certain aspects of the described systems and methods. Together with the following description, the drawings particularly illustrate and explain the structures, methods, and principles described herein. In the drawings, the dimensions of components may be exaggerated or otherwise modified for clarity. Well-known structures, materials, or operations have not been shown or described in detail so as not to obscure aspects of the described components, systems, and methods. DETAILED DESCRIPTION OF THE INVENTION

[0014] Descriptions and embodiments of the subject matter disclosed herein relate to methods and systems for improving the quality of medical images produced by a medical imaging system. The medical imaging system may be a computed tomography (CT) system, a positron emission tomography (PET) system, a magnetic resonance (MR) imaging system, a nuclear medicine (NM) imaging system, a PET / CT or PET / MR system, or a different type of imaging system. Prior to performing a scan, the subject to be scanned is typically placed on the table of the medical imaging system. The position of the table is adjusted by the medical imaging system operator to position the subject within the gantry. During the scan, subject movement can produce noise in the resulting images due to variations in the subject's position while signals are being generated at the detector array. As a result, the subject may be instructed to minimize movement to reduce the level of noise in the resulting images.

[0015] Minimizing subject movement may include coaching the subject's breathing, especially when the scan involves the subject's abdomen, chest, or other body parts that may move during breathing. To ensure image quality exceeds a threshold quality, the subject may be required to reproduce or follow a selected or targeted breathing pattern, referred to herein as coached breathing. The selected breathing pattern may be selected by the medical imaging system operator from multiple breathing patterns based, for example, on the scanning protocol, anatomical location, and / or subject characteristics (e.g., size and breath-holding ability). The breathing pattern may include deep breathing, shallow breathing, hyperventilation, breath-holding, or a combination of different types of breathing, including inhaling and exhaling different volumes of air. The selected breathing pattern may limit the range of motion of the abdomen, chest, or other body parts during inhalation and exhalation. Specifically, the subject may be instructed to minimize chest expansion during inspiration, minimize chest contraction during expiration, hold their breath for some amount of time, and / or breathe at a desired rate (e.g., slowly).

[0016] Typically, the subject is trained in guided breathing by the medical imaging system operator or technician or a caregiver prior to the scan. After the subject is able to reproduce the selected breathing pattern within the deviation threshold, the scan can be performed on the subject.

[0017] This document presents a method and system for a guided breathing system that can be integrated into a medical imaging system. An example of a medical imaging system that can be used to perform contrast-enhanced scans according to this technique is shown in Figures 1A and 2. The medical imaging system includes a guided breathing device that trains a subject to minimize movement of the medical imaging system during breathing. The guided breathing device can include a monitor coupled to the medical imaging system, as shown in Figure 1A. The guided breathing device can also include a head-mounted display, as shown in Figure 1B. According to a first workflow shown in Figure 3A, a first type of guided breathing device can be used to train the subject in a training room, as shown in Figure 1C, and a second type of guided breathing device included in the medical imaging system can be used to guide the subject during the scan. According to a second workflow shown in Figure 3B, a training room can be eliminated, and the subject can be trained and guided using the second type included in the medical imaging system. The subject can be trained and guided by following a procedure such as the method described in Figure 4. A subject can be trained according to one or more steps of the method of FIGS. 5A and 5B, which may rely on registering two or more sets of points, referred to herein as point clouds, representing the subject's surface contour using LiDAR, 3D cameras, or similar technology, as described in connection with the method of FIG. 6. An example point cloud is shown in FIG. 8B, where the point cloud is based on a selected portion of the surface contour as shown in FIG. 8A. Measured distances between two or more point clouds can be used to determine a target range of motion for the subject's chest. The target range of motion can be achieved by the subject by following breathing guide cues and / or breathing guide models displayed on a display device, as shown in FIG. 9. FIG. 10 shows an example graph of a first breathing pattern within the target range of motion and a second breathing pattern outside the target range of motion.

[0018] Additionally, it should be understood that references to the term "thorax" herein for purposes of this disclosure may include the abdominal portion of the subject without departing from the scope of this disclosure. As such, references to the subject's thorax should be interpreted as "thorax and / or abdomen."

[0019] 1A illustrates an exemplary computed tomography (CT) imaging system 100 configured for CT imaging. While the systems and methods disclosed herein are described with reference to a CT imaging system, it should be appreciated that the disclosed systems and methods may also be applied to other forms of medical imaging, such as magnetic resonance (MR) imaging, positron emission tomography (PET) imaging, single photon emission computed tomography (SPECT) imaging, nuclear medicine (NM) imaging, and / or other techniques without departing from the scope of this disclosure.

[0020] Specifically, CT imaging system 100 is configured to image a subject 112, such as a patient, an inanimate object, one or more manufactured parts, and / or foreign objects present in the body, such as dental implants, stents, and / or contrast media. In one embodiment, CT imaging system 100 includes a gantry 102, which in turn may further include at least one X-ray source 104 configured to project a beam of X-ray radiation 106 (see FIG. 2 ) that is used to image the subject 112 residing on a table 114. Specifically, X-ray source 104 is configured to project the beam of X-ray radiation 106 toward a detector array 108 located on the opposite side of gantry 102. While FIG. 1A depicts a single X-ray source 104, in some embodiments, multiple X-ray sources and detectors may be used to project multiple beams of X-ray radiation to acquire projection data at various energy levels corresponding to the patient. In some embodiments, the X-ray source 104 may enable dual-energy gemstone spectral imaging (GSI) with rapid peak kilovoltage (kVp) switching. In some embodiments, the X-ray detector used is a photon-counting detector capable of discriminating between X-ray photons of different energies. In other embodiments, two sets of X-ray sources and detectors are used, one set at a low kVp and the other at a high kVp, to create dual-energy projections. Thus, it should be appreciated that the methods described herein may be implemented for single-energy and dual-energy acquisition techniques.

[0021] In some embodiments, the CT imaging system 100 further includes an image processor unit 110 configured to reconstruct an image of a target volume of the subject 112 using an iterative or analytical image reconstruction method. For example, the image processor unit 110 may reconstruct an image of the target volume of the subject 112 using an analytical image reconstruction approach, such as filtered back projection (FBP). As another example, the image processor unit 110 may reconstruct an image of the target volume of the subject 112 using an iterative image reconstruction approach, such as advanced statistical iterative reconstruction (ASIR), conjugate gradient (CG), maximum likelihood expectation maximization (MLEM), and model-based iterative reconstruction (MBIR). As described in more detail herein, in some examples, the image processor unit 110 may use both an analytical image reconstruction approach, such as FBP, in addition to an iterative image reconstruction approach.

[0022] In some CT imaging system configurations, an x-ray source projects a cone-shaped beam of x-ray radiation, which is collimated to lie within the XYZ plane of a Cartesian coordinate system, commonly referred to as the "imaging plane." The x-ray radiation beam passes through an imaging object, such as a patient or subject. After being attenuated by the object, the x-ray radiation beam impinges on an array of detector elements. The intensity of the attenuated x-ray radiation beam received by the detector array depends on the attenuation of the x-ray radiation beam by the object. Each detector element in the array generates a separate electrical signal, which is a measure of the x-ray beam attenuation at the detector location. Attenuation measurements from all detector elements are acquired separately to generate a transmission profile.

[0023] In some medical imaging systems, the x-ray source and detector array are rotated with a gantry around the object in the imaging plane so that the angle at which the x-ray beam intersects the object is constantly changing. A group of x-ray radiation attenuation measurements, e.g., projection data, from the detector array at one gantry angle is called a "view." A "scan" of the object includes a set of views made at different gantry angles, or view angles, during one rotation of the x-ray source and detector.

[0024] As described in further detail herein, the CT imaging system 100 may be configured to train the subject 112 to reduce movement of the subject 112 during a scan. For example, the CT imaging system 100 may be configured to train the subject 112 to breathe (e.g., with guided breathing) in a manner that minimizes movement of the respiratory region of the subject 112 during a scan. For example, a scan may be performed on the abdomen of the subject 112, and abdominal movement due to breathing may degrade the quality of an image reconstructed from data acquired during the scan.

[0025] As such, CT imaging system 100 includes a coached breathing system. Some components of the coached breathing system may be integrated into CT imaging system 100, while other components of the coached breathing system may be separate from CT imaging system 100. For example, some components of the coached breathing system may be integrated into gantry 102, image processing unit 110, or a different component of CT imaging system 100. Furthermore, in some embodiments, a first type of coached breathing system may be integrated into CT imaging system 100, while a second type of coached breathing system may be separate from CT imaging system 100. For example, the second type of coached breathing system may be used to train subject 112 to control their breathing in a location different from CT imaging system 100 (e.g., a training room such as the training room shown in FIG. 1C ), and the first type of coached breathing system may be used by subject 112 to control their breathing during a scan performed using CT imaging system 100.

[0026] The guided breathing system includes a secondary imaging device 105 and a patient display device 130. In the illustrated embodiment, the secondary imaging device 105 is located inside the gantry 102. In other embodiments, the secondary imaging device 105 may be coupled to the exterior of the gantry 102. In one embodiment, the secondary imaging device 105 is a laser imaging detection and ranging (LiDAR) system. In another embodiment, the secondary imaging device 105 may be a 3D camera or a different type of remote sensing device.

[0027] The secondary imaging device 105 can capture the surface contours of body parts of the subject 112, such as the chest. The surface contours can be used to generate visualizations of these body parts and display them on the patient display device 130. This visualization can be used to train the subject 112 to maintain a still posture and minimize movement of these body parts during the scan. For example, the visualization can be used to train the subject 112 to control their breathing to reduce chest movement. The generation of the visualization is described in further detail below with reference to FIGS. 4 through 9.

[0028] The patient display 130 may be coupled to the gantry 102 via a movable arm 132. The patient display 130 may be coupled to the end of the movable arm 132 in a manner that allows the display to freely rotate in at least a first plane of movement indicated by the circular arrow 134. For example, the patient display 130 may be coupled to the end of the movable arm 132 via a hinge. In some embodiments, the patient display 130 may be coupled to the end of the movable arm 132 via a ball-and-socket joint or a similar type of coupling that allows the patient display 130 to freely rotate in additional planes of movement. The coupling of the patient display 130 to the movable arm 132 may allow the screen of the patient display 130 to be aimed at the subject 112, allowing the subject 112 to view the visualizations displayed on the patient display 130 when lying on the table 114 with minimal adjustment of the subject's 112's position on the table 114.

[0029] The movable arm 132 may be coupled to the gantry 102 in a manner that allows the movable arm 132 to rotate in the direction indicated by arrow 136. For example, the movable arm 132 may rotate from a first position 140 to a second position 141 in the direction indicated by arrow 136. The first position 140 may be a position where the patient display 130 is most visible to the subject 112 during a scan. The second position 141 may be a position where the patient display 130 is not visible to the subject 112 during a scan. For example, the position 141 may be a position where the patient display 130 is not distracting to the subject 112 and / or does not otherwise interfere with the CT imaging system 100, the subject 112, and / or the operator of the CT imaging system 100. In some embodiments, the movable arm 132 may rotate beyond the second position 141 in the direction indicated by arrow 138. For example, in some embodiments, the movable arm 132 may rotate 180 degrees or more from the first position 140.

[0030] In other embodiments, display device 130 may not be coupled to CT imaging system 100. For example, display device 130 may be located on a cart or included in the chassis of a mobile device or system that may be positioned in a suitable location adjacent table 114 and subject 112. Furthermore, in some embodiments, CT imaging system 100 may not include display device 130. For example, in some embodiments, feedback regarding the performance of guided breathing may be provided to subject 112 via one or more illuminated portions and / or lights located on inner surface 120 of gantry 102, edge 121 of gantry 102, or front surface 122 of gantry 102.

[0031] 1B illustrates an alternative configuration 150 of the CT imaging system 100 in which the guided breathing system includes a head-mounted display 180 and the visualization is displayed on the head-mounted display 180 rather than on the patient display 130. An advantage of displaying the visualization on the head-mounted display 180 rather than on the patient display 130 is that the subject 112 can view the visualization with their head in various positions (e.g., without having to tilt their head or twist their neck to view the visualization). Additionally, the subject 112 can view the visualization on the head-mounted display 180 at various positions on the table 114, including table positions where the subject's 112's head is located inside the gantry 102 and the display 130 may not be visible to the subject 112.

[0032] FIG. 1C illustrates a second type of coached breathing system 160, where the second type 160 is installed in a coached breathing exercise room 161. The coached breathing exercise room 161 includes a couch or table 173 on which the subject 112 may rest during training with the coached breathing system, which may be substantially similar to the table 114 of FIG. 1A. The subject 112 may be positioned on the couch 180 in a position substantially similar to the position of the subject 112 for scanning with the CT imaging system 100. Alternatively, the subject 112 may be positioned differently from that shown in FIG. 1C. For example, the subject 112 may be a pediatric patient, and the pediatric patient may be positioned on a different type of couch or chair.

[0033] In the illustrated embodiment, a secondary imaging device 164 is positioned above and / or near a chest 163 of the subject 112, and the display device 162 may be positioned and oriented such that the subject 112 can view the screen of the display device 162 while training with the guided breathing system. The secondary imaging device 164 and the display device 162 may be the same as or similar to the secondary imaging device 105 and the display device 130 of the CT imaging system 100. In one embodiment, the secondary imaging device 164 and the display device 162 are flexibly coupled to a rail 170 via a first movable arm 166 and a second movable arm 168, respectively, such that a first position of the secondary imaging device 164 and a second position of the display device 162 along the rail 170 can be adjusted to accommodate a variety of subjects of different sizes. For example, the first movable arm 166 and the second movable arm 168 may be slidably coupled to the rail 170 such that the first movable arm 166 and the second movable arm 168 may independently slide along the rail 170 in either of two directions indicated by arrow 174.

[0034] In some embodiments, the second type of guided breathing system 160 can include an LED light 172 that can be configured to indicate to the subject 112 whether the chest 163 of the subject 112 is within a desired range of motion due to breathing during training with the guided breathing system. The desired range of motion can be based on a breathing pattern, which can be defined by the range of motion of the chest 163, the breathing rate of the subject 112, and / or the ability of the subject 112 to hold a breath as instructed. For example, if the subject 112 is breathing at a first rapid or heavy breathing rate, the chest 163 may not be within the desired range of motion. As a result of the chest 163 not being within the desired range of motion, the LED light 172 can be turned on. If the subject 112 is breathing at a second slower, shallower breathing rate, the chest 163 may be within the desired range of motion, and the LED light 172 can be turned off. In other words, the difference in the position of the surface of the chest 163 relative to the secondary imaging device 164 between the subject's 112 expiration and the subject's 112 inspiration can be measured by the guided breathing system and the LED light 172 can be turned on or off based on whether this difference exceeds a threshold difference. The LED light 172 can indicate to the subject 112 when the movement of the chest 163 is within a desired range of motion and when the movement of the chest 163 is outside the desired range of motion. For example, in one embodiment, the LED light 172 can be illuminated as a green light when the movement of the chest 163 is within the desired range of motion and as a red light when the movement of the chest 163 is outside the desired range of motion. In this manner, by monitoring the LED light 172, the subject 112 can be trained to regulate their breathing to keep the movement of the chest 163 within the desired range of motion.

[0035] Instructions for performing coached breathing and following one or more breathing patterns may be displayed on display device 162. The instructions may include written instructions, auditory instructions, or both written and auditory instructions. Additionally, as described in more detail below, a visualization of the subject's breathing may be displayed on display device 162, which may assist the subject in performing coached breathing. Specifically, a first visualization of the subject's breathing may be displayed along with a second visualization of a selected breathing pattern, allowing the subject to adopt the selected breathing pattern by aligning the first visualization with the second visualization.

[0036] In various embodiments, subject 112 may be trained in a guided breathing training chamber 161 prior to a scan being performed on subject 112. After subject 112 has been trained to control his or her breathing sufficiently to keep chest 163 within a desired range of motion, a scan can be performed on subject 112. During the scan, subject 112 may monitor his or her breathing using one type of guided breathing system integrated into CT imaging system 100, as described above in connection with FIG. 1A.

[0037] FIG. 2 illustrates an exemplary CT imaging system 200, which may be the same as or similar to the CT imaging system 100 of FIG. 1A. According to aspects of the present disclosure, the CT imaging system 200 is configured to image a subject 204 (e.g., subject 112 of FIG. 1A). In one embodiment, the CT imaging system 200 includes a detector array 108 (see FIG. 1A). The detector array 108 further includes a plurality of detector elements 202 that collectively sense an x-ray radiation beam 106 (see FIG. 2) passing through the subject 204 (e.g., a patient) to acquire corresponding projection data. In some embodiments, the detector array 108 may be fabricated in a multi-slice configuration including multiple rows of cells or detector elements 202, where one or more additional rows of detector elements 202 are arranged in a parallel configuration to acquire projection data.

[0038] In some embodiments, CT imaging system 200 is configured to acquire desired projection data across different angular positions about object 204. Accordingly, gantry 102 and components mounted to gantry 102 may be configured to rotate about center of rotation 206 to acquire projection data at different energy levels, for example. Alternatively, in embodiments where the projection angle relative to object 204 changes as a function of time, these mounted components may be configured to move along a general curve rather than along the arc of a circle.

[0039] As the x-ray source 104 and detector array 108 rotate, the detector array 108 collects data of the attenuated x-ray beam. The data collected by the detector array 108 undergoes pre-processing and calibration to condition the data to represent line integrals of the attenuation coefficients of the scanned object 204. The processed data is generally referred to as a projection. In some examples, individual detectors or detector elements 202 of the detector array 108 may include photon-counting detectors that record individual photon interactions in one or more energy bins. It should be appreciated that the methods described herein may also be embodied as energy-integrating detectors.

[0040] The acquired set of projection data may be subjected to basis material decomposition (BMD). During BMD, the measured projections are converted into a set of material density projections. The material density projections may be reconstructed to form a pair or set of material density maps or images for each respective basis material, such as a bone map, a soft tissue map, and / or a contrast agent map. These density maps or images may then be correlated to form a 3D volumetric image of the basis materials, e.g., bone, soft tissue, and / or contrast agent, in the imaging volume.

[0041] Once reconstructed, the basis material images produced by the CT imaging system 200 represent internal features of the subject 204 expressed as the densities of two basis materials. The density images may be displayed to show these features. In a traditional approach to diagnosing medical conditions, such as disease states, or more generally medical phenomena, a radiologist or physician examines a hard copy or display of the density images to identify specific features of interest. Such features may include lesions, size and shape of specific anatomical regions or organs, and other features discernible in the images based on the skill and expertise of the individual physician.

[0042] In one embodiment, the CT imaging system 200 includes a control mechanism that controls movement of components such as the rotation of the gantry 102 and the operation of the x-ray source 104. In some embodiments, the CT imaging system 200 includes an x-ray controller 210 configured to provide power and timing signals to the x-ray source 104. Additionally, the CT imaging system 200 includes a gantry motor controller 212 configured to control the rotational speed and / or position of the gantry 102 based on imaging requirements.

[0043] In some embodiments, the CT imaging system 200 further includes a data acquisition system (DAS) 214 configured to sample analog data received from the detector elements 202 and convert the analog data to digital signals for subsequent processing. The DAS 214 may be further configured to selectively sum analog data from a subset of the detector elements 202 into a so-called macro-detector, as described in more detail herein. The data sampled and digitized by the DAS 214 is transmitted to a computer or computing device 216. In one example, the computing device 216 stores the data in a storage or mass storage device 218. The storage device 218 may be any type of non-transitory memory and may include, for example, a hard disk drive, a floppy disk drive, a compact disk read / write (CD-R / W) drive, a digital versatile disk (DVD) drive, a flash drive, and / or a solid-state storage drive.

[0044] Additionally, the computing device 216 provides commands and parameters to one or more of the DAS 214, the X-ray controller 210, and the gantry motor controller 212 to control system operations, such as data acquisition and / or processing. In some embodiments, the computing device 216 controls system operations based on operator input. The computing device 216 receives operator input, including, for example, commands and / or scanning parameters, via an operatively coupled operator console 220. The operator console 220 may include a keyboard (not shown) or a touch screen that allows an operator to specify commands and / or scanning parameters.

[0045] 2 shows one operator console 220, more than one operator console may be coupled to CT imaging system 200, for example, to input and output system parameters, request exams, plot data, and / or view images. Additionally, in some embodiments, CT imaging system 200 may be coupled to multiple displays, printers, workstations, and / or similar devices, which may be located locally, e.g., within a facility or hospital, or remotely, e.g., at entirely different locations via one or more configurable wired and / or wireless networks, such as the Internet and / or virtual private networks, wireless telephone networks, wireless local area networks, wired local area networks, wireless wide area networks, and wired wide area networks.

[0046] In one embodiment, for example, CT imaging system 200 includes or is coupled to a Picture Archiving and Communication System (PACS) 224. In one implementation, PACS 224 is further coupled to a remote system, such as a radiology information system, a hospital information system, and / or a local or external network (not shown), to enable operators at various locations to provide commands and parameters and / or obtain image data.

[0047] The computing device 216 uses operator-provided and / or system-defined commands and parameters to operate the table motor controller 226, which in turn can control the table 114, which can be a motorized table. Specifically, the table motor controller 226 can move the table 114 to properly position the subject 204 in the gantry 102 to acquire projection data corresponding to a target volume of the subject 204.

[0048] As previously described, DAS 214 samples and digitizes the projection data acquired by detector elements 202. Image reconstructor 230 then performs high-speed reconstruction using the sampled and digitized x-ray data. While FIG. 2 depicts image reconstructor 230 as a separate entity, in some embodiments, image reconstructor 230 may form part of computing device 216. Alternatively, image reconstructor 230 may not be present in CT imaging system 200, and instead computing device 216 may perform one or more functions of image reconstructor 230. Also, image reconstructor 230 may be located locally or remotely and may be operatively connected to CT imaging system 200 using a wired or wireless network. Specifically, an example embodiment may utilize the computational resources of a “cloud” network cluster for image reconstructor 230.

[0049] In one embodiment, image reconstructor 230 stores the reconstructed images in memory 218. Alternatively, image reconstructor 230 can transmit the reconstructed images to computing device 216 for generating patient information useful for diagnosis and evaluation. In some embodiments, computing device 216 may transmit the reconstructed images and / or patient information to a display or display device 232 communicatively coupled to computing device 216 and / or image reconstructor 230. In some embodiments, the reconstructed images may be transmitted from computing device 216 or image reconstructor 230 to memory 218 for short-term or long-term storage.

[0050] CT imaging system 200 includes a coached breathing system 208, which may be a non-limiting example of the coached breathing system described above in connection with FIGS. 1A, 1B, and 1C. In addition to secondary imaging device 105 and patient display device 130, coached breathing system 208 includes a secondary imaging device controller 240 and a position data processing unit 242. Secondary imaging device controller 240 may be configured to control secondary imaging device 105. In various embodiments, secondary imaging device 105 can cover a 360-degree view of each portion of subject 112 within gantry 102. In some embodiments, multiple secondary imaging devices 105 may be positioned at different positions around gantry 102 such that each 360-degree view of each portion of subject 112 within gantry 102 is covered by multiple secondary imaging devices 105.

[0051] The position data processing unit 242 may be coupled to the secondary imaging device 105. The position data processing unit 242 may receive image data from the secondary imaging device 105 and may process this image data to determine whether the range of motion of one or more respiratory regions of the subject of the scan (e.g., the chest and abdomen of the subject 112, etc.) exceeds a threshold range of motion during the subject's inspiration and expiration. If the range of motion exceeds the threshold range of motion, the subject may be instructed, using visualizations displayed on the patient display device 130 as described above, to adjust their breathing to reduce the movement of their one or more respiratory regions. The processing of image data by the position data processing unit 242 is described in further detail below in connection with Figures 4 through 7.

[0052] FIG. 3A illustrates a first workflow 300 of how a coached breathing system, such as coached breathing system 208 of FIG. 2, can operate. In the first workflow 300, in a first block 302, a subject of a medical imaging system (e.g., subject 112 of CT imaging system 100) can be trained with the coached breathing system prior to performing a scan. During training, the subject can view an interactive visualization of a portion of the subject's chest on a display screen, such as the screen of display device 162 described above with reference to FIG. 1C or a head-mounted display, such as head-mounted display 180 described above with reference to FIG. 1B. As described in further detail below, the interactive visualization can include a 3D virtual representation of the surface of the subject's chest while the subject is breathing. As the subject is breathing, the interactive visualization can change to show the subject how their chest moves during breathing. For example, the 3D virtual representation can expand during the subject's inhalation and contract during the subject's exhalation.

[0053] The subject can change their breathing pattern, i.e., the manner in which they breathe, and indicate this change via the 3D virtual representation. The interactive visualization can indicate a target or reference position on the 3D virtual representation and / or can indicate a desired (e.g., threshold) range of motion (e.g., expansion and contraction) of the chest. In this manner, by viewing their breathing along with the target or reference position in the interactive visualization, the subject can adjust their breathing to match the target or reference position. Matching the target or reference position can include not allowing the chest to expand beyond a first distance threshold from the target position and / or not allowing the chest to contract beyond a second distance threshold from the target position. In this manner, the subject can learn to breathe in a manner that minimizes movement of the respiratory parts of their body, thereby preventing possible noise and improving the quality of images reconstructed from the scan.

[0054] As an example, a subject may experience anxiety in anticipation of a CT scan. As a result of the anxiety, the subject may breathe irregularly, heavily, deeply, or rapidly. Because performing a scan on a subject while the subject is breathing irregularly, heavily, deeply, or rapidly can introduce noise artifacts into the images obtained from the scan due to excessive movement of the subject's chest, a guided breathing system can be used to train the subject to control their breathing. A 3D camera, LiDAR laser, or similar remote sensing technology can be positioned above the subject's chest to capture the surface contour of the chest. The surface contour can be displayed on a display device via an interactive visualization that allows the subject to visualize the movement of their chest while breathing.

[0055] Viewing the interactive visualization can help the subject control their breathing. For example, the subject may view a 3D virtual representation of their chest expanding during inspiration. The interactive visualization can indicate that chest expansion has exceeded a desired (e.g., threshold) expansion. For example, a visual component of the interactive visualization can illuminate or brighten to indicate excessive expansion. Additionally or alternatively, an LED light on or near the indicator (LED light 172 in FIG. 1C ) may illuminate to indicate excessive expansion. As a result of viewing excessive expansion, the subject can attempt to reduce inspiration to reduce chest movement.

[0056] In various embodiments, training with the coached breathing system may occur at a location separate from the medical imaging system. For example, training with the coached breathing system may occur in a coached breathing exercise room, such as coached breathing exercise room 161 in FIG. 1C . An advantage of training the subject in the coached breathing exercise room rather than the medical imaging system is that it may reduce the subject's level of anxiety due to anticipation of the scan. Additionally, the amount of time available for the subject to train in the coached breathing exercise room may be greater than the amount of time available for training with the medical imaging system, due to better utilization of the medical imaging system.

[0057] Once the subject has been trained, in a second block 304 of the first workflow 300, the subject may be positioned on a medical imaging system table (e.g., table 114) in an appropriate position for scanning. For example, if the subject's heart or abdomen is to be scanned, the subject may be positioned supine on the table. The subject may be landmarked to assist the operator in aligning the medical imaging system's X-ray source (e.g., X-ray source 104) with the subject's anatomical region of interest (ROI). Positioning the subject on the table may include adjusting the position of the table to insert the portion of the subject's body containing the ROI into the imaging plane of the gantry.

[0058] Once the subject is properly positioned for scanning, in third block 306 of first workflow 300, the subject can practice and / or be instructed on coached breathing using the coached breathing system. For example, the subject can view one type of interactive visualization described above on a display device coupled to the medical imaging system (e.g., patient display device 130 of FIG. 1A ). Alternatively, the interactive visualization may be displayed on a head-mounted display, for example, if the subject is positioned inside the gantry of the medical imaging system and the display device is not visible to the subject. The subject can practice coached breathing with the aid of the visualization until their chest movement is within a threshold motion range defined by a target or reference position.

[0059] When the subject's chest motion falls within the threshold motion range, the scan can be performed in fourth block 308 of the first workflow 300. In various embodiments, the subject can continue to practice guided breathing while the scan is being performed to ensure that their body motion is minimized.

[0060] FIG. 3B illustrates a second workflow 350 for how the coached breathing system operates. In the second workflow 350, the subject may not be trained prior to being placed on the table of the medical imaging system. For example, a coached breathing training room may not be available to train the subject, the operator of the medical imaging system may determine that the amount of time suggested for training the subject is too short to warrant using a coached breathing training room, or for a different reason. Thus, according to the second workflow 350, in a first block 302, the subject is placed on the table of the medical imaging system and landmarked; in a second block 352, the subject can be trained in the coached breathing system as described above while placed on the table of the medical imaging system; in a third block 354, the subject can practice coached breathing in preparation for the scan; and in a fourth block 356, the scan can be performed while the subject is performing coached breathing.

[0061] FIG. 4 illustrates an example method 400 for generating and displaying the interactive visualization described above based on data generated by a secondary imaging device (e.g., secondary imaging device 105 of FIG. 1A ) of a medical imaging system that includes a guided breathing system, such as guided breathing system 208 of FIG. 2 . In the embodiment described in method 400, the secondary imaging device is a LiDAR light source / light emitter (e.g., a laser). However, it should be appreciated that other embodiments may use different remote sensing technologies. For example, a 3D camera may be used. The medical imaging system may be the non-limiting examples of CT imaging system 100 of FIG. 1A and / or medical CT imaging system 200 of FIG. 2 , or the medical imaging system may be a different type of imaging system including a gantry, table, and other components described herein. Method 400 and other methods described herein may be executed by a processor of the medical imaging system based on instructions stored in a memory of the medical imaging system. For example, the processor and memory may be included in a processing unit of the medical imaging system, such as position data processing unit 242 of FIG. 2 .

[0062] Method 400 begins at block 402, where the method includes scanning a subject using a LiDAR light source. During the scan, the LiDAR light source emits laser light toward the subject. The laser light reflects off the surface of the subject's body and the surrounding area of ​​the table or couch on which the subject is positioned and is detected by a receiver. The time of flight (TOF) of the reflected light is measured and used to determine the distance between the LiDAR light source and multiple points on the surface of the subject's body. These distance measurements are used to create a 3D virtual representation of the body's surface contour based on the multiple points.

[0063] At block 404, the method 400 includes acquiring, processing, and segmenting the LiDAR data. The surface contour points are generated as a collection of three-dimensional points, referred to herein as a point cloud. However, the point cloud may also include portions of the table or couch that may be detected by the LiDAR light source. A segmentation process can be performed to identify points in the point cloud that represent the surface contour of the subject's body from points in the point cloud that represent one or more surfaces of the table or couch (or other components of or disposed within the medical imaging system). The segmentation process can use various techniques and methods known in the art. In one embodiment, the acquired LiDAR data is segmented using density-based spatial clustering of noise-inclusive objects (DBSCAN).

[0064] At block 406, the method 400 includes determining an initial surface of interest (SOI) for the segmented 3D region and presenting the SOI on a display device of the guided breathing system (e.g., patient display device 130 of FIG. 1A or display device 162 of FIG. 1C) in the segmented 3D region. In some embodiments, the SOI may alternatively be presented on a display device of the medical imaging system (e.g., display device 232 of FIG. 2). The initial SOI may be selected based on a scanning protocol selected for scanning the subject with the medical imaging system. For example, the scanning protocol may indicate that the ROI of the scan is located in the subject's abdomen. As a result of the scanning protocol indicating that the ROI is located in the abdomen, the SOI may be presented in the segmented 3D region via a visual indicator, such as a guide line defining the initial SOI, superimposed on the segmented 3D region.

[0065] 8A , a segmented 3D point cloud 800 of the surface of a subject's chest is shown, where the segmented 3D point cloud 800 may be generated from a LiDAR light source as described with respect to FIG. 4 and displayed on a display screen. An SOI 802 is indicated in the segmented 3D point cloud 800 by a first index line 804 and a second index line 806, and the SOI 802 includes points of the segmented 3D point cloud 800 that lie between the first index line 804 and the second index line 806. Specifically, the SOI 802 may be defined as points of the segmented 3D point cloud 800 that lie between a first boundary plane 814 in the y dimension (shown on the reference coordinate axis 801) defined by the first index line 804 and a second boundary plane 816 in the y dimension defined by the second index line 806.

[0066] The size (e.g., surface area) and / or position of the SOI 802 in the segmented 3D point cloud 800 can be adjusted by adjusting the position of one or both of the first and second index lines 804 and 806 (and corresponding bounding planes 814 and 816) in the first direction 810 or the second direction 811 in the segmented 3D point cloud 800. For example, the size of the SOI 802 can be increased by adjusting the position of the first index line 804 in the first direction 810 and the position of the second index line 806 in the second direction 811, or the size of the SOI 802 can be decreased by adjusting the position of the first index line 804 in the second direction 811 and the position of the second index line 806 in the first direction 810. Additionally or alternatively, the relative position of the SOI 802 in the segmented 3D point cloud 800 can be adjusted by adjusting both the position of the first index line 804 and the position of the second index line 806 in a first direction 810, or by adjusting both the position of the first index line 804 and the position of the second index line 806 in a second direction 811. By adjusting the position of the first index line 804 and the position of the second index line 806, a user of the coached breathing system (e.g., an operator, technician, or caregiver of a medical imaging system instructing a subject on coached breathing) can indicate to the coached breathing system a set of points to be selected from the segmented 3D point cloud 800 and used to model the subject's breathing in real time during coached breathing training.

[0067] Although SOI 802 is described herein as being defined by labeled lines 804 and 806, it should be appreciated that in other embodiments, SOI 802 may be represented differently without departing from the scope of this disclosure.

[0068] Returning to method 400, at block 407, the method includes determining whether the initial SOI has been accepted by the user. In various embodiments, the display device is a touch screen, and the user can select a control element on the display device to accept the initial SOI. Alternatively, the user can select a control on a user input device of the coached breathing system (e.g., operator console 220 of FIG. 2).

[0069] If the initial SOI is not accepted at block 407, method 400 proceeds to block 408. At block 408, method 400 includes modifying the initial SOI based on input received from a user. For example, the input received from the user may include an adjusted position of a landmark line that is superimposed on the segmented 3D point cloud, as described above.

[0070] Once the initial SOI is accepted in 407, or once the initial SOI is modified in block 408, the method proceeds to block 410. In block 410, the method includes selecting a portion of the segmented 3D point cloud corresponding to the accepted SOI (e.g., a second, smaller point cloud separated from the segmented 3D point cloud). The separated point cloud can be used to display a virtual morphological representation of the target area of ​​the subject's body on a display device. The separated point cloud may be a set of points contained within the accepted SOI, in which case selecting the separated point cloud includes determining a set of points in the segmented 3D point cloud of the subject's chest that are located between a first plane defined by a first reference line of the accepted SOI and a second plane defined by a second reference line of the accepted SOI (e.g., boundary plane 814 and boundary plane 816).

[0071] 8B illustrates a separated point cloud 850 that may be selected from the segmented 3D point cloud 800 of FIG. 8A based on the SOI 802. The separated point cloud 850 may include points of the 3D point cloud 800 that are between the first bounding plane 814 and the second bounding plane 816. In other words, the separated point cloud 850 may include points of the 3D point cloud 800 that have Z coordinates that are between the first Z coordinate of the first bounding plane 814 and the second Z coordinate of the second bounding plane 816.

[0072] Returning to method 400, a virtual morphological representation of a target portion of the subject's body (e.g., a portion of the subject's chest) can be displayed on a display device such that the virtual morphological representation adjusts in real time as the subject breathes. For example, as the subject inhales, the subject may see the virtual morphological representation expand on the display device, and as the subject exhales, the subject may see the virtual morphological representation contract on the display device.

[0073] Referring to Figure 9, an exemplary respiratory visualization 900 is shown, in which the respiratory visualization 900 may be displayed on a screen 903 of a display device 902 of a coached breathing system, such as coached breathing system 208 of Figure 2. The display device 902 may be a non-limiting example of the patient display device 130 of Figure 1A, the head-mounted display 180 of Figure 1B, and / or the display device 162 of Figure 1C. The respiratory visualization 900 may be displayed to a subject in a medical imaging system during coached breathing training, as described above.

[0074] The respiratory visualization 900 includes a visual representation 906 of the subject's chest and a virtual morphological representation 904 of a portion of the subject's chest. The visual representation 906 may be generated from a segmented 3D point cloud, such as the segmented 3D point cloud 800 of FIG. 8A . The virtual morphological representation 904 may be generated from the SOI of the segmented 3D point cloud. During training with the guided breathing system, the virtual morphological representation 904 may be updated in real time to show the movement of the subject's chest. For example, as the subject inhales, the virtual morphological representation 904 may expand and become larger, and as the subject exhales, the virtual morphological representation 904 may contract and become smaller. In other words, the virtual morphological representation 904 may allow the subject to visualize the movement of their chest on the screen 903 while breathing.

[0075] The breathing visualization 900 includes a set of breathing instructions 910 that are displayed on the screen 903. The breathing instructions 910 can indicate to the subject when to inhale. In the illustrated embodiment, an "inhale" instruction can be displayed on the screen 903 when the subject is instructed to inhale and not displayed on the screen 903 when the subject is not instructed to inhale. Alternatively, the "inhale" instruction can be displayed on the screen 903 and illuminated or lit when the subject is instructed to inhale, and not illuminated or lit when the subject is not instructed to inhale. Similarly, an "exhale" instruction can be displayed or illuminated on the screen 903 when the subject is instructed to exhale, and not displayed or lit when the subject is not instructed to exhale. For example, a "hold your breath" instruction may be displayed or highlighted on screen 903 at times when the subject is instructed to hold their breath between inhalations and exhalations, and may not be displayed or highlighted on screen 903 when the subject is not instructed to hold their breath. In this manner, a set of instructions 910 may instruct the subject to follow a breathing pattern during various breathing cycles, where each breathing cycle includes one inhalation and one exhalation.

[0076] The breathing visualization 900 may include a timeline 908 that may display the progress of the coached breathing over a predetermined duration of the coached breathing. During training, a marker 909 may indicate the current time within the predetermined duration. For example, at the beginning of the predetermined duration, the marker 909 may be located at a first end 920 of the timeline 908. As time progresses along the predetermined duration, the marker 909 may move correspondingly until it reaches a second end 921 of the timeline 908. In various embodiments, the predetermined duration of the coached breathing may include a first inspiratory phase of the coached breathing and a second expiratory phase of the coached breathing, as described in further detail below.

[0077] Additionally, in the illustrated embodiment, the timeline 908 is divided into four segments. The first segment 912 and the second segment 914 may correspond to a first stage of coached breathing, during which the range of motion of the subject's chest is measured relative to a first set of reference points associated with an expanded chest. Specifically, the first segment 912 may correspond to a time during which the subject is instructed to inhale. Between the first segment 912 and the second segment 914, the subject is instructed to hold their breath after inhalation, and the first set of reference points is generated during the breath hold. The second segment 914 may correspond to a time during which the movement of the subject's chest is monitored. The third segment 916 and the fourth segment 918 may correspond to a second stage of coached breathing, during which the range of motion of the subject's chest is measured relative to a second set of reference points associated with a contracted chest. Specifically, the third segment 916 may correspond to a time during which the subject is instructed to exhale. Between the third section 916 and the fourth section 918, the subject can be instructed to hold their breath after exhaling, and a second set of reference points is generated during the breath hold. The fourth section 918 can correspond to a time during which movement of the subject's chest is monitored.

[0078] Each of the first segment 912, the second segment 914, the third segment 916, and the fourth segment 918 may be visually distinguishable from one another, for example, via color coding or shading. For example, the first segment 912 may have a first color or shading, the second segment 914 may have a second color or shading, the third segment 916 may have a third color or shading, and the fourth segment 918 may have a fourth color or shading (or may have a color coding or shading similar to that of the second segment 914). In this manner, the subject can visually determine where they are in the respiratory cycle during exercise and determine how much time is remaining until the subsequent segment of the respiratory cycle. At the end of the respiratory cycle, the indicator 909 may move from the second end 921 back to the first end 920 to begin the next cycle.

[0079] The subject can follow instructions during the training. While following the instructions, the subject can view the virtual morphology representation 904. Viewing the virtual morphology representation 904 while breathing can help the subject replicate or follow a target or selected breathing pattern, where the selected breathing pattern can reduce chest movement.

[0080] Furthermore, in some embodiments, a 3D coached breathing model may be generated and displayed on the screen 903 along with the virtual morphological representation 904, where the 3D coached breathing model may be a target 3D virtual representation of a portion of the surface of the subject's chest that moves in real time as the subject breathes. In this manner, the target 3D virtual representation may model a desired motion of the subject's chest. For example, the coached breathing model may be aligned with and / or superimposed on the virtual morphological representation 904. The coached breathing model may indicate to the subject specific desired positions of the portion of the surface of the chest at various times during a respiratory cycle, such that the subject may adjust their breathing to match a first position of the virtual morphological representation 904 with a second position of the coached breathing model.

[0081] Because the instructed breathing model is generated based on acquired LiDAR / 3D camera data, an advantage of using the instructed breathing model is that it can individually indicate how a particular subject's chest should move during breathing. For example, during breathing, not all points on the chest rise and fall or move simultaneously in the same direction. Some breathing patterns involve breathing from the diaphragm, while others involve breathing using the pectoral muscles. By attempting to match the instructed breathing model to the virtual morphological representation 904, the subject can achieve the selected breathing pattern more quickly and efficiently. Additionally, the instructed breathing model may "gamify" the task of achieving the selected breathing pattern, making the visual challenge of matching the instructed breathing model to the virtual morphological representation 904 easier, more enjoyable, and / or more engaging than following breathing instructions 910. The generation of the instructed breathing model is described below with reference to FIG. 5A.

[0082] 4, in block 412, method 400 includes training the subject for self-calibration of their breathing pattern with on-screen training instructions (e.g., breathing instructions 910) and a virtual morphological representation of a portion of the surface of the subject's chest (e.g., virtual morphological representation 904). Training the subject for self-calibration of their breathing pattern is described in further detail below with respect to FIG. 5A.

[0083] At block 414, the method 400 includes performing a scan with the medical imaging system to acquire image data while the subject is performing a breathing pattern, which is described in further detail below with respect to FIG.

[0084] At block 416, the method 400 includes reconstructing an image from the acquired image data and displaying the image on a display device (e.g., display device 232 of FIG. 2) of the medical imaging system. Alternatively, the image may be stored in memory (e.g., mass storage device 218) of the medical imaging system. As a result of the subject performing the guided breathing, the reconstructed image may be of higher quality than if the subject did not follow the selected breathing pattern.

[0085] Turning now to FIGURE 5A, an example method 500 for training a subject of a medical imaging system in guided breathing via a visual display including on-screen training instructions prior to performing a scan is shown. As previously described, the visual display may include an interactive visualization of a portion of the surface of the subject's chest to assist the subject in achieving a selected breathing pattern. The visual display may be displayed on a screen of a display device of the guided breathing system, such as display device 130 of FIGURE 1A and / or display device 162 of FIGURE 1C.

[0086] Method 500 begins at block 502, where the method includes displaying instructions to a subject to perform coached breathing and monitoring the coached breathing for a predetermined duration. For example, the predetermined duration may be 5 minutes for a child or 10 minutes for an adult. In various embodiments, the coached breathing includes a first phase and a second phase. In the first phase, movement of the subject's chest is monitored and measured relative to a first set of 3D points (e.g., a first set of reference points) on a surface of the subject's chest, where the first set of reference points corresponds to a position of the subject's chest in an expanded state after inspiration. In the second phase, movement of the subject's chest is monitored and measured relative to a second set of 3D points (e.g., a second set of reference points) on a surface of the subject's chest, where the second set of reference points corresponds to a position of the subject's chest in a deflated state after expiration.

[0087] In block 504, displaying instructions and monitoring coached breathing includes setting the state of the coached breathing system to an inspiration state. Once the inspiration state is set, the inspiration phase of the coached breathing can begin. During the inspiration phase, the range of motion of the subject's chest during inspiration can be measured relative to the expanded chest to determine whether the range of motion of the subject's chest exceeds a threshold range of motion. Instructions for the subject to inhale can be displayed on the screen. For example, as described above with respect to FIG. 9 , written instructions to inhale for the duration of the inspiration can be displayed or illuminated on the screen. Additionally, the inspiration state can be indicated on a timeline line (e.g., timeline line 908) displayed on the screen via, for example, lighting or highlighting a portion of the timeline line corresponding to the desired inspiration duration, an arrow (e.g., indicator 909) indicating the current time relative to the timeline line, or another visual indicator. For example, the desired inspiration duration can be five seconds. After inhaling, instructions can be displayed on the screen for the subject to hold their breath for a first predetermined duration. For example, the first predetermined duration may be 10 seconds.

[0088] In block 506, performing the supervised breathing cycle includes registering a first cloud of reference points based on the LiDAR data while the subject is holding a breath, where the first cloud of reference points is a collection of 3D points on the surface of the subject's chest (and / or abdomen). Registering the first cloud of reference points based on the LiDAR data is described in more detail with respect to FIG. 6.

[0089] 6 illustrates a method 600 for registering a point cloud corresponding to the surface of a subject's chest in a medical imaging examination based on LiDAR data. Method 600 may be performed within a guided breathing system of a medical imaging system as part of a method for implementing guided breathing, such as method 500 of FIG. 5A.

[0090] At block 602, method 600 includes acquiring a first set of LiDAR data. The LiDAR data may be acquired via a LiDAR imager of a guided breathing system, such as secondary imager 105 and / or secondary imager 164. In various embodiments, the secondary imager may be integrated into a medical imaging system, such as CT imaging system 100.

[0091] At block 604, method 600 includes creating a point cloud from the acquired LiDAR data. The point cloud may include a plurality of points detected by the LiDAR imager on the surface of the subject's chest. At block 606, method 600 includes performing a segmentation process to eliminate points detected by the LiDAR imager that are not on the surface of the chest (e.g., points on the surface of a table or couch on which the subject is positioned, such as table 114 and / or table 173 in FIGS. 1A and 1C, respectively).

[0092] At block 608, the method 600 includes isolating the point cloud data for an SOI of the segmented point cloud. In various embodiments, the SOI may be indicated by an operator of the coached breathing system via an input device of the coached breathing system, such as the operator console 220 of FIG. 2. The operator may indicate the SOI by adjusting a marker line in the visualization of the segmented point cloud described with reference to FIG. 8A. After the operator indicates the SOI, the coached breathing system may determine a set of points in the segmented point cloud that lie within the marker line.

[0093] At block 610, method 600 includes transforming the separated point cloud corresponding to the SOI into 3D coordinates for display on a display device of the coached breathing system (e.g., display device 130 and / or display device 162). The 3D coordinates may be stored and used as a reference to generate an interactive visualization of the subject's chest while the subject is performing coached breathing, as described above with respect to FIG. 5A.

[0094] Returning to FIG. 5A , in block 508, displaying instructions and monitoring guided breathing includes measuring the subject's chest movement relative to the first set of reference points. Instructions may be displayed on a screen to instruct the subject to breathe according to a predetermined breathing pattern. For example, as described above with respect to FIG. 9 , written instructions to inhale may be displayed or illuminated on the screen for the duration of a desired inspiration, and written instructions to exhale may be displayed or illuminated on the screen for the duration of a desired expiration, according to the predetermined breathing pattern. Additionally, for some breathing patterns, the subject may be instructed to hold their breath. The subject's chest movement during inspiration may be measured while the subject breathes according to the predetermined breathing pattern. Measuring the subject's chest movement is described in more detail below with respect to FIG. 5B .

[0095] 5B, method 550 illustrates a procedure for measuring chest movement of a subject during coached breathing in coached breathing system 208. In various embodiments, method 550 may be performed as part of method 500 described above. It should be appreciated that each step of method 550 may be repeated iteratively multiple times until a predetermined duration is reached. For example, the predetermined duration may correspond to the length of the inspiration phase of coached breathing or the expiration phase of coached breathing. In various embodiments, method 550 may be performed at regular intervals, such as every millisecond.

[0096] Method 550 begins at block 551, where method 550 includes receiving a cloud of reference points. The cloud of reference points may be a cloud of points corresponding to the surface of a subject's chest at an initial time point, for which other clouds of points corresponding to the surface of the subject's chest are measured during guided breathing. For example, the cloud of reference points may correspond to the surface of the subject's chest when the chest is in an expanded state after inspiration (e.g., the first cloud of reference points in FIG. 5A ), or may correspond to the surface of the subject's chest when the chest is in a contracted state after expiration (e.g., the second cloud of reference points in FIG. 5A ).

[0097] At block 552, the method 550 includes generating a point cloud corresponding to the surface of the subject's chest while the subject is breathing (e.g., according to a breathing pattern). In various embodiments, the point cloud may be generated by following one or more steps of FIG. 6 as described above with respect to generating the first reference point cloud. The SOI used to generate the point cloud may be the same as the SOI selected by the operator for the first reference point cloud.

[0098] At block 554, method 550 includes calculating a distance metric between points in the reference point cloud and points in the generated point cloud at each equal interval t when the point clouds of the subject's chest were generated to estimate the range of chest motion during breathing. In various embodiments, the distance metric may be based on the Euclidean distance between each point in the first point cloud and a corresponding point in the second point cloud. For example, the distance metric may be the average Euclidean distance for each pair of points.

[0099] In some embodiments, the distance metric may be a weighted average Euclidean distance, in which certain portions of the first and second clouds of points are weighted more heavily than other portions of the first and second clouds of points. For example, the weighting of the distance metric may depend on the breathing pattern the subject is instructed to match. The first breathing pattern may involve pulmonary breathing, in which case the subject is instructed to move portions of each of the first and second clouds of points corresponding to the upper part of the chest to a greater extent than portions of the first and second clouds of points corresponding to the lower part of the chest when breathing. The second breathing pattern may involve diaphragmatic breathing, in which case the subject is instructed to move portions of each of the first and second clouds of points corresponding to the lower part of the chest to a greater extent than portions of the first and second clouds of points corresponding to the upper part of the chest when breathing. If the subject is trained to conform to a first respiratory pattern, the Euclidean distance between points in the first cloud of points and points in the second cloud of points corresponding to an upper part of the chest may be weighted more heavily than the Euclidean distance between points in the first cloud of points and points in the second cloud of points corresponding to a lower part of the chest. Alternatively, if the subject is trained to conform to a second respiratory pattern, the Euclidean distance between points in the first cloud of points and points in the second cloud of points corresponding to a lower part of the chest may be weighted more heavily than the Euclidean distance between points in the first cloud of points and points in the second cloud of points corresponding to an upper part of the chest. In this manner, an estimated range of motion of the subject's chest may be defined based on the selected respiratory pattern.

[0100] At block 556, the method 500 includes determining whether the estimated range of motion of the chest exceeds a threshold range of motion. If the estimated range of motion exceeds the threshold range of motion, it can be inferred that the expansion of the subject's chest exceeds the desired parameters of the respiratory pattern and the subject is not breathing according to the selected respiratory pattern.

[0101] 10, a respiration graph 1000 shows two plots, a first plot 1002 showing a first exemplary breathing pattern of a subject and a second plot 1004 showing a second exemplary breathing pattern of the subject. Time is shown on the x-axis of respiration graph 1000, and a pass / fail assessment of the range of motion of the subject's chest during breathing is shown on the y-axis of respiration graph 1000. Expansion of the subject's chest during inspiration is indicated by an upward peak (e.g., in direction 1030), and contraction of the subject's chest during expiration is indicated by a downward peak (e.g., in direction 1032).

[0102] The first exemplary breathing pattern is a shallow breathing pattern and includes a first inspiration 1003, an expiration 1005, and a second inspiration 1007. The range of motion of the subject's chest during the first exemplary breathing pattern may be defined by a distance 1020 between a maximum expansion of the subject's chest during the first inspiration 1003 at point 1040 and a minimum contraction of the subject's chest during expiration 1005 at point 1042. Distance 1020 may be less than a threshold range of motion, such that the range of motion of the subject's chest during the first exemplary breathing pattern is acceptable.

[0103] In contrast, the second exemplary breathing pattern is a deeper breathing pattern and includes a first inspiration 1010 and an expiration 1012. The range of motion of the subject's chest during the second exemplary breathing pattern may be defined by a distance 1022 between the maximum expansion of the subject's chest during the first inspiration 1010 at point 1011 and the minimum contraction of the subject's chest during expiration 1012 at point 1013. Distance 1022 may be greater than the threshold range of motion, such that the range of motion of the subject's chest during the first exemplary breathing pattern is considered to be acceptable but excessive.

[0104] Returning to method 550, if in block 556 it is determined that the estimated range of motion exceeds the threshold range of motion, method 500 proceeds to block 558. In block 558, method 550 includes notifying the subject that their breathing is not adhering to the selected breathing pattern, and method 550 returns to block 552 to continue measuring the subject's chest motion at the next equal interval t.

[0105] In some embodiments, the subject can be notified on a display of the coached breathing system. For example, a visual indicator that the subject is not adhering to a breathing pattern may be displayed on the display in the form of written or graphical elements, or by lighting up, brightening, or displaying existing elements of the display in a different color. Additionally or alternatively, the subject may be notified via an indicator light located in the subject's environment (e.g., a light or illuminated portion on the inner surface 120, edge 121, and / or front surface 122 of the gantry 102 in FIG. 1A or the LED light 172 in FIG. 1C ), via an audio notification (e.g., a voice or audio recording) played through a speaker in the coached breathing system and / or in the subject's environment, via tactile feedback (e.g., vibration), or via a different manner.

[0106] If it is determined in block 556 that the estimated range of motion does not exceed the threshold range of motion, then the subject can be assumed to be adhering to the selected breathing pattern and method 550 proceeds to block 560 .

[0107] At block 560, the method 500 includes determining whether a predetermined duration of coached breathing has been reached. The predetermined duration may correspond to a phase of coached breathing, such as an inspiration phase (where the subject's chest movement is measured relative to an expanded chest) or an expiration phase (where the subject's chest movement is measured relative to a contracted chest). For example, the predetermined duration may be 10 minutes.

[0108] If it is determined in block 560 that the predetermined duration has not been reached, then method 500 returns to block 552 and continues monitoring the range of motion of the subject's chest during the next equal interval t of guided breathing. Alternatively, if it is determined in block 560 that the predetermined duration has been reached, then method 550 ends.

[0109] Returning to FIG. 5A , in block 510, displaying instructions and monitoring coached breathing includes setting the state of the coached breathing system to an exhalation state. Once set to the exhalation state, the exhalation phase of the coached breathing can begin. Instructions can be displayed on the screen to instruct the subject to exhale. For example, as described above with respect to FIG. 9 , a written instruction to exhale can be displayed or illuminated on the screen for the duration of the exhalation. During the exhalation phase, the range of motion of the subject's chest can be measured with respect to a contracted chest to determine whether the range of motion of the subject's chest exceeds a threshold range of motion. The exhalation state can be indicated by a timeline displayed on the screen. The desired duration of the exhalation phase can be equal to the duration of the inhalation phase, or the desired duration of the exhalation phase can be different from the duration of the inhalation phase. After exhaling, instructions can be displayed on the screen to instruct the subject to hold their breath for a second predetermined duration, which can be equal to the first predetermined duration.

[0110] In block 512, displaying instructions and monitoring guided breathing includes registering a second set of reference points on the surface of the subject's chest (and / or abdomen) based on the LiDAR data while the subject holds their breath, as described above with respect to FIG. 6. In other words, the first set of reference points is registered at a first time when the subject's chest may be in an expanded position as a result of a previous inspiration. The second set of reference points is registered at a second, later time when the subject's chest may be in a contracted position as a result of a previous expiration. In this manner, the first set of reference points is referenced by a first set of 3D coordinates, and the second set of reference points is referenced by a second, different set of 3D coordinates.

[0111] In block 514, displaying instructions and monitoring coached breathing includes measuring the subject's chest movement relative to the second set of reference points. Instructions can be displayed on a screen to instruct the subject to breathe according to a predetermined breathing pattern. For example, as described above with reference to FIG. 9, a written instruction to inhale can be displayed or illuminated on the screen for the desired duration of inspiration, and a written instruction to exhale can be displayed or illuminated on the screen for the desired duration of expiration, according to the predetermined breathing pattern. Additionally, for some breathing patterns, the subject can be instructed to hold their breath. The subject's chest movement can be measured while the subject is breathing according to the predetermined breathing pattern. The subject's chest movement can be measured as described above with reference to FIG. 5B. Similar to the inspiration phase, if the subject's chest movement range is not within the threshold movement range, an indicator can be provided to the subject, for example, via an indicator light or on the display screen of the coached breathing system. After a predetermined duration of the expiratory phase, measuring the range of motion of the subject's chest may end, and method 500 proceeds to block 516. In block 516, method 500 includes determining whether the collective range of motion of the subject's chest during both the inspiratory and expiratory phases exceeds a threshold range of motion. For example, the collective range of motion may be an average of multiple measurements of the distance between the surface of the subject's chest and a set of reference points (e.g., either the first set of reference points or the second set of reference points). In some embodiments, the collective range of motion may be a weighted average of the multiple measurements. For example, a first average range of motion of the subject's chest during the inspiratory phase may be weighted more heavily than a second average range of motion of the subject's chest during the expiratory phase, or the first average range of motion of the subject's chest during the inspiratory phase may be weighted less heavily than a second average range of motion of the subject's chest during the expiratory phase.

[0112] If the collective range of motion of the subject's chest exceeds the threshold range of motion, method 500 proceeds to block 518. At block 518, method 500 may include continuing training the subject in supervised breathing, whereby method 500 returns to block 502. Alternatively, if the collective range of motion of the subject's chest does not exceed the threshold range of motion, method 500 proceeds to block 520. At block 520, method 500 includes indicating to the subject and / or an operator of the supervised breathing system that the subject has completed training in supervised breathing, and method 500 ends.

[0113] Referring now to FIG. 7 , an example method 700 for performing a medical imaging scan on a subject while the subject is performing supervised breathing is shown. The subject may have undergone a supervised breathing training session prior to the medical imaging scan, as described above with respect to FIG. 5A . In one embodiment, the subject is trained in supervised breathing in a first location, such as the training room shown in FIG. 1C . The subject may successfully complete the training, thereby demonstrating adherence to a selected breathing pattern for a predetermined duration. After completing the training, the subject may be placed on a table of an imaging system, such as the CT imaging system 100 of FIG. 1A , and positioned within the imaging system gantry. In some embodiments, the subject may be positioned on the table such that the subject can view an external display of the imaging system's supervised breathing system, such as display 130 of FIG. 1A . During acquisition of projection data during an examination, the subject can view coached breathing instructions on a display device, where the coached breathing instructions may include a 3D visualization of a portion of the subject's chest that moves in real time as the subject inhales and exhales. In addition, a 3D coached breathing model may be displayed adjacent to or superimposed on the 3D visualization, where the 3D coached breathing model can indicate a target position of the chest in real time so that the subject can adhere to a selected breathing pattern by matching the movement of the subject's chest indicated by the 3D visualization to the 3D coached breathing model. In other embodiments, the instructions, 3D visualization, and 3D coached breathing model may be displayed to the subject via a head-mounted display, such as head-mounted display 180 of FIG. 1B.

[0114] At block 702, the method 700 includes adjusting a medical imaging scan protocol based on a subject's breath-hold time. The breath-hold time may be the duration that the subject can consistently and reliably hold their breath between inspiration and expiration, and may be determined as a result of a training session on guided breathing. Different subjects may have different breath-hold times.

[0115] The protocol may be determined based on the type of medical imaging scan being performed and / or the region of interest of the subject being scanned. For example, an imaging system operator may select a protocol using an input device (e.g., display 232) of the imaging system, or the protocol may be automatically selected based on one or more parameters of the medical imaging scan established by the operator. In various embodiments, the protocol may include settings for breath-hold durations, which may vary from subject to subject. For example, a first subject may be able to consistently and reliably hold their breath for a first shorter duration, while a second subject may be able to consistently and reliably hold their breath for a second longer duration. The protocol may adjust between performing a first scan on a first subject and a second scan on a second subject to account for differences between the first and second durations. During a first scan, a first acquisition of projection data may depend on the first duration, and during a second scan, a second acquisition of projection data may depend on the second duration.

[0116] At block 704, the method 700 includes performing a medical imaging scan while the subject is performing coached breathing. As described above, during coached breathing, the subject can follow breathing instructions displayed on a display device using a visual representation of their chest region as a guide and / or by matching the visual representation with a 3D coached breathing model displayed on the display device.

[0117] At block 706, method 700 includes calculating a stability score for the subject based on the subject's performance of the coached breathing. The stability score may be a value generated by the coached breathing system that indicates the degree of stability of the subject's chest during breathing. For example, a high stability score may indicate that the subject was able to maintain the range of motion of their chest within a minimum threshold motion range with high accuracy and consistency. A low stability score may indicate that the subject was unable to maintain the range of motion of their chest within a minimum threshold motion range with high accuracy and consistency. For example, a low stability score may be the result of the subject feeling anxious and breathing faster and / or deeper. The quality of images reconstructed from projection data acquired during coached breathing may depend on the degree of stability of the subject's chest, such that images produced from a subject with a high stability score will be of higher quality than those produced from a subject with a low stability score.

[0118] In some embodiments, the stability score S may be calculated using the following formula: S=||PCC initial -max(|PCC scan duration |)|| (1) where PCC is the point cloud coordinate. In other words, the stability score may be based on the overall difference between a first set of point cloud coordinates corresponding to minimum chest expansion and a second set of point cloud coordinates corresponding to maximum chest expansion, as described above with respect to the inspiration phase, or may be based on the overall difference between a first set of point cloud coordinates corresponding to maximum chest expansion and a second set of point cloud coordinates corresponding to minimum chest expansion, as described above with respect to the expiration phase. In other embodiments, the stability score may be generated based on a different equation. For example, if the subject follows a breathing pattern based on relative movement of different parts of their chest and / or abdomen (e.g., upper thoracic breathing vs. diaphragmatic breathing), the stability score may be calculated based on the relative difference between portions of the first point cloud and corresponding portions of the second point cloud, where other portions of the first and second point clouds may not contribute to the stability score.

[0119] At block 708, the method 700 includes embedding the stability score in scan data acquired during the medical imaging scan. For example, the stability score may be included in metadata for the medical imaging scan, which may be stored with the projection data used for image reconstruction. In some embodiments, the metadata may also store separated point cloud data (e.g., a visual representation of a portion of the subject's chest) that may be generated by the guided breathing system and displayed on a display device.

[0120] At block 710, method 700 includes storing scan data acquired during the medical imaging scan in a memory of the imaging system. For example, the scan data may be stored in the memory of computing device 216 or mass storage 218 of FIG. 2. Including a stability score in the scan data allows a record of the subject's performance of guided breathing during the scan to be associated with the scan data, which may provide a preliminary indication of the quality of the image formed from the scan. The stability score may be stored by a quality inspection system associated with the image. Because the stability score may be correlated with image quality, the CT exam or scan may be stored with a stability score. In such cases, exams with high stability scores may be considered first, if preferred.

[0121] Additionally, the stability score can also be a searchable parameter. For example, a radiologist may want to selectively review historical images generated during a series of scans performed on a patient over time. The radiologist may want to view images that are above a threshold quality and not view images that are below the threshold quality. The radiologist can set a filter in the medical imaging system to search for images generated from scans of the patient that have a high embedded stability score. By viewing images with a high embedded stability score and avoiding images without a high embedded stability score, the radiologist can more quickly and efficiently find and review higher quality images compared to an alternative scenario in which stability scores are not embedded in the scan data.

[0122] Thus, disclosed herein is a coached breathing system for a medical imaging system that, in contrast to other coached breathing systems, displays a 3D visualization of a selected portion of a subject's chest on a display device along with breathing instructions while the subject practices or performs coached breathing, where the selected portion can be adjusted to include a smaller surface area of ​​the chest (e.g., a reduced point set on the subject's chest) than the entire surface of the chest (e.g., covering the subject's entire torso). The smaller surface area can be selected by the operator to cover a specific portion of the chest that expands and contracts during a particular breathing pattern. For example, a first breathing pattern can involve moving an upper portion of the chest associated with the subject's lungs, and a second breathing pattern can involve moving a lower portion of the chest associated with the subject's diaphragm. For example, a first scan can be performed on the subject's abdomen, and a second scan can be performed on the subject's lungs. The quality of the first scan can depend on the subject following the first breathing pattern, and the quality of the second scan can depend on the subject following the second breathing pattern. For example, a first breathing pattern may involve expanding the chest muscles to breathe while keeping the abdomen still, and a second breathing pattern may involve expanding the subject's diaphragm to breathe while keeping the chest still.

[0123] In this manner, during coached breathing, the operator can display only the portions of the chest involved in a particular breathing pattern and not the portions of the chest not involved in the particular breathing pattern. Displaying selected portions, as opposed to alternative 3D visualizations that include a larger surface area, can reduce the amount of memory and / or processing resources used by the coached breathing system and / or medical imaging system to generate the 3D visualization, thereby enhancing the performance and operation of the coached breathing system and / or medical imaging system. As a result of the reduction in the amount of memory and / or processing resources used to generate the 3D visualization, a greater amount of resources can be made available for other medical imaging and / or other tasks. Additionally, the subject's performance with coached breathing can be enhanced, resulting in less movement of the subject's chest during medical imaging, resulting in higher quality reconstructed images. As a result of the higher quality reconstructed images, the subject's evaluation and / or diagnosis can be more accurate.

[0124] Furthermore, a 3D coached breathing model can be generated based on the 3D visualization and displayed simultaneously with the 3D visualization (e.g., superimposed on the 3D visualization), where the 3D coached breathing model can be a target 3D representation of a selected portion that moves in real time as the subject breathes. The target 3D virtual representation can model a target motion of the subject's chest. The 3D coached breathing model can show the subject how to adjust their breathing with respect to the 3D coached breathing model to achieve a selected breathing pattern, where the 3D coached breathing model can show the subject in real time the shape of the modified 3D visualization that is personalized based on the subject's breathing. Displaying the 3D coached breathing model together with the 3D visualization of the subject's breathing can help the subject adopt the selected breathing pattern more quickly, reducing the amount of time the subject spends performing coached breathing. Reducing the amount of time spent by the subject performing coached breathing can reduce the amount of memory and / or processing resources used by the coached breathing system and / or medical imaging system to generate the 3D visualization and 3D coached breathing model, improving the performance and operation of the coached breathing system and / or medical imaging system, freeing up resources for other tasks, and improving the quality of the resulting reconstructed images. Additionally, generating a 3D coached breathing model based on 3D visualization, rather than generating the 3D coached breathing model from scratch without relying on 3D visualization, can more efficiently utilize and / or reduce the computational and memory resources of the coached breathing system and / or medical imaging system.

[0125] The present disclosure also relates to a method for a medical imaging system, the method including: generating a three-dimensional (3D) virtual representation of a portion of a chest surface of a subject of the medical imaging system via a sensor system of the medical imaging system that acquires data of the surface, the portion being dimensionally adjustable by an operator of the medical imaging system; displaying changes in the 3D virtual representation in real time on a display device of the medical imaging system to the subject while the subject is breathing; displaying instructions on the display device to the subject to perform coached breathing according to a selected breathing pattern; and indicating the deviation to the subject in response to detecting a deviation of the subject's breathing pattern from the selected breathing pattern. In a first example of the method, displaying instructions to perform coached breathing according to the selected breathing pattern further includes displaying instructions indicating when to start inhalation, when to start exhalation, and when to hold a breath, and displaying time series lines indicating the duration of inhalation, the duration of exhalation, and the duration of the subject's breath hold. In a second example of the method, optionally including the first example, indicating the displacement to the subject as a result of detecting the displacement further includes, in response to determining that the displacement exceeds a displacement threshold, performing at least one of: displaying an indication of the displacement on a display device, illuminating a light or visual indicator included in an environment of the CT imaging system, illuminating a light or visual indicator in the medical imaging system, providing tactile feedback (e.g., a vibration) to the subject, and providing an audio notification of the displacement. In a third example of the method, optionally including one or both of the first and second examples, determining that the displacement exceeds a displacement threshold further includes generating a first point cloud associated with a portion of the surface of the chest while the subject is holding their breath after inspiration, generating a second point cloud associated with the portion of the chest while the subject is holding their breath after expiration, calculating a Euclidean distance between the first point cloud and the second point cloud, and determining whether the Euclidean distance exceeds a distance threshold.In a fourth example of the method, optionally including one or more of the first through third examples, generating either the first point cloud or the second point cloud further includes acquiring data of the surface of the chest via one of a LiDAR system and a 3D camera, creating a 3D point cloud based on the data, isolating a portion of the 3D point cloud associated with the portion of the surface, and measuring 3D coordinates of the isolated portion. In a fifth example of the method, optionally including one or more of the first through fourth examples, the portion of the surface of the chest is defined by an operator of the medical imaging system based on a scanning protocol and a position of a visual element adjusted by the operator in visualizing the 3D point cloud. In a sixth example of the method, optionally including one or more of the first through fifth examples, one of the LiDAR system and the 3D camera is included in the medical imaging system, and the data is acquired while the subject is resting on a table of the medical imaging system. In a seventh example of the method optionally including one or more of the first through sixth examples, one of the LiDAR system and the 3D camera is included in a guided breathing exercise room, and the data is acquired while the subject is preparing for scanning in the guided breathing exercise room. In an eighth example of the method optionally including one or more of the first through seventh examples, displaying instructions to perform guided breathing according to the selected breathing pattern further includes displaying a breathing guide model generated based on the 3D virtual representation for the subject to follow, the breathing guide model indicating a target movement of a customized modified shape of the 3D virtual representation superimposed on the 3D virtual representation while the subject is breathing. In a ninth example of the method optionally including one or more or each of the first through eighth examples, displaying the respiratory guide model further includes: during a first respiratory cycle including one inspiration and one expiration, storing a 3D virtual representation of a portion of a surface of the chest for each time increment of a plurality of time increments over the first respiratory cycle, and applying a transformation function to each 3D point of each stored 3D virtual representation to generate a target 3D virtual representation for each time increment; and during each subsequent respiratory cycle, displaying each target 3D virtual representation for each time increment over the subsequent respiratory cycle.In a tenth example of the method, optionally including one or more of the first through ninth examples, displaying the respiratory guide model further includes displaying a target 3D virtual representation for each time increment of a plurality of time increments over each respiratory cycle, the respiratory cycle including one inspiration and one expiration, the target 3D virtual representation being based on a distance between each point in the first point cloud and a corresponding point in the second point cloud and an elapsed time of the respiratory cycle. In an eleventh example of the method, optionally including one or more of the first through tenth examples, the modality of the medical imaging system includes computed tomography (CT), magnetic resonance imaging (MR), positron emission tomography (PET), and nuclear medicine (NM) imaging. In a twelfth example of the method, optionally including one or more of the first through eleventh examples, the selected respiratory pattern is selected by an operator from a plurality of respiratory patterns based on a scanning protocol, an anatomical location of the subject, and / or a characteristic of the subject. In a thirteenth example of the method, optionally including one or more or each of the first through twelfth examples, the method further includes generating a stability score for the subject based on stability of the subject's chest during the subject's performance of the guided breathing during the medical imaging scan, and storing the stability score in the scan data acquired during the medical imaging scan.

[0126] The present disclosure also relates to a medical imaging system, the medical imaging system including an X-ray controller including one or more processors, the processor having executable instructions stored in a non-transitory memory of the medical imaging system that, when executed, cause the one or more processors to generate a three-dimensional (3D) virtual representation of a portion of a surface of a chest of a subject of the medical imaging system, the portion being dimensionally adjustable by an operator of the medical imaging system, displaying changes in the 3D virtual representation in real time to the subject on a display device of the medical imaging system while the subject is performing supervised breathing, displaying instructions to the subject on the display device to perform supervised breathing in accordance with a selected breathing pattern using the 3D virtual representation as a guide, and, in response to detecting a deviation in the subject's breathing pattern from the selected breathing pattern, indicating the deviation to the subject. In a first example of the system, detecting a deviation of the subject's respiratory pattern from the selected respiratory pattern further includes, while the subject is holding their breath after inhalation, creating a first 3D point cloud from data of the surface of the chest acquired via one of the LiDAR system and the 3D camera, isolating a first portion of the first 3D point cloud associated with the surface portion, and measuring 3D coordinates of the separated first portion to generate a first point cloud associated with the surface portion of the chest; while the subject is holding their breath after exhalation, creating a second 3D point cloud from data of the surface of the chest acquired via one of the LiDAR system and the 3D camera, isolating a second portion of the second 3D point cloud associated with the surface portion, and measuring 3D coordinates of the separated second portion to generate a second point cloud associated with the chest portion; calculating a Euclidean distance between the first point cloud and the second point cloud; and determining whether the Euclidean distance exceeds a distance threshold. In a second example of the system, which optionally includes the first example, one of the LiDAR system and the 3D camera is included in a supervised breathing exercise room, and data of the chest surface is acquired while the subject is preparing for the scan in the supervised breathing exercise room.In a third example of the system, optionally including one or both of the first and second examples, further instructions are stored in the non-transitory memory of the medical imaging system, which instructions, when executed, cause the one or more processors to display a respiratory guide model generated based on the 3D virtual representation for the subject to follow during supervised breathing, the respiratory guide model indicating a target motion of an individualized modified shape of the 3D virtual representation superimposed on the 3D virtual representation while the subject is breathing, the target motion including displaying the target 3D virtual representation at each time increment of a plurality of time increments over each respiratory cycle of the supervised breathing, the respiratory cycle including one inspiration and one expiration, and the target 3D virtual representation based on the distance between each point of the first point cloud and a corresponding point of the second point cloud and the elapsed time of the respiratory cycle. In a fourth example of a system optionally including one or more or each of the first through third examples, further instructions are stored in the non-transitory memory of the medical imaging system that, when executed, cause the one or more processors to generate a stability score for the subject based on the stability of the subject's chest during performance of guided breathing during the medical imaging scan, and store the stability score in scan data acquired during the medical imaging scan.

[0127] The present disclosure also relates to a method that includes, at a first point in time, acquiring scan data during a medical imaging scan of a subject via a medical imaging system while the subject is performing supervised breathing, generating a stability score for the medical imaging scan based on stability of the subject's chest during the subject's performance of supervised breathing, and storing the stability score in the scan data acquired for the medical imaging scan, and, at a second, later point in time, retrieving the scan data from a storage unit of the medical imaging system based on a filter setting for the stability score of the medical imaging system.

[0128] When describing elements of various embodiments of the present disclosure, terms such as "the," "said," "the," and "said" are intended to mean the presence of one or more of the element. Terms such as "first," "second," and "second" do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Furthermore, the terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements. When terms such as "connected" and "coupled" are used herein, they refer to the ability of one object (e.g., materials, elements, structures, members, etc.) to be connected or coupled to another object, whether the object is directly connected or coupled to the other object or whether one or more intervening objects exist between the two objects. Additionally, references to "one embodiment" or "an embodiment" in this disclosure should not be construed as excluding the existence of additional embodiments that also incorporate the recited features.

[0129] In addition to any modifications set forth above, many other variations and alternative arrangements can be devised by those skilled in the art without departing from the spirit and scope of the present description, and it is intended that the appended claims cover such modifications and arrangements. Thus, while the information has been described above with specificity and detail in connection with what is presently considered to be the most practical and preferred aspects, it will be apparent to those skilled in the art that many modifications, including but not limited to form, function, modes of operation, and usage, can be made without departing from the principles and concepts described herein. Moreover, the examples and embodiments, as used herein, are in all respects illustrative only and should not be construed as limiting in any manner. [Explanation of symbols]

[0130] 100 Computed Tomography (CT) Imaging System 102 Gantry 104 X-ray source 105 Secondary imaging device 106 X-ray radiation beam 108 detector array 112 Subject 114 Tables 120 Inside 121 Edge 122 Front 130 Patient display device 132 Movable Arm 134, 136, 138 Rotation direction of movable arm 140 First Position 141 Second Position Alternative Configurations of the 100 CT Imaging System 150 160 Second Type of Guided Breathing System 161 Supervised Breathing Training Room 162 Display device 163 Chest 164 Secondary imaging device 166 First Movable Arm 168 Second Movable Arm 170 Rail 173 Bed or table 174 Movement direction of movable arms 166, 168 180 Head-Mounted Display 200 CT Imaging System 202 detector element 204 Subject 206 Center of rotation 208 Guided Breathing System 214 Data Acquisition System (DAS) 232 Display device 300 First Workflow 350 Second Workflow 400 Examples of how to generate and display interactive visualizations 500 Example Method for Training a Subject in Guided Breathing 550 Procedure for measuring subject's chest movement during guided breathing 600 Method for registering point clouds corresponding to the surface of a subject's chest 700 Exemplary method for performing a medical imaging scan on a subject 800 Segmented 3D point cloud 801 Reference Coordinate Axis 802 Surface of Interest (SOI) 804 First indicator line 806 Second indicator line 810 First Direction 811 Second Direction 814 First Boundary Plane 816 Second Boundary Plane 850 separated point clouds 900 Breathing Visualization Examples 902 Display device 903 screens 904 Virtual morphological representation of the chest area 906 Visual representation of the chest 908 Time Series Line 909 signs 910 Breathing instructions 912, 914, 916, 918 Time Series Line Sections 920 First End 921 Second End 1000 Respiration Graph 1002 First breathing pattern plot 1003 First Intake 1004 Second breathing pattern plot 1005 Exhalation 1007 Second Intake 1010 First Intake 1011 Point of maximum expansion 1012 Exhalation 1013 Point of minimum contraction 1020, 1022 Distance between the point of maximum expansion and the point of minimum contraction 1030 Upward Peak Direction 1032 Downward Peak Direction 1040 Point of maximum expansion 1042 Point of Minimum Contraction

Claims

1. 1. A method for a medical imaging system, comprising: generating a three-dimensional (3D) virtual representation of a portion of the chest or chest and abdomen of a subject of the medical imaging system via a sensor system of the medical imaging system that acquires data of the surface of the surface, the portion being dimensionally adjustable by an operator of the medical imaging system; displaying changes in the 3D virtual representation in real time on a display device of the medical imaging system to the subject while the subject is breathing; displaying instructions on the display device to the subject to perform guided breathing according to the selected breathing pattern; In response to detecting a deviation in the subject's respiratory pattern from the selected respiratory pattern, indicating the deviation to the subject. Prepare for this. the selected breathing pattern includes minimal chest expansion during inspiration and minimal chest contraction during expiration; The method, wherein displaying the instructions to perform guided breathing according to the selected breathing pattern further includes displaying a breathing guide model generated based on the 3D virtual representation for the subject to follow.

2. Indicating the deviation to the subject as a result of detecting the deviation includes: in response to determining that the deviation exceeds a deviation threshold; displaying an indication of the deviation on the display device; illuminating lights or visual markers contained in the environment of said medical imaging system; illuminating a light or visual indicator of said medical imaging system; providing tactile feedback to the subject; and providing an audible notification of said deviation; Do at least one of the following: The method of claim 1 further comprising:

3. Detecting that the deviation exceeds the deviation threshold includes: During the first stage of guided breathing: instructing the subject to inhale and hold their breath; generating a first reference set of 3D points associated with the portion of the surface of the subject while the subject is holding their breath; At equal intervals while the subject is performing the instructed breathing, generating a set of 3D points associated with said portion of said surface; calculating a Euclidean distance between the first reference set of 3D points and the generated set of 3D points; determining whether the Euclidean distance exceeds a distance threshold; During the second stage of guided breathing: instructing the subject to exhale and hold their breath; generating a second reference set of 3D points associated with the portion of the surface while the subject is holding their breath; At equal intervals while the subject is performing the instructed breathing, generating a set of 3D points associated with said portion of said surface; calculating a Euclidean distance between the second reference set of 3D points and the generated set of 3D points; determining whether the Euclidean distance exceeds a distance threshold; The method of claim 2 further comprising:

4. Displaying the instructions to perform guided breathing according to the selected breathing pattern includes: displaying instructions indicating when the subject should inhale, when the subject should exhale, and when the subject should hold their breath; Displaying a timeline showing the progression of the guided breathing through the first stage of guided breathing and the second stage of guided breathing. The method of claim 3 further comprising:

5. Generating the set of 3D points associated with the portion of the surface comprises: acquiring data of the surface via one of a LiDAR system and a 3D camera; creating a 3D point cloud based on the data; Isolating a portion of the 3D point cloud associated with the portion of the surface; Measure the 3D coordinates of the separated portion. The method of claim 3 further comprising:

6. 6. The method of claim 5, wherein the portion of the surface is defined by an operator of the medical imaging system based on a scanning protocol and a position of a visual element adjusted by the operator in the visualization of the 3D point cloud.

7. 6. The method of claim 5, wherein the one of the LiDAR system and the 3D camera is included in the medical imaging system, and the data is acquired while the subject is placed on a table of the medical imaging system.

8. 6. The method of claim 5, wherein the one of the LiDAR system and the 3D camera is contained in a guided breathing exercise room, and the data is acquired while the subject is preparing for scanning in the guided breathing exercise room.

9. 6. The method of claim 5, wherein the breathing guide model indicates a target movement of an individualized modified shape of the 3D virtual representation that is superimposed on the 3D virtual representation while the subject is breathing.

10. Displaying the breathing guide model includes: During a first breathing cycle, which includes one inspiration and one expiration, storing the 3D virtual representation of the portion of the surface for each time increment of a plurality of time increments over the first respiratory cycle; applying a transformation function to the virtual representation to generate a target virtual representation for each time increment; during each subsequent respiratory cycle, displaying each target 3D virtual representation at each time increment over the subsequent respiratory cycle; 10. The method of claim 9, further comprising:

11. Displaying the breathing guide model includes: displaying the target 3D virtual representation for each time increment of a plurality of time increments through each respiratory cycle, the respiratory cycle including one inspiration and one expiration, the target 3D virtual representation being based on a distance between each point of the first cloud of points and a corresponding point of the second cloud of points and an elapsed time of the respiratory cycle.

10. The method of claim 9.

12. a modality of the medical imaging system, X-ray, Computed tomography (CT), Magnetic resonance imaging (MR), Positron Emission Tomography (PET), or Nuclear Medicine (NM) Imaging The method of claim 1 , comprising:

13. The method of claim 1 , wherein the selected breathing pattern is selected by the operator from a plurality of breathing patterns based on a scanning protocol, an anatomical location of the subject, and / or characteristics of the subject.

14. 10. The method of claim 1, further comprising generating a stability score for the subject based on stability of the subject's chest during the subject's performance of the guided breathing during the medical imaging scan, and storing the stability score in scan data acquired during the medical imaging scan.

15. 1. A medical imaging system having an x-ray controller including one or more processors, the processors having executable instructions stored in a non-transitory memory of the medical imaging system that, when executed, cause the one or more processors to: generating a three-dimensional (3D) virtual representation of a portion of the surface of the chest or chest and abdomen of a subject of the medical imaging system, the portion being dimensionally adjustable by an operator of the medical imaging system; displaying the changes in the 3D virtual representation in real time on a display device of the medical imaging system to the subject while the subject is performing the guided breathing; displaying instructions on the display device to the subject to perform the guided breathing according to a selected breathing pattern using the 3D virtual representation as a guide; In response to detecting a deviation in the subject's respiratory pattern from the selected respiratory pattern, indicating the deviation to the subject. Let it be done, the selected breathing pattern includes minimal chest expansion during inspiration and minimal chest contraction during expiration; A medical imaging system, wherein displaying the instructions to perform guided breathing according to the selected breathing pattern further includes displaying a breathing guide model generated based on the 3D virtual representation for the subject to follow.

16. The one or more processors are configured to display the instructions to the subject and detect the deviation of the subject's breathing pattern from the selected breathing pattern based on further instructions stored in the non-transitory memory, the further instructions, when executed, causing the one or more processors to: During the first stage of guided breathing: instructing the subject to inhale and hold their breath; generating a first reference set of 3D points associated with the portion of the surface of the subject while the subject is holding their breath; At equal intervals while the subject is performing the instructed breathing, generating a set of 3D points associated with said portion of said surface; calculating a Euclidean distance between the first reference set of 3D points and the generated set of 3D points; determining whether the Euclidean distance exceeds a distance threshold; During the second stage of guided breathing: instructing the subject to exhale and hold their breath; generating a second reference set of 3D points associated with the portion of the surface while the subject is holding their breath; At equal intervals while the subject is performing the instructed breathing, generating a set of 3D points associated with said portion of said surface; calculating a Euclidean distance between the second reference set of 3D points and the generated set of 3D points; determining whether the Euclidean distance exceeds a distance threshold; 16. The medical imaging system of claim 15, wherein the medical imaging system performs the following steps:

17. The one or more processors are configured to generate the set of 3D points associated with the portion of the surface based on further instructions stored in the non-transitory memory, the further instructions, when executed, causing the one or more processors to: creating a 3D point cloud from data of the surface acquired via one of a LiDAR system and a 3D camera; segmenting the 3D point cloud to eliminate points that are not included in the object; Isolating a first portion of a first 3D point cloud associated with the portion of the surface; measuring 3D coordinates of the isolated first portion to generate the set of 3D points associated with the portion of the surface; 17. The medical imaging system of claim 16, wherein the medical imaging system performs the following.

18. 17. The medical imaging system of claim 16, further instructions stored in the non-transitory memory of the medical imaging system, which when executed cause the one or more processors to display a breathing guide model generated based on the 3D virtual representation for the subject to follow during the supervised breathing, the breathing guide model indicating a target motion of an individualized modified shape of the 3D virtual representation superimposed on the 3D virtual representation while the subject is breathing, the target motion including displaying a target 3D virtual representation at each time increment of a plurality of time increments over a plurality of respiratory cycles of the supervised breathing, each respiratory cycle including one inhalation and one exhalation, the target 3D virtual representation being based on a distance between the first reference set of 3D points and the second reference set of 3D points and an elapsed time of the respiratory cycle.

19. 16. The medical imaging system of claim 15, further instructions stored in the non-transitory memory of the medical imaging system, the further instructions, when executed, causing the one or more processors to generate a stability score for the subject based on stability of the subject's chest during performance of the guided breathing during the medical imaging scan, and store the stability score in scan data acquired during the medical imaging scan.

20. 20. A medical imaging system according to any one of claims 15 to 19, wherein the display device is a head-mounted display.

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