Coached 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] SUMMARY OF THE DISCLOSURE Embodiments of the subject matter disclosed herein relate to medical imaging systems. [Background technology]

[0002] In a medical imaging system, a scanner generates signals based on detected radiation that is used to form an image of the body of the scanned subject. The radiation may include x-rays that are directed toward and attenuated by the subject in the case of computed tomography (CT) imaging, or radiation may be emitted by a radioactive tracer introduced into the subject in the case of positron emission tomography (PET) imaging, magnetic resonance (MR) imaging, and / or nuclear medicine (NM) imaging. The subject may be carefully positioned on the table of the medical imaging system to detect radiation from specific areas of interest in the patient's body while avoiding tissue in other areas. During the scan, the quality of the images obtained may depend on the patient's body remaining still and immobile, so 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 inside the medical imaging system may create or increase a patient's level of anxiety, 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. In addition, personalized instruction increases the amount of time used to prepare a patient for a scan, which can result in inefficient utilization of medical imaging systems and scheduling delays.

[0005] Various approaches have been taken to reduce the reliance on human intervention in guided breathing by using visual instruments to help the user 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 the subject during a scan and displaying an avatar of the subject in a virtual environment that represents the subject's real-time physical position so that the subject can adjust his or her physical position using the avatar as a guide. However, Giap's motion detection system relies on a computationally intensive virtual reality system and on placing 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] Other approaches include using surface contour data of the patient's chest to generate a 3D visualization of the patient's chest in real time. The 3D visualization may be displayed to the patient, who can use the 3D visualization to control his or her breathing. For example, U.S. Pat. No. 7,869,562 to Khamene teaches using an optical imaging system to create a mesh topology of the patient and display changes in the topology as biofeedback for the patient to reproduce a predetermined breathing state (e.g., coached breathing). WO2021228703 also teaches using an interactive repositioning guide configured to use 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 advise the patient to make 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 breathing 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 the optical or LiDAR imaging system increases the amount of data collected by the medical imaging system, and the inclusion of the 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 shortcoming 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 a scan, the patient's breathing may change during the scan without the patient realizing 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 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 one or more of the problems set forth above, at least in part, by a method for a medical imaging system, comprising: 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 guided breathing according to a selected breathing pattern using the 3D virtual representation as a guide, and indicating the deviation to the subject in response to detecting a deviation of the subject's breathing pattern from the selected breathing pattern.

[0010] The above 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 above 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, and the scope of the claimed subject matter is uniquely defined by the claims that follow the detailed description. Moreover, the claimed subject matter is not limited to implementations that solve any of the shortcomings described above or in any part of this disclosure. [Brief description 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 schematic diagram of an imaging system in accordance with one or more embodiments of the present disclosure. [Figure 1B] A diagram showing 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. [Diagram 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. 13 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 diagram illustrating an example method for measuring subject's chest movement during guided 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 breast 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 a LiDAR generated in accordance with one or more embodiments of the present disclosure. [Figure 9] 8A and 8B are diagrams illustrating examples of display 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 show certain aspects of the described systems and methods. Together with the following description, the drawings illustrate and explain the structures, methods, and principles described herein. In the drawings, 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 PREFERRED EMBODIMENTS

[0014] Descriptions and embodiments of the subject matter disclosed herein relate to methods and systems for enhancing the quality of medical images produced by a medical imaging system, which 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 of the scan is typically placed on a table of the medical imaging system. The position of the table is adjusted by an operator of the medical imaging system to position the subject within the gantry. During the scan, movement of the subject may generate noise in the resulting image 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 image.

[0015] Minimizing subject motion may include coaching the subject's breathing, especially when the scan is directed to the subject's abdomen, chest, or other body parts that may move during breathing. To ensure that 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 a number of breathing patterns based, for example, on the scanning protocol, the anatomical location, and / or the subject's characteristics (such as size and breath-holding ability). The breathing pattern may include a combination of different types of breathing, including deep breathing, shallow breathing, hyperventilation, breath-holding, or inhaling and exhaling different volumes of air. The selected breathing pattern may limit the range of motion of the abdomen, chest, or other parts during inhalation and exhalation. Specifically, the subject may be instructed to minimize chest expansion during inspiration and chest contraction during expiration, to hold their breath for some amount of time, and / or to breathe at a desired rate (e.g., slowly).

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

[0017] Herein, a method and system for a guided breathing system that can be integrated into a medical imaging system is proposed. An example of a medical imaging system that can be used to perform contrast scanning according to the present technique is shown in Fig. 1A and Fig. 2. The medical imaging system includes a guided breathing device that trains a subject to minimize the subject's 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 Fig. 1A. The guided breathing device can also include a head-mounted display as shown in Fig. 1B. According to a first workflow shown in Fig. 3A, a first type of guided breathing device can be used to train the subject in a training room as shown in Fig. 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 Fig. 3B, a training room may not be used 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 Fig. 4. A subject may be trained according to one or more steps of the method of FIG. 5A and FIG. 5B, which may rely on using LiDAR, 3D camera, or similar technology to register two or more sets of points, referred to herein as point clouds, that represent the surface contour of the subject, as described in connection with the method of FIG. 6. An example of a 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 the two or more point clouds may be used to determine a target range of motion for the subject's chest. The target range of motion may 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 the term "thorax" as referred to herein for purposes of this disclosure may include the abdominal portion of a subject of interest without departing from the scope of this disclosure, and thus, any reference to a 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. Although 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, the 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 a foreign object present in a body, such as a dental implant, a stent, and / or a contrast agent. In one embodiment, the 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 lying on a table 114. Specifically, the X-ray source 104 is configured to project the beam of X-ray radiation 106 toward a detector array 108 disposed on the opposite side of the gantry 102. Although FIG. 1A illustrates 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 obtain 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 low kVp and the other at high kVp, to create dual energy projections. Thus, it should be appreciated that the methods described herein may be embodied 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 the 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 patient 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 that 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 of the array generates a separate electrical signal that is a measurement of the x-ray beam attenuation at the detector location. Separate attenuation measurements from all detector elements are acquired to generate a transmission profile.

[0023] In some medical imaging systems, the x-ray source and detector array are rotated with a gantry in the imaging plane around the object so that the angle at which the x-ray beam intersects the object is constantly changing. A set 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 revolution of the x-ray source and detector.

[0024] As described in more 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., guided breathing) in a manner that minimizes movement of the respiratory parts 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, the CT imaging system 100 includes a coached breathing system. Some components of the coached breathing system may be integrated into the CT imaging system 100 and other components of the coached breathing system may be separate from the CT imaging system 100. For example, some components of the coached breathing system may be integrated into either the gantry 102, the image processing unit 110, or a different component of the CT imaging system 100. Furthermore, in some embodiments, a first type of coached breathing system may be integrated into the CT imaging system 100 and a second type of coached breathing system may be separate from the CT imaging system 100. For example, the second type of coached breathing system may be used to train the subject 112 to control his or her breathing in a location different from the 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 the subject 112 to control his or her breathing during a scan performed with the 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 displayed on the patient display device 130. The visualizations can be used to train the subject 112 to remain stationary during the scan and minimize movement of these body parts. For example, the visualizations can be used to train the subject 112 to control his or her breathing to reduce chest movement. Generation of the visualizations is described in more detail below with reference to Figures 4-9.

[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 such that the display may be freely rotated 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 joint or a similar type of coupling that allows the patient display 130 to be freely rotated 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 such that when the subject 112 is lying on the table 114, the subject may view the visualizations displayed on the patient display 130 with minimal adjustment of the subject's 112 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 an 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, the display device 130 may not be coupled to the CT imaging system 100. For example, the display device 130 may be disposed on a cart or included in a chassis of a mobile device or system that may be positioned in a suitable location adjacent the table 114 and the subject 112. Additionally, in some embodiments, the CT imaging system 100 may not include a display device 130. For example, in some embodiments, feedback regarding the performance of guided breathing may be provided to the subject 112 via one or more illuminated portions and / or lights disposed on the inner surface 120 of the gantry 102, the edge 121 of the gantry 102, or the front surface 122 of the 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 may view the visualization with his or her head in various positions (e.g., without having to tilt his or her head or twist his or her neck to view the visualization). Additionally, the subject 112 may be able to 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 training room 161. The coached breathing training room 161 includes a couch or table 173 on which the subject 112 may rest during training in 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 in a different position than 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 may be positioned above and / or near a chest 163 of the subject 112 and the display 162 may be positioned and oriented such that the subject 112 can view the screen of the display 162 while training with the guided breathing system. The secondary imaging device 164 and the display 162 may be the same as or similar to the secondary imaging device 105 and the display 130 of the CT imaging system 100. In one embodiment, the secondary imaging device 164 and the display 162 are movably 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 162 along the rail 170 may be adjusted to accommodate a variety of subjects of different sizes. For example, first movable arm 166 and second movable arm 168 may be slidably coupled to rail 170 such that first movable arm 166 and second movable arm 168 may independently slide along rail 170 in either of two directions indicated by arrow 174.

[0034] In some embodiments, the second type of coached breathing system 160 may include an LED light 172 that may be configured to indicate to the subject 112 whether the movement of the chest 163 of the subject 112 due to breathing is within a desired range of motion during training with the coached breathing system. The desired range of motion may be based on a breathing pattern, which may 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 fast or rough breathing rate, the movement of the chest 163 may not be within the desired range of motion. As a result of the movement of the chest 163 not being within the desired range of motion, the LED light 172 may be turned on. If the subject 112 is breathing at a second slower and shallower breathing rate, the movement of the chest 163 may be within the desired range of motion, and the LED light 172 may 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 switched 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 of 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 of the desired range of motion. In this manner, by monitoring the LED light 172, the subject 112 can be trained to regulate his 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 the display device 162. The instructions may include written instructions or audible instructions, or both written and audible instructions. In addition, as described in more detail below, a visualization of the subject's breathing may be displayed on the 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, such that the subject may 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, subject 112 may be scanned. During the scan, subject 112 may monitor his or her breathing using a 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 an object 204 (e.g., object 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 object 204 (e.g., a patient) to obtain corresponding projection data. In some embodiments, the detector array 108 may be fabricated in a multi-slice configuration that includes 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 obtain projection data.

[0038] In some embodiments, the CT imaging system 200 is configured to acquire desired projection data traversing different angular positions about the object 204. Thus, the gantry 102 and the components mounted to the gantry 102 may be configured to rotate about a center of rotation 206 to acquire projection data at, for example, different energy levels. Alternatively, in embodiments where the projection angle relative to the 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 the line integrals of the attenuation coefficients of the object 204 being scanned. The processed data is generally referred to as a projection. In some examples, the individual detectors or detector elements 202 of the detector array 108 may include photon counting detectors that record individual photon interactions into 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 used for 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 related 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 the two basis materials. The density images may be displayed to show these features. In a conventional approach to diagnosing a medical condition, such as a disease state, or more generally a medical event, a radiologist or physician would review a hard copy or display of the density image to discern characteristic features of interest. Such features may include lesions, size and shape of particular anatomical sites or organs, as well as other features discernible in the image based on the skill and expertise of the individual physician.

[0042] In one embodiment, the CT imaging system 200 includes control mechanisms that control 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 into a digital signal 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 device or mass storage 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, computing device 216 provides commands and parameters to one or more of DAS 214, X-ray controller 210, and gantry motor controller 212 to control system operations such as data acquisition and / or processing. In some embodiments, computing device 216 controls system operations based on operator input. Computing device 216 receives operator input including, for example, commands and / or scanning parameters, via operatively coupled operator console 220. Operator console 220 may include a keyboard (not shown) or 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 the CT imaging system 200, for example, to input and output system parameters, request exams, plot data, and / or view images. Additionally, in some embodiments, the CT imaging system 200 may be coupled to multiple displays, printers, workstations, and / or similar devices that may be located locally, such as within a facility or hospital, or remotely, such as 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 embodiment, PACS 224 is further coupled to remote systems, 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 access 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, the DAS 214 samples and digitizes the projection data acquired by the detector elements 202. The image reconstructor 230 then performs high speed reconstruction using the sampled and digitized x-ray data. Although FIG. 2 illustrates the image reconstructor 230 as a separate entity, in some embodiments, the image reconstructor 230 may form part of the computing device 216. Alternatively, the image reconstructor 230 may not be present in the CT imaging system 200, and instead the computing device 216 may perform one or more functions of the image reconstructor 230. Also, the image reconstructor 230 may be located locally or remotely, and may be operatively connected to the CT imaging system 200 using a wired or wireless network. In particular, an example embodiment may utilize the computational resources of a "cloud" network cluster for the image reconstructor 230.

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

[0050] The 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 the secondary imaging device 105 and the patient display device 130, the coached breathing system 208 includes a secondary imaging device controller 240 and a position data processing unit 242. The secondary imaging device controller 240 may be configured to control the secondary imaging device 105. In various embodiments, the secondary imaging device 105 may cover a 360-degree view of each portion of the subject 112 inside the gantry 102. In some embodiments, multiple secondary imaging devices 105 may be positioned at different positions around the gantry 102 such that a 360-degree view of each portion of the subject 112 inside the 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 if 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 to adjust his or her breathing to reduce the motion of his or her respiratory region using the visualization displayed on the patient display 130 as described above. The processing of image data by the position data processing unit 242 is described in further detail below in connection with Figures 4-7.

[0052] FIG. 3A illustrates a first workflow 300 of how a coached breathing system, such as the coached breathing system 208 of FIG. 2, may 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) may be trained with the coached breathing system prior to performing a scan. During training, the subject may view an interactive visualization of a portion of the subject's chest on a display screen, such as a screen of display device 162 described above with respect to FIG. 1C or a head-mounted display, such as head-mounted display 180 described above with respect to FIG. 1B. As described in more detail below, the interactive visualization may include a 3D virtual representation of the surface of the chest while the subject is breathing. As the subject is breathing, the interactive visualization may change to show the subject how the chest moves while breathing. For example, the 3D virtual representation may expand during the subject's inspiration and contract during the subject's expiration.

[0053] The subject can change his / her breathing pattern, i.e., the manner in which he / she breathes, and can indicate this change via the 3D virtual representation. The interactive visualization can indicate a target or reference position of 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 way, by viewing his / her breathing in the interactive visualization along with the target or reference position, the subject can adjust his / her 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 way, the subject can learn to breathe in a manner that minimizes movement of the respiratory parts of his / her body, which can prevent possible noise and improve the quality of the images reconstructed from the scan.

[0054] As an example, a subject may feel anxious in anticipation of a CT scan. As a result of the anxiety, the subject may breathe in an irregular, heavy, deep, or rapid manner. Because performing a scan on a subject while the subject is breathing in an irregular, heavy, deep, or rapid manner may introduce noise artifacts into the images obtained from the scan due to excessive movement of the subject's chest, a guided breathing system may be used to train the subject to control his or her breathing. A 3D camera, LiDAR laser, or similar remote sensing technology may be positioned above the subject's chest to capture the surface contour of the chest. The surface contour may be displayed on a display device via an interactive visualization that allows the subject to visualize the movement of his or her 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 the chest has expanded beyond a desired (e.g., threshold) expansion. For example, a visual component of the interactive visualization can be illuminated or brightened to indicate excessive expansion. Additionally or alternatively, an LED light on or near the indicator (LED light 172 in FIG. 1C) may be illuminated to indicate excessive expansion. As a result of viewing excessive expansion, the subject can attempt to suppress inspiration to reduce chest movement.

[0056] In various embodiments, training with the coached breathing system may occur at a location different from the medical imaging system. For example, training with the coached breathing system may occur in a coached breathing training room, such as coached breathing training room 161 of FIG. 1C. An advantage of training the subject in the coached breathing training room rather than the medical imaging system is that it may reduce the subject's level of anxiety in anticipation of the scan. Additionally, the amount of time available for the subject to train in the coached breathing training 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 table (e.g., table 114) of a medical imaging system 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 help an operator align an x-ray source (e.g., x-ray source 104) of the medical imaging system with respect to 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 that contains the ROI into the imaging plane of the gantry.

[0058] Once the subject is appropriately positioned to perform the scan, in a third block 306 of the first workflow 300, the subject can practice and / or be instructed on coaching breathing using the coaching breathing system. For example, the subject can view one type of interactive visualization described above on a display device (e.g., patient display device 130 of FIG. 1A) coupled to the medical imaging system. 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 coaching breathing with the aid of the visualization until the movement of his / her chest is within a threshold motion range defined by the target or reference position.

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

[0060] FIG. 3B illustrates a second workflow 350 of 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 to train the subject is too short to justify using the 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 being 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 visualizations 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 including a guided breathing system such as the 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., 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 a non-limiting example of the CT imaging system 100 of FIG. 1A and / or the 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 included 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 the position data processing unit 242 of FIG. 2.

[0062] Method 400 begins at block 402, where the method includes scanning a subject with 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 ​​a table or couch on which the subject is positioned and is detected at 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 a number of 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 number of points.

[0063] At block 404, the method 400 includes obtaining, processing, and segmenting the LiDAR data. The surface contour points are generated as a collection of points in three dimensions, which are 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 may be performed to identify points of the point cloud that represent the surface contour of the subject's body from points of the point cloud that represent one or more surfaces of the table or couch (or other components of or disposed in the medical imaging system). The segmentation process may use various techniques and methods known in the art. In one embodiment, a density-based spatial clustering of objects with noise (DBSCAN) is used to segment the obtained LiDAR data.

[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 of the guided breathing system (e.g., patient display 130 of FIG. 1A or display 162 of FIG. 1C) on the segmented 3D region. In some embodiments, the SOI may alternatively be presented on a display of the medical imaging system (e.g., display 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 abdomen of the subject. As a result of the scanning protocol indicating that the ROI is located in the abdomen, the SOI may be presented on the segmented 3D region via a visual indicator, such as an index line defining the initial SOI, superimposed on the segmented 3D region.

[0065] 8A, a segmented 3D point cloud 800 of a surface of a subject's chest is shown, which may be generated from a LiDAR light source as described with respect to FIG. 4 and displayed on a display screen. A SOI 802 is shown in the segmented 3D point cloud 800 by a first index line 804 and a second index line 806, and includes points of the segmented 3D point cloud 800 that are located 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 are located between a first boundary plane 814 in the y dimension (shown in 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 may be adjusted by adjusting the position of one or both of the first and second index lines 804 and 806 (and corresponding boundary planes 814 and 816) in a first direction 810 or a second direction 811 in the segmented 3D point cloud 800. For example, the size of the SOI 802 may 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 may 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 or technician of a medical imaging system instructing a subject on coached breathing, or a caregiver) can indicate to the coached breathing system a set of points to be selected from the segmented 3D point cloud 800 and that can be 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 the present 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, the method 400 proceeds to block 408. At block 408, the method 400 includes modifying the initial SOI based on input received from a user. For example, the input received from a 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 of the segmented 3D point cloud of the subject's chest that are located between a first plane defined by a first index line of the accepted SOI and a second plane defined by a second index line of the accepted SOI (e.g., boundary plane 814 and boundary plane 816).

[0071] Figure 8B illustrates a separated point cloud 850 that may be selected from the segmented 3D point cloud 800 of Figure 8A based on the SOI 802. The separated point cloud 850 may include points of the 3D point cloud 800 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 having a Z coordinate 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 morphology 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 as the subject breathes, the virtual morphology representation adjusts in real time in response. For example, as the subject inhales, the subject may see the virtual morphology representation expand on the display device, and as the subject exhales, the subject may see the virtual morphology representation contract on the display device.

[0073] Referring to Figure 9, an exemplary respiratory visualization 900 is shown, where 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 device 180 of Figure 1B, and / or the display device 162 of Figure 1C. The respiratory visualization 900 may be displayed to a subject of a medical imaging system during training in coached breathing, as previously described.

[0074] The respiratory visualization 900 includes a visual representation 906 of a 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 view the movement of his or her 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, the "inhale" instruction can be displayed on the screen 903 at the time 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, the "exhale" instruction can be displayed or illuminated on the screen 903 at the time 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 the 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 the 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 a 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 inhalation phase of the coached breathing and a second exhalation 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. A first segment 912 and a 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 with respect 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 his breath after inhalation, and a first set of reference points is generated during the breath hold. The second segment 914 may correspond to a time during which the motion of the subject's chest is monitored. A third segment 916 and a 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 with respect 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 exhalation 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 section 912, the second section 914, the third section 916, and the fourth section 918 may be visually distinguishable from one another, for example, via color coding or shading. For example, the first section 912 may have a first color or shading, the second section 914 may have a second color or shading, the third section 916 may have a third color or shading, and the fourth section 918 may have a fourth color or shading (or may have a color coding or shading similar to the second section 914). In this way, the subject may visually determine in which portion of the respiratory cycle he or she is currently located during the exercise and determine how much time is remaining until the subsequent portion 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] Further, in some embodiments, a 3D coached breathing model may be generated and displayed on the screen 903 together 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 way, the target 3D virtual representation may model a target motion of the subject's chest. For example, the coached breathing model may be aligned 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 the breathing cycle, such that the subject may adjust his / her breathing to match a first position of the virtual morphological representation 904 with a second position of the coached breathing model.

[0081] The advantage of using a coached breathing model, which is generated based on the acquired LiDAR / 3D camera data, is that the coached breathing model can indicate in an individualized manner how a particular subject's chest should move during breathing. For example, not all points on the chest move up and down or in the same direction at the same time during breathing. Some breathing patterns involve breathing from the diaphragm, while other breathing patterns involve breathing with the chest muscles. By attempting to match the coached breathing model to the virtual morphology representation 904, the subject can achieve the selected breathing pattern more quickly and efficiently. In addition, the coached breathing model may "gamify" the task of achieving the selected breathing pattern, where the visual task of matching the coached breathing model to the virtual morphology representation 904 is easier, more fun, and / or more engaging than following the breathing instructions 910. The generation of the coached breathing model is described below with reference to FIG. 5A.

[0082] Returning to Figure 4, at block 412, the method 400 includes training the subject with on-screen training instructions (e.g., breathing instructions 910) and a virtual morphological representation of a portion of the subject's chest surface (e.g., virtual morphological representation 904) for self-calibration of the breathing pattern by the subject. Training the subject for self-calibration of the breathing pattern is described in further detail below with respect to Figure 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 a 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 is shown 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. 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 of the guided breathing system, such as display 130 of FIGURE 1A and / or display 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 and 10 minutes for an adult. In various embodiments, the coached breathing includes a first phase and a second phase. In the first phase, motion of the subject's chest is monitored and measured with respect 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, motion of the subject's chest is monitored and measured with respect 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 contracted 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 set to the inspiration state, the inspiration phase of the coached breathing can be started. 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 if the range of motion of the subject's chest exceeds a threshold range of motion. Instructions can be displayed on the screen for the subject to perform an inspiration. For example, as described above with respect to FIG. 9, written instructions to inhale for the duration of the inspiration can be displayed or lit on the screen. Additionally, the inspiration state can be indicated on a timeline line (e.g., timeline line 908) displayed on the screen, for example, via lighting or highlighting a portion of the timeline line corresponding to the duration of the desired inspiration, an arrow (e.g., indicator 909) indicating the current time relative to the timeline line, or a different visual indicator. For example, the duration of the desired inspiration can be five seconds. Instructions can be displayed on the screen for the subject to hold their breath for a first predetermined duration after performing an inspiration. 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 a surface of the subject's chest (and / or abdomen). Registering the first cloud of reference points based on the LiDAR data is described in further detail with respect to FIG.

[0089] 6 illustrates a method 600 for registering a point cloud corresponding to a surface of a chest of a subject 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.

[0090] At block 602, the method 600 includes acquiring a first set of LiDAR data. The LiDAR data may be acquired via a LiDAR imager of the 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, the 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 a surface of the subject's chest. At block 606, the method 600 includes performing a segmentation step 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 respect 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 are within the marker line.

[0093] At block 610, method 600 includes converting the separated point cloud corresponding to the SOI into 3D coordinates for display on a display device of the guided 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 guided breathing, as described above with respect to FIG. 5A.

[0094] Returning to FIG. 5A, in block 508, displaying instructions and monitoring the guided breathing includes measuring the subject's chest movement relative to a first set of reference points. Instructions may be displayed on a screen so that the subject breathes according to a predetermined breathing pattern. For example, as described above with respect to FIG. 9, a written instruction to inhale may be displayed or illuminated on the screen for the duration of a required inhalation, and a written instruction to exhale may be displayed or illuminated on the screen for the duration of a required exhalation, according to the predetermined breathing pattern. In addition, in some breathing patterns, the subject may be instructed to hold his / her 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 subject chest movement during coached breathing with 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 equal intervals, such as every millisecond.

[0096] Method 550 begins at block 551, where method 550 includes receiving a set of reference points. The set of reference points may be a set of points corresponding to a surface of a subject's chest at an initial time point for which other sets of points corresponding to the surface of the subject's chest are measured during guided breathing. For example, the set 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 set 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 set of reference points in FIG. 5A).

[0097] At block 552, the method 550 includes generating a point cloud corresponding to a surface of the subject's chest while the subject is breathing (e.g., following 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, the method 550 includes calculating a distance metric between the points of the reference point cloud and the points of 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 of the first point cloud and a corresponding point of the second point cloud. For example, the distance metric may be the average Euclidean distance of 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 the first and second clouds of points corresponding to an upper part of the chest to a greater extent than portions of the first and second clouds of points corresponding to a 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 the first and second clouds of points corresponding to a lower part of the chest to a greater extent than portions of the first and second clouds of points corresponding to an upper part of the chest when breathing. If the subject is trained to conform to a first respiratory pattern, the Euclidean distance between points of the first cloud of points and points of the second cloud of points corresponding to an upper part of the chest may be weighted more heavily than the Euclidean distance between points of the first cloud of points and points of 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 of the first cloud of points and points of the second cloud of points corresponding to a lower part of the chest may be weighted more heavily than the Euclidean distance between points of the first cloud of points and points of 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 thorax 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 thorax has exceeded the desired parameters of the respiratory pattern and the subject is not breathing according to the selected respiratory pattern.

[0101] 10, a respiratory graph 1000 shows two plots, a first plot 1002 showing a first exemplary respiratory pattern of a subject and a second plot 1004 showing a second exemplary respiratory pattern of the subject. Time is shown on the x-axis of the respiratory 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 the respiratory 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. A 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. The 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 a maximum expansion of the subject's chest during the first inspiration 1010 at point 1011 and a minimum contraction of the subject's chest during expiration 1012 at point 1013. The distance 1022 may be greater 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 but considered 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 may be notified on a display of the coached breathing system. For example, a visual indication that the subject is not adhering to a breathing pattern may be displayed on the display in writing or by the appearance of a graphic element, or by lighting, brightening, or displaying an existing element 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 of 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 audible notification (e.g., a voice or a voice recording) played by a speaker of the coached breathing system and / or in the subject's environment, via tactile feedback (e.g., vibration), or via a different manner.

[0106] If, at block 556 , it is determined that the estimated range of motion does not exceed the threshold range of motion, then the subject can be presumed 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 (wherein the subject's chest movement is measured relative to an expanded chest) or an expiration phase (wherein the subject's chest movement is measured relative to a contracted chest). For example, the predetermined duration may be 10 minutes.

[0108] If in block 560 it is determined that the predetermined duration has not been reached, then method 500 returns to block 552 and continues to monitor the range of motion of the subject's chest during the next equal interval t of guided breathing. Alternatively, if in block 560 it is determined 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 be initiated. Instructions can be displayed on the screen for the subject to perform an exhalation. 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 for a contracted chest to determine whether the range of motion of the subject's chest has exceeded a threshold range of motion. The exhalation state can be indicated by a time series line 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 performing an exhalation, instructions can be displayed on the screen for the subject to hold a 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 a surface of the subject's chest (and / or abdomen) based on the LiDAR data while the subject holds a 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 the coached breathing includes measuring the subject's chest movement with respect to the second set of reference points. Instructions can be displayed on a screen so that the subject breathes according to a predetermined breathing pattern. For example, as described above with respect to FIG. 9, a written instruction to inhale can be displayed or lit on the screen for the duration of a required inhalation and a written instruction to exhale can be displayed or lit on the screen for the duration of a required exhalation according to the predetermined breathing pattern. In addition, in some breathing patterns, the subject can be instructed to hold his / her breath. The subject's chest movement can be measured while the subject breathes according to the predetermined breathing pattern. The subject's chest movement can be measured as described above with respect to FIG. 5B. As with the inspiration phase, if the subject's chest movement range is not within the threshold movement range, an indication can be given to the subject, for example via an indicator light or on a display screen of the coached breathing system. After a predetermined duration of the expiratory phase, the measurement of 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 inhalation and exhalation 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 inhalation phase may be weighted more heavily than a second average range of motion of the subject's chest during the exhalation phase, or the first average range of motion of the subject's chest during the inhalation phase may be weighted less heavily than a second average range of motion of the subject's chest during the exhalation 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. In 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. In 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 is shown for performing a medical imaging scan on a subject while the subject is performing supervised breathing. The subject may have undergone a training session for supervised breathing prior to the medical imaging scan, as described above with respect to FIG. 5A. In one embodiment, the subject is trained for supervised breathing in a first location, such as the training room shown in FIG. 1C. The subject may successfully complete the training, whereby the subject may demonstrate adherence to a selected breathing pattern for a predefined 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 inside the gantry of the imaging system. In some embodiments, the subject may be positioned on the table such that the subject can view an external display of the supervised breathing system of the imaging system, such as the display 130 of FIG. 1A. During acquisition of projection data during an examination, the subject may 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 may 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-holding time. The breath-holding time may be the duration that the subject can consistently and reliably hold breath between inhalation and exhalation, and may be determined as a result of a training session on guided breathing. Different subjects may have different breath-holding 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 that 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, and 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 the first subject and a second scan on the second subject to account for differences between the first duration and the second duration. During the first scan, the first acquisition of projection data may depend on the first duration, and during the second scan, the 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 the guided breathing. As mentioned above, during the guided breathing, the subject can follow the breathing instructions displayed on the display using a visual representation of a portion of his or her chest as a guide and / or by matching the visual representation with a 3D guided breathing model displayed on the display.

[0117] At block 706, the 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 indicative of a degree of stability of the subject's chest during breathing. For example, a high stability score may indicate that the subject was able to keep the range of motion of his / her chest within a minimum threshold motion range with high accuracy and consistency. A low stability score may indicate that the subject was not able to keep the range of motion of his / her 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 an image reconstructed from the projection data acquired during coached breathing may depend on the degree of stability of the subject's chest, such that images of higher quality may be formed from a subject with a high stability score than those formed 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 a minimum expansion of the chest and a second set of point cloud coordinates corresponding to a maximum expansion of the chest, 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 a maximum expansion of the chest and a second set of point cloud coordinates corresponding to a minimum expansion of the chest, 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 the relative movement of different parts of his / her chest and / or abdomen (e.g., upper chest breathing vs. diaphragmatic breathing), the stability score may be calculated based on the relative difference between parts of the first point cloud and corresponding parts of the second point cloud, where other parts 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 in image reconstruction. In some embodiments, 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 may also be stored in the metadata.

[0120] At block 710, the 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 the computing device 216 or mass storage 218 of FIG. 2. Including a stability score in the scan data may link the scan data with a record of the subject's performance of guided breathing during the scan, 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. The CT examination or scan may be stored with a stability score, since the stability score may be correlated with image quality. In such cases, examinations with high stability scores may be considered first, if preferred.

[0121] In addition, the stability score can 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 on 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 viewing images that do not have 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 the stability score is 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 on a display device a 3D visualization of a selected portion of a subject's chest along with breathing instructions while the subject practices or performs coached breathing, where the selected portion may be adjusted to include a smaller surface area of ​​the chest (e.g., a reduced set of points on the subject's chest) than the entire surface of the chest (e.g., across the subject's entire torso). The smaller surface area may be selected by an operator to cover a particular portion of the chest that expands and contracts during a particular breathing pattern. For example, a first breathing pattern may involve moving an upper portion of the chest associated with the subject's lungs and a second breathing pattern may involve moving a lower portion of the chest associated with the subject's diaphragm. For example, a first scan may be performed of the subject's abdomen and a second scan may be performed of the subject's lungs. The quality of the first scan may depend on the subject following the first breathing pattern and the quality of the second scan may depend on the subject following the second breathing pattern. For example, a first breathing pattern may include expanding the chest muscles to breathe while keeping the abdomen still, and a second breathing pattern may include expanding the subject's diaphragm to breathe while keeping the chest still.

[0123] In this manner, during coached breathing, the operator may view only those portions of the chest that are involved in a particular breathing pattern and not those portions of the chest that are not involved in the particular breathing pattern. By displaying selected portions, as opposed to alternative 3D visualizations that include a larger surface area, the amount of memory and / or processing resources used by the coached breathing system and / or medical imaging system to generate the 3D visualization may be reduced, and the performance and operation of the coached breathing system and / or medical imaging system may be increased. 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 may be made available for other medical imaging and / or other tasks. In addition, the subject's performance for coached breathing may be increased, 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 may 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 his breathing with respect to the 3D coached breathing model to achieve a selected breathing pattern, where the 3D coached breathing model can show the shape of the modified 3D visualization, which is personalized based on the subject's breathing, in real time. By displaying the 3D coached breathing model together with the 3D visualization of the subject's breathing, the subject can more quickly adopt the selected breathing pattern, 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, making resources available for other tasks, and improving the quality of the resulting reconstructed images. Additionally, generating the 3D coached breathing model based on the 3D visualization, rather than generating the 3D coached breathing model from scratch without relying on the 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 disclosure also corresponds to a method for a medical imaging system, the method including: generating a three-dimensional (3D) virtual representation of a portion of the surface via a sensor system of the medical imaging system acquiring data 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 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 inspiration, when to start expiration, and when to hold a breath, and displaying time series lines indicating the duration of inspiration, the duration of expiration, and the duration of the breath-hold by the subject. 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, at least one of displaying an indication of the displacement on a display device, illuminating a light or visual indicator 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 cloud of points associated with a portion of a surface of the thorax while the subject is holding a breath after inspiration, generating a second cloud of points associated with the portion of the thorax while the subject is holding a breath after expiration, and calculating a Euclidean distance between the first cloud of points and the second cloud of points to determine if the Euclidean distance exceeds a distance threshold.In a fourth example of the method, optionally including one or more of the first to third examples or each, generating either the first point cloud or the second point cloud further comprises 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 this data, isolating a portion of the 3D point cloud related to 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 to fourth examples or each, the portion of the surface of the chest is defined by an operator of the medical imaging system based on the scanning protocol and the position of a visual element adjusted by the operator in the visualization of the 3D point cloud. In a sixth example of the method, optionally including one or more of the first to fifth examples or each, 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 to 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 to seventh examples, the 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 showing 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 to eighth examples, displaying the respiratory guide model further includes storing, during a first respiratory cycle including one inspiration and one expiration, 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 displaying, during each subsequent respiratory cycle, 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 or each of the first to 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 of the first cloud of points and a corresponding point of the second cloud of points and an elapsed time of the respiratory cycle. In an eleventh example of the method, optionally including one or more or each of the first to 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 or each of the first to 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 corresponds 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 while the subject is performing guided breathing on a display device of the medical imaging system, displaying instructions to the subject on the display device to perform guided 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. In a first example of the system, detecting a deviation of the subject's respiratory pattern from a selected respiratory pattern further includes, while the subject is holding a 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 portion of the surface, and measuring 3D coordinates of the separated first portion to generate a first point cloud associated with the portion of the surface of the chest, and, while the subject is holding a 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 portion of the surface, and measuring 3D coordinates of the separated second portion to generate a second point cloud associated with the portion of the chest, 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 guided breathing exercise room, and data of the chest surface is acquired while the subject is preparing for the scan in the guided 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 a non-transitory memory of the medical imaging system which, 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 for 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 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. In a fourth example of the 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 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 disclosure also relates to a method that includes, at a first 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 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 "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. Terms such as "first" and "second" do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Additionally, 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 one object (e.g., materials, elements, structures, members, etc.) that can be connected or coupled to another object, whether the object is directly connected or coupled to the other object, or there are one or more intervening objects between the object and the other object. In addition, it should be understood that references to "one embodiment" or "an embodiment" in this disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the listed features.

[0129] In addition to any of the modifications shown above, many other variations and alternative configurations can be devised by those skilled in the art without departing from the spirit and scope of the present description, and the claims are intended to cover such modifications and configurations. Thus, while the information has been described above with specificity and detail in connection with what is currently 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, mode of operation, and usage, can be made without departing from the principles and concepts described herein. Also, 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 Table 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 150 Alternative configurations of the CT imaging system 100 160 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 Direction of movement of movable arms 166, 168 180 Head-Mounted Display 200 CT Imaging System 202 Detector element 204 Subject 206 Rotation Center 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 Exemplary Methods for Training Subjects in Guided Breathing 550 Procedure for measuring subject's chest movement during guided breathing 600 A method for registering a point cloud corresponding to a surface of a subject's chest 700 Exemplary method for performing a medical imaging scan on a subject 800 Segmented 3D points 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 points 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 Timeline segments 920 First End 921 Second End 1000 Respiration Graph 1002 First breathing pattern plot 1003 First Intake 1004 Plot of the second breathing pattern 1005 Breath 1007 Second intake 1010 First intake 1011 Point of maximum expansion 1012 Breath 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 a thoracic and / or abdominal surface of a subject of the medical imaging system via a sensor system of the medical imaging system acquiring data of said surface, said 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 relative 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. The method comprises:

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 the indication of the misalignment on the display device; illuminating lights or visual indicators contained in an 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; To 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 his / her breath; generating a first reference set of 3D points associated with the portion of the surface of the thorax and / or abdomen 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 the portion of the surface of the thorax and / or abdomen; 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 of the thorax and / or abdomen 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 the portion of the surface of the thorax and / or abdomen; 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 in accordance with 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 of the thorax and / or abdomen comprises: acquiring data of the surface of the chest and / or abdomen 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 that is 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 portions of the surface of the chest and / or abdomen are defined by an operator of the medical imaging system based on a scanning protocol and on positions of visual elements 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 a scan in the guided breathing exercise room.

9. The method of claim 5, wherein displaying the instructions to perform guided breathing according to the selected breathing pattern further comprises displaying a breathing guide model generated based on the 3D virtual representation for the subject to follow, the breathing guide model showing a target movement of an individualized modified shape of the 3D virtual representation superimposed on the 3D virtual representation while the subject is breathing.

10. Displaying the breathing guide model includes: During a first respiratory cycle, which includes one inspiration and one expiration, storing the 3D virtual representation of the portion of the surface of the thorax and / or abdomen 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 of the target 3D virtual representations for each time increment over the subsequent respiratory cycle. 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 respiratory pattern is selected by the operator from a plurality of respiratory patterns based on a scanning protocol, an anatomical location of the subject, and / or characteristics of the subject.

14. 2. The method of claim 1, further comprising generating a stability score for the subject based on stability of the thorax and / or abdomen during the subject's performance of the guided breathing during a 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 a thoracic and / or abdominal surface of a subject of the medical imaging system, said 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 performing 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. A medical imaging system that performs the above-mentioned steps.

16. The one or more processors are configured to display the instructions to the subject and detect the deviation of the subject's respiratory pattern from the selected respiratory 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 his / her breath; generating a first reference set of 3D points associated with the portion of the surface of the thorax and / or abdomen 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 the portion of the surface of the thorax and / or abdomen; 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 of the thorax and / or abdomen 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 the portion of the surface of the thorax and / or abdomen; 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, further comprising:

17. The one or more processors are configured to generate the set of 3D points associated with the portion of the surface of the thorax and / or abdomen 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 of the chest and / or abdomen 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 said portion of said surface; measuring 3D coordinates of the isolated first portion to generate the set of 3D points associated with the portion of the surface; 20. The medical imaging system of claim 16, further comprising:

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 respiratory guide model generated based on the 3D virtual representation for the subject to follow during the guided 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 a target 3D virtual representation for each time increment of a plurality of time increments over a plurality of respiratory cycles of the guided breathing, each respiratory cycle including one inspiration and one expiration, 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 that, when executed, cause the one or more processors to generate a stability score for the subject based on stability of the subject's thorax and / or abdomen during performance of the guided breathing during a medical imaging scan, and store the stability score in scan data acquired during the medical imaging scan.

20. At the 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 guided breathing; generating a stability score for the medical imaging scan based on stability of the subject's thoracic and / or abdominal regions during performance of the guided breathing by the subject; storing the stability score in the scan data acquired during the medical imaging scan; 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 a stability score of the medical imaging system; The method according to claim 1,

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