Ultrasound Imaging for Visualization and Quantification of Mitral Regurgitation

Abstract

The ultrasound system includes a processor circuit in communication with an array of acoustic elements and a display. The processor circuit receives B-mode and / or Doppler ultrasound data representative of mitral regurgitation associated with an opening of a mitral valve. The processor circuit generates a model of the opening and outputs a graphical representation of the model of the opening to the display. The processor circuit generates a blood flow model of the mitral regurgitation based on the model of the opening. The processor circuit compares the blood flow model to the Doppler data. The processor circuit modifies the model of the opening (e.g., different shape, different location, and / or different orientation) such that the blood flow model is modified to match the Doppler data. The processor circuit outputs a graphical representation of the opening having a different shape, different location, and / or different orientation to the display.

Description

[Technical field]

[0001] The present disclosure relates generally to ultrasound imaging for visualizing and quantifying blood flow in a patient. In particular, blood flow through the complex mitral valve orifice is modeled based on ultrasound data as a convolution of a simple blood flow model with multiple source points. The resulting blood flow model is compared to acquired three-dimensional color Doppler data and adjusted to ensure accuracy. [Background technology]

[0002] Ultrasound imaging is widely used in medical imaging and diagnosis. Three-dimensional color Doppler imaging measures the velocity of a patient's blood flow and conveys this information to the physician by displaying different colors on a display. Color Doppler imaging is particularly useful in identifying regurgitation of blood at the mitral valve of a patient's heart. In a healthy heart, blood flows from the left atrium through the mitral valve into the left ventricle. When the heart contracts, the mitral valve closes to prevent blood from flowing back into the left atrium, and blood is pushed out of the left ventricle into the aorta, where it is carried to the rest of the body. However, when the mitral valve does not close completely and blood flows backward from the left ventricle into the left atrium, mitral regurgitation occurs. This mitral regurgitation prevents the heart from pumping blood as efficiently as it should and can cause serious symptoms.

[0003] For a physician to prescribe the appropriate treatment for mitral regurgitation, he or she must know the extent of the condition. Specifically, they must know the amount of blood that flows back into the left atrium, i.e., volumetric blood flow, and the size of the hole or opening that occurs when the mitral valve does not close completely. Both of these metrics are very difficult to accurately quantify using traditional methods. A common method to quantify blood flow through the mitral valve is the Proximal Isovelocity Surface Area (PISA) method. In the PISA method, the mitral valve is approximated as a single pinhole in a flat, two-dimensional plane. However, because the mitral valve is neither flat nor two-dimensional, but is an irregular, dynamic, or constantly moving three-dimensional surface, and because the gap formed by the mitral valve during regurgitation has a complex shape rather than a single pinhole, the PISA method inaccurately measures both the flow rate through the mitral orifice and the area of ​​the opening. Other methods, such as computational fluid dynamics (CFD), provide more accurate measurements than the PISA method, but require a large number of computational steps and are impractical for clinical use. Consequences of using current techniques to assess and quantify mitral regurgitation include unreliable measurements, variable results, time-consuming and impractical processes, and unnecessary repeat ultrasound examinations.

[0004] EP 3 692 925 A1 relates to a method for estimating reflux based on identified reflux orifices, using a dynamic surface model and a flow convergence model.

[0005] EP 2 654 569 A1 relates to a method for quantifying mitral regurgitant flow and volumetric flow, including the use of a modelled flow velocity field.

[0006] US2019 / 125295A1 relates to a method for detecting valves in ultrasound data and detecting flow through the valves. Summary of the Invention

[0007] An embodiment of the present disclosure is a system, device, and method for visualizing and quantifying mitral regurgitation. The present disclosure overcomes inaccuracies in measuring the volumetric blood flow through a leaking mitral valve and the area of ​​the mitral valve orifice by modeling the mitral valve as a three-dimensional surface and the mitral orifice as its actual complex shape throughout systole. In particular, an ultrasound imaging system acquires three-dimensional (3D) color Doppler volume data of the mitral valve throughout the cardiac cycle. The system then identifies ultrasound image frames that show systole, the phase in which the mitral valve closes and blood is pushed out of the left ventricle. For each of these identified frames, a 3D model of the mitral valve and orifice is generated. The orifice is modeled as a number of small holes arranged next to each other in the shape of the orifice. The flow models from each of these small holes are combined to obtain a flow model of the entire orifice. This flow model is then compared to the actual ultrasound image. The system then adjusts the model to ensure accuracy by making the flow model consistent with the actual flow seen in the image. The volumetric flow rate and orifice area may be calculated based on the adjusted flow model. This process is repeated for all ultrasound images that exhibit systole.

[0008] This process advantageously provides the physician with accurate blood flow and orifice area data at all times throughout the systole of the cardiac cycle. Moreover, because this process is completed for every ultrasound image frame, it takes into account the ever-changing shape of the mitral valve and regurgitant orifice throughout systole. This process also takes into account the complex shapes of the various orifices created by the mitral valve not closing completely, including when multiple orifices are created. And by integrating the blood flow measurements throughout systole, the physician can obtain an accurate measurement of the total amount of blood that leaked from the ventricle into the atrium during a single systole. With all this information, the physician can much more accurately determine the appropriate therapeutic measures to address the condition. Moreover, the calculations of this procedure are fast enough to be completed in real time, making it amenable to use at the patient's side. The procedure is also non-invasive, which means it can be easily used to quantify mitral regurgitation before, during, or after mitral valve repair surgery. The physician can know the success of the repair immediately after the procedure, without waiting for the end of the treatment or recovery time to pass. Additionally, the flow versus time data calculated by the algorithms described herein can tell the physician whether the flow is early systolic, late systolic, or holosystolic, revealing additional information about the mechanism of reflux. Until now, this information has not been available automatically to the physician, and tedious manual tracking has been required to infer this type of time-based information.

[0009] According to one exemplary aspect, an ultrasound system is provided, the ultrasound system comprising: an array of acoustic elements for acquiring ultrasound data including Doppler data and B-mode data; and a processor circuit in communication with the array of acoustic elements and a display, the processor circuit receiving ultrasound data acquired by the array of acoustic elements, the ultrasound data representing mitral regurgitation associated with an opening of a mitral valve, generating a model of the mitral valve based on the B-mode data, generating a model of the opening based on the model of the mitral valve and the Doppler data, and outputting a first screen display on the display, the first screen display including a model of the mitral valve and a model of the opening in the model of the mitral valve. The method includes: generating a blood flow model of mitral valve regurgitation based on the model of the orifice; comparing the blood flow model to the Doppler data; modifying the model of the orifice such that the blood flow model is modified to match the Doppler data, wherein the model of the orifice is modified to have at least one of a different shape, a different position, or a different orientation; and outputting a second screen display to a display, the second screen display including an ultrasound image based on the ultrasound data and a model of the orifice in the ultrasound image, wherein the model of the orifice in the second screen display includes at least one of a different shape, a different position, or a different orientation.

[0010] The model of the mitral valve may include an anatomical model of the mitral valve. Generating the model of the orifice may include identifying an orifice in the anatomical model of the mitral valve based on the Doppler data. In some embodiments, the processor circuitry may identify the orifice based on a velocity in the Doppler data that exceeds a threshold velocity.

[0011] In some embodiments, the processor circuitry alters the shape of the orifice by altering the threshold velocity. In some embodiments, the processor circuitry alters the position of the orifice by moving the orifice along a vertical direction in a model of the mitral valve. In some embodiments, the processor circuitry outputs a 3D iso-velocity surface based on a blood flow model of mitral regurgitation.

[0012] In some embodiments, the first and / or second screen display includes a first ultrasound image based on the ultrasound data and a second ultrasound image based on the ultrasound data, the first ultrasound image having an orientation along a first axis and the second ultrasound image having an orientation along a different second axis. In some embodiments, the first ultrasound image and the second ultrasound image are (i) based on multiplanar reconstruction (MPR) or (ii) include a side view. In some embodiments, the first axis and the second axis correspond to at least one of a shape or a modified shape of the opening. In some embodiments, the processor circuit determines at least one of a flow rate, an opening area, or a confidence index, and the processor circuit outputs a graphical representation based on at least one of the flow rate, the opening area, or the confidence index to the display.

[0013] According to an exemplary aspect, an ultrasound system is provided that includes a processor circuit in communication with an array of acoustic elements and a display, the processor circuit performing the following operations: receiving ultrasound data acquired by the array of acoustic elements, the ultrasound data representing mitral regurgitation associated with an opening of a mitral valve, identifying an opening in an anatomical model of the mitral valve based on the ultrasound data, outputting a first graphical representation of the opening, modifying at least one of a shape, a position, or an orientation of the opening based on a comparison between the model of mitral regurgitation and the ultrasound data, and outputting a second graphical representation of the opening having at least one of the modified shape, modified position, or modified orientation.

[0014] In some embodiments of any one of the aspects of the invention, the ultrasound data includes Doppler data, and the processor circuit identifies an opening in the anatomical model of the mitral valve based on the Doppler data. In some aspects, the processor circuit identifies the opening based on a velocity in the Doppler data that exceeds a threshold velocity. In some aspects, the processor circuit modifies a shape of the opening by modifying the threshold velocity. In some aspects, the processor circuit modifies a position of the opening by moving the opening along a vertical direction in the anatomical model of the mitral valve. In some aspects, the processor circuit generates a model of the mitral regurgitation based on the opening. In some aspects, the ultrasound data includes Doppler data, and the processor circuit modifies at least one of a shape, a position, or an orientation of the opening based on a comparison between the model of the mitral regurgitation and the Doppler data. In some aspects, the processor circuit generates a further model of the mitral regurgitation based on the opening having at least one of a modified shape, a modified position, or a modified orientation. In some aspects, the processor circuit outputs a 3D iso-velocity surface based on the model of the mitral regurgitation. In some aspects, the processor circuit outputs a first ultrasound image based on the ultrasound data and a second ultrasound image based on the ultrasound data, the first ultrasound image having an orientation along a first axis and the second ultrasound image having an orientation along a different second axis. In some aspects, the first ultrasound image and the second ultrasound image are based on multiplanar reconstruction (MPR). In some aspects, the first ultrasound image and the second ultrasound image include a side view. In some aspects, the first axis and the second axis correspond to at least one of a shape or a modified shape of the opening. In some aspects, the processor circuit determines at least one of a flow rate, an opening area, or a confidence index, and the processor circuit outputs a graphical representation based on at least one of the flow rate, the opening area, or a confidence index to a display.

[0015] According to one exemplary aspect, an ultrasound system is provided that includes a processor circuit in communication with an array of acoustic elements and a display, the processor circuit being operable to: receive Doppler ultrasound data acquired by the array of acoustic elements, the Doppler ultrasound data being indicative of mitral regurgitation associated with a mitral valve opening; generate a model of the mitral regurgitation based on the model of the opening; and output a screen display on the display, the screen display including a first ultrasound image including the Doppler ultrasound data and a graphical representation of the model of mitral regurgitation superimposed on the first ultrasound image such that the model of mitral regurgitation corresponds to the Doppler ultrasound data.

[0016] In some aspects, the graphical representation of the model of mitral regurgitation includes a graphical representation of a regurgitant flow distribution. In some aspects, the first ultrasound image includes a two-dimensional (2D) image, and the graphical representation of the regurgitant flow distribution includes iso-velocity lines. In some aspects, the first ultrasound image includes a three-dimensional (3D) image, and the graphical representation of the regurgitant flow distribution includes a iso-velocity mesh. In some aspects, the graphical representation of the model of mitral regurgitation includes a graphical representation of a regurgitant flow field. In some aspects, the graphical representation of the regurgitant flow field includes vectors. In some aspects, the graphical representation of the model includes a graphical representation of an axis of a mitral regurgitant flow jet. In some aspects, the graphical representation of the model includes a graphical representation of an axis perpendicular to the mitral valve. In some aspects, the screen display includes a second ultrasound image, the first ultrasound image having an orientation along a first axis and the second ultrasound image having an orientation along a different second axis. In some aspects, the first ultrasound image and the second ultrasound image include a side view. In some aspects, the first axis and the second axis correspond to a shape of the orifice. In some aspects, the graphical representation of the model includes a graphical representation of an orifice contour. In some aspects, the first ultrasound image includes a top view. In some aspects, the screen display further includes a three-dimensional (3D) representation of the model of mitral regurgitation.

[0017] According to an exemplary aspect, an ultrasound system is provided, the ultrasound system including an array of acoustic elements for acquiring ultrasound data including Doppler data and B-mode data, and a processor circuit in communication with the array of acoustic elements and a display, the processor circuit performs the following operations: receiving ultrasound data acquired by the array of acoustic elements, the ultrasound data representing mitral regurgitation associated with an opening of a mitral valve; generating a model of the mitral valve; generating a model of an opening based on the model of the mitral valve and the Doppler data; generating a blood flow model of the mitral regurgitation based on the model of the opening; comparing the blood flow model to the Doppler data; modifying the model of the opening such that the blood flow model is modified to match the Doppler data; calculating at least one of blood flow or opening area based on at least one of the blood flow model or the model of the opening; and outputting a screen display on the display, the screen display being based on two or more of the ultrasound data, the model of the mitral valve, the model of the opening, the blood flow model, the blood flow, or the opening area.

[0018] Further aspects, features, and advantages of the present disclosure will become apparent from the following detailed description. [Brief description of the drawings]

[0019] Illustrative embodiments of the present disclosure will now be described in conjunction with the accompanying drawings, in which:

[0020] [Figure 1] FIG. 1 shows a schematic diagram of an ultrasound imaging system according to an aspect of the present disclosure. [Diagram 2] FIG. 2 is a schematic diagram of a processor circuit according to an aspect of the present disclosure. [Diagram 3] FIG. 3 illustrates a flow diagram of a method for measuring mitral regurgitation according to an aspect of the present disclosure. [Figure 4] FIG. 4 is a schematic diagram of a cross section of a three-dimensional color Doppler ultrasound image according to an aspect of the present disclosure. [Diagram 5] FIG. 5 is a schematic diagram of a series of ultrasound images received by an ultrasound imaging system according to an aspect of the present disclosure. [Figure 6] FIG. 6 is a schematic diagram of a model of a mitral valve in accordance with aspects of the present disclosure. [Figure 7] FIG. 7 is a cross-sectional view of a three-dimensional color Doppler ultrasound image of the mitral valve during systole, according to an aspect of the present disclosure. [Figure 8A] FIG. 8A is a schematic diagram of flow through two holes in a plane according to an aspect of the present disclosure. [Figure 8B] FIG. 8B is a schematic diagram of flow through two holes in a plane according to an aspect of the present disclosure. [Figure 9A] FIG. 9A is a schematic diagram of flow through two holes in a plane according to an aspect of the present disclosure. [Figure 9B] FIG. 9B is a schematic diagram of flow through two holes in a plane according to an aspect of the present disclosure. [Figure 10] FIG. 10 is a schematic diagram of a model of the mitral valve orifice in accordance with aspects of the present disclosure. [Figure 11A] FIG. 11A is a schematic diagram of a model of the mitral valve, upstream blood flow, and downstream blood flow according to aspects of the present disclosure. [Figure 11B] FIG. 11B is a schematic diagram of a model of the mitral valve, upstream blood flow, and downstream blood flow according to aspects of the present disclosure. [Figure 12] FIG. 12 is a schematic diagram of virtual three-dimensional Doppler volume data corresponding to a model of the mitral valve according to an aspect of the present disclosure. [Figure 13] FIG. 13 is a schematic diagram illustrating a comparison of virtual and acquired three-dimensional Doppler volume data according to an aspect of the present disclosure. [Figure 14] FIG. 14 is a schematic diagram of virtual three-dimensional Doppler volume data corresponding to a model of the mitral valve according to an aspect of the present disclosure. [Figure 15] FIG. 15 is a schematic diagram illustrating a comparison of virtual and acquired three-dimensional Doppler volume data according to an aspect of the present disclosure. [Figure 16] FIG. 16 is a schematic diagram of a comparison of a model of blood flow data and acquired blood flow data before adjustment of the model, according to an aspect of the present disclosure. [Figure 17] FIG. 17 is a schematic diagram of a comparison of model and acquired blood flow data after adjustment of the model, according to an aspect of the present disclosure. [Figure 18] FIG. 18 is a schematic diagram of a model of the mitral valve opening after velocity threshold adjustment in accordance with aspects of the present disclosure. [Figure 19] FIG. 19 is a schematic diagram of a graphical user interface displaying an image and associated indicia according to an aspect of the present disclosure. [Figure 20] FIG. 20 is a schematic diagram of modeled and adjusted blood flow data overlaid on a cross-section of a three-dimensional color Doppler ultrasound image according to an aspect of the present disclosure. [Figure 21] FIG. 21 is a schematic diagram of modeled and adjusted blood flow data overlaid on a cross-section of a three-dimensional color Doppler ultrasound image according to an aspect of the present disclosure. [Figure 22] FIG. 22 is a schematic diagram of a graph displaying measurements of volumetric regurgitant volume and orifice area throughout the systolic phase of the cardiac cycle, according to an aspect of the present disclosure. [Figure 23A] FIG. 23A shows a schematic diagram of a blood flow model according to an aspect of the present disclosure. [Figure 23B] FIG. 23B shows a schematic diagram of a blood flow model according to an aspect of the present disclosure. [Figure 24] FIG. 24 is a schematic diagram comparing a blood flow model generated using a computational fluid dynamics technique with a blood flow model generated using a hole geometry flow model according to aspects of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] In order to facilitate the understanding of the principles of the present disclosure, reference will be made to the illustrated embodiments and specific terms will be used to describe them. However, it will be understood that this is not intended to limit the scope of the present disclosure. Any changes and modifications to the described apparatus, system, method, and further applications of the principles of the present disclosure are fully considered and included in the present disclosure, as would normally occur to a person skilled in the art to which the present disclosure pertains. In particular, it is fully considered that the features, components, and / or steps described with respect to one embodiment may be combined with the features, components, and / or steps described with respect to other embodiments of the present disclosure. However, for the sake of brevity, such multiple combinations of repetitions will not be described separately.

[0022] The present disclosure describes a processor circuit that can detect a 3D opening in a 3D anatomical model of a valve. The 3D anatomical model of the valve can be generated based on ultrasound data (e.g., B-mode ultrasound data) acquired by an acoustic element of an ultrasound imaging device. The processor circuit uses the 3D anatomical model of the valve to initiate a first determination (e.g., shape, location, and / or orientation) of the opening. The detected 3D opening in the 3D model of the valve can be output to a display. Based on the initial detection of the shape, location, and / or orientation of the opening in the valve model, the processor circuit can calculate a regurgitant flow (e.g., a shape of the regurgitant flow) associated with the opening. For example, the calculated regurgitant flow represents blood flow upstream of the opening. The processor circuit can compare the calculated regurgitant flow to the 3D Doppler ultrasound data. For example, the calculated regurgitant flow is compared to a portion of the 3D Doppler ultrasound data upstream of the opening. The first determination of the opening in the valve model can be adjusted based on this comparison. For example, the shape, location, and / or orientation of the opening in the valve model can be changed. The regurgitation may then be recalculated using the new shape, location, and / or orientation of the opening. This updated regurgitation may be compared to the 3D Doppler ultrasound data to assess whether there is a better match / correspondence, indicating that the new shape, location, and / or orientation of the opening in the valve more accurately represents the actual opening in the patient's valve. The processor circuitry may repeat these steps (changing the opening in the valve model, recalculating the regurgitation, and comparing the regurgitation model to the 3D Doppler ultrasound data) until the processor circuitry determines a suitable match with the acquired 3D Doppler ultrasound data. The processor circuitry may perform all of the above steps for each frame of the 3D Doppler ultrasound data over time. The processor circuitry may also output an indication of the calculated regurgitation and / or opening on an ultrasound image generated based on the 3D Doppler ultrasound data.

[0023] In some embodiments, aspects of the present disclosure may include features similar to those described in International Publication WO2020164955, "Methods and Systems for Valve Regurgitation Assessment," filed February 4, 2020, which is incorporated by reference in its entirety.

[0024] 1 shows a schematic diagram of an ultrasound imaging system 100 according to an aspect of the present disclosure. The system 100 is used to scan an area or volume of a patient's body. The system 100 includes an ultrasound imaging probe 110 in communication with a host 130 via a communication interface or link 120. The probe 110 may include a transducer array 112, a beamformer 114, a processor circuit 116, and a communication interface 118. The host 130 may include a display 132, a processor circuit 134, and a communication interface 136.

[0025] The probe 110 may have any suitable form suitable for any suitable ultrasound imaging application, including both external and internal ultrasound imaging. In some embodiments, the probe 110 is an external ultrasound imaging device that includes a housing configured for handheld operation by a user. The transducer array 112 may be configured to acquire ultrasound data while a user holds the housing of the probe 110 such that the transducer array 112 is positioned adjacent to and / or in contact with the patient's skin. The probe 110 is configured to acquire ultrasound data of an internal anatomical structure of a patient while the probe 110 is positioned outside the patient's body. In some embodiments, the probe 110 may be an external ultrasound probe, such as a transthoracic echocardiography (TTE) probe.

[0026] In other embodiments, the probe 110 may be an internal ultrasound imaging device and may include a housing configured to be placed within a lumen of the patient's body, including the patient's esophagus, a heart chamber, the coronary vasculature, the peripheral vasculature, or other body cavity. In some embodiments, the probe 110 may be an intravascular ultrasound (IVUS) imaging catheter, or an intracardiac echocardiography (ICE) catheter. In other embodiments, the probe 110 may be a transesophageal echocardiography (TEE) probe.

[0027] The transducer array 112 emits ultrasound signals toward an anatomical object 105 of the patient and receives echo signals that are reflected from the object 105 back to the transducer array 112. The ultrasound transducer array 112 can include any suitable number of acoustic elements, including one or more acoustic elements and / or multiple acoustic elements. In some cases, the transducer array 112 includes a single acoustic element. In some cases, the transducer array 112 can include an acoustic element array having any number of acoustic elements in any suitable configuration. For example, the transducer array 112 can include between 1 and 10,000 acoustic elements, such as 2, 4, 36, 64, 128, 500, 712, 1,000, 3,000, 7,000, and / or more or less acoustic elements. In some cases, the transducer array 112 may include an acoustic element array having any number of acoustic elements in any suitable configuration, such as a linear array, a planar array, a curved array, a curvilinear array, a circumferential array, an annular array, a phased array, a matrix array, a one-dimensional (1D) array, a 1.x-dimensional array (e.g., a 1.5D array), or a two-dimensional (2D) array. The acoustic element array (e.g., one or more rows, one or more columns, and / or one or more orientations) may be controlled and actuated uniformly or independently. The transducer array 112 may be configured to acquire one-dimensional, two-dimensional, and / or three-dimensional images of the patient's anatomy. In some embodiments, the transducer array 112 may include piezoelectric micromachined ultrasound transducers (PMUTs), capacitive micromachined ultrasonic transducers (CMUTs), single crystal, lead zirconate titanate (PZT), PZT composites, other suitable transducer types, and / or combinations thereof.

[0028] The object 105 may include any anatomical structure, such as the patient's blood vessels, nerve fibers, airways, mitral valve leaflets, cardiac structures, abdominal tissue structures, appendix, large intestine (or colon), small intestine, kidneys, liver, and / or any other anatomical structure. In some aspects, the object 105 may include at least a portion of the patient's large intestine, small intestine, cecal pouch, appendix, terminal ileum, liver, epigastric region, and / or psoas muscle. The present disclosure may be implemented in connection with any number of anatomical locations and tissue types, including non-limiting examples of organs including liver, heart, kidneys, gallbladder, pancreas, lungs; ducts; intestines; nervous system structures including brain, dural sac, spinal cord, and peripheral nerves; valves in the urinary tract, blood vessels, blood, ventricles, or other parts of the heart, abdominal organs, and / or other systems of the body. In some embodiments, the object 105 may include malignancies such as tumors, cysts, lesions, hemorrhages, or blood pools in any part of the human anatomy. The anatomical structure may be a blood vessel, such as an artery or vein, of the patient's vascular system, including, for example, the cardiovascular system, the peripheral vascular system, the neurovascular system, the renal vascular system, and any other suitable lumen in the body. The anatomical object 105 may further include a ventricle or an atrium. In addition to natural structures, the present disclosure may be implemented in connection with artificial structures, such as, but not limited to, heart valves, stents, shunts, filters, implants, and other devices.

[0029] The beamformer 114 is coupled to the transducer array 112. The beamformer 114 controls the transducer array 112, for example, to transmit ultrasound signals and receive ultrasound echo signals. In some embodiments, the beamformer 114 can apply time delays to signals sent to individual acoustic transducers in the array of transducers 112 so that the acoustic signals are directed in any suitable direction propagating from the probe 110. The beamformer 114 can further provide image signals to the processor circuit 116 based on the response of the received ultrasound echo signals. The beamformer 114 can include multiple stages of beamforming. The beamforming can reduce the number of signal lines for coupling to the processor circuit 116. In some embodiments, the combination of the transducer array 112 and the beamformer 114 can be referred to as an ultrasound imaging component.

[0030] The processor circuit 116 is coupled to the beamformer 114. The processor circuit 116 may also be described as a processor circuit or a processor. The processor circuit 116 may include a central processing unit (CPU), a graphical processing unit (GPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, other hardware devices, firmware devices, or any combination thereof configured to perform the operations described herein. The processor circuit 134 may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in combination with a DSP core, or other similar configurations. The processor circuit 116 is configured to process the beamformed image signal. For example, the processor circuit 116 may perform filtering and / or quadrature demodulation to condition the image signal. The processor circuit 116 and / or 134 may be configured to control the array 112 to acquire ultrasound data associated with the object 105.

[0031] The communications interface 118 is coupled to the processor circuitry 116. The communications interface 118 may include one or more transmitters, one or more receivers, one or more transceivers, and / or circuitry for transmitting and / or receiving communication signals. The communications interface 118 may include hardware and / or software components that implement a particular communications protocol suitable for transmitting signals to the host 130 over the communications link 120. The communications interface 118 may also be referred to as a communications device or a communications interface module.

[0032] Communications link 120 may be any suitable communications link. For example, communications link 120 may be a wired link, such as a universal serial bus (USB) link or an Ethernet link. Alternatively, communications link 120 may be a wireless link, such as an ultra-wideband (UWB) link, an Institute of Electrical and Electronics Engineers (IEEE) 802.11 WiFi link, or a Bluetooth link.

[0033] In the host 130, a communication interface 136 may receive the image signal. The communication interface 136 may be substantially similar to the communication interface 118. The host 130 may be any suitable computing and display device, such as, for example, a workstation, a personal computer (PC), a laptop, a tablet, or a mobile phone.

[0034] The processor circuit 134 is coupled to the communication interface 136. The processor circuit 134 may be implemented as a combination of software and hardware components. The processor circuit 134 may include a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, an FPGA device, other hardware devices, firmware devices, or any combination thereof configured to perform the operations described herein. The processor circuit 134 may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in combination with a DSP core, or other similar configurations. The processor circuit 134 may be configured to generate image data from image signals received from the probe 110. The processor circuit 134 may apply advanced signal processing and / or image processing techniques to the image signals. In some embodiments, the processor circuit 134 may form a three-dimensional (3D) volumetric image from the image data. In some embodiments, the processor circuitry 134 may perform real-time processing on the image data to provide streaming video of ultrasound images of the object 105. In some aspects, the processor circuitry 134 may also perform various calculations related to regions of interest within the patient's body. These calculations may then be displayed to the sonographer or other user via the display 132.

[0035] The display 132 is coupled to the processor circuit 134. The display 132 may be a monitor or any suitable display. The display 132 is configured to display ultrasound images, image videos, and / or any imaging information of the object 105.

[0036] The host 130 may include memory 138, which may be any suitable storage device, such as cache memory (e.g., cache memory of the processor circuitry 134), random access memory (RAM), magnetoresistive RAM (MRAM), read only memory (ROM), programmable read-only memory (PROM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), flash memory, solid state memory devices, hard disk drives, solid state drives, other forms of volatile and non-volatile memory, or combinations of various types of memory. The memory 138 may be configured to store patient files relating to the patient's medical history, history of procedures performed, anatomical or biological features, characteristics, or medical conditions associated with the patient, computer readable instructions such as code, software, or other applications, and other suitable information or data.

[0037] 2 is a schematic diagram of a processor circuit according to an aspect of the disclosure. The processor circuit 210 may be implemented in the processing system 106 of FIG. 1. In an example, the processor circuit 210 may communicate with the endoluminal imaging device 102, the X-ray imaging system 109, and / or the display 108 in the system 100. The processor circuit 210 may include a processor and / or a communication interface. One or more processor circuits 210 are configured to perform the operations described herein. As shown, the processor circuit 210 may include a processor 260, a memory 264, and a communication module 268. These elements may communicate with each other directly or indirectly, for example, via one or more buses.

[0038] Processor 260 may include a CPU, GPU, DSP, application-specific integrated circuit (ASIC), controller, FPGA, other hardware device, firmware device, or any combination thereof configured to perform the operations described herein. Processor 260 may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in combination with a DSP core, or other similar configurations.

[0039] The memory 264 may include cache memory (e.g., cache memory of the processor 260), random access memory (RAM), magnetoresistive RAM (MRAM), read only memory (ROM), programmable read-only memory (PROM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), flash memory, solid state memory devices, hard disk drives, other forms of volatile and non-volatile memory, or a combination of various types of memory. In one example, the memory 264 includes a non-transitory computer readable medium. The memory 264 may store instructions 266. The instructions 266 may include instructions that, when executed by the processor 260, cause the processor 260 to perform the operations described herein with reference to the probe 110 and / or the processing system 106 (FIG. 1). The instructions 266 may also be referred to as code. The terms "instructions" and "code" should be interpreted broadly to include any type of computer readable statement. For example, the terms "instructions" and "code" may refer to one or more programs, routines, subroutines, functions, procedures, etc. "Instructions" and "code" may include a single computer-readable statement or multiple computer-readable statements.

[0040] The communication module 268 may include any electronic and / or logic circuitry that facilitates direct or indirect data communication between the processor circuit 210, the probe 110, and / or the display or monitor 108. In this regard, the communication module 268 may be an input / output (I / O) device. In some cases, the communication module 268 facilitates direct or indirect communication between various elements of the processor circuit 210 and / or the probe 110 (FIG. 1) and / or the system 106 (FIG. 1). For example, the processor circuit 210 may communicate with the probe 110, the transducer 112 or array 112, and / or the display 132.

[0041] FIG. 3 illustrates a flow diagram of a method for measuring mitral regurgitation according to aspects of the present disclosure. Method 300 is described with reference to FIGS. 4-22. As illustrated, method 300 includes a number of recited steps, but embodiments of method 300 may include additional steps before, after, or between the recited steps. In some embodiments, one or more of the recited steps may be omitted, performed in a different order, or performed simultaneously. The steps of method 300 may be performed by any suitable component in system 100, and not all steps need to be performed by the same component. In some embodiments, one or more steps of method 300 may be performed by or under the direction of a processor circuit (e.g., processor circuit 210 of FIG. 2) of system 100, including, for example, processor 260 or any other components.

[0042] In step 305, the method 300 includes acquiring three-dimensional (3D) Doppler volume data of the mitral valve over time. The 3D Doppler volume data may be referred to as 3D color Doppler data, color Doppler data, 3D color Doppler time series, or any other suitable term. The 3D ultrasound data over time may also be referred to as 4D ultrasound data having three spatial dimensions and time as the fourth dimension. The 3D Doppler volume data may have any suitable format. In some embodiments, the 3D Doppler volume data may be a color 3D Doppler image as shown in FIG. 4. In some embodiments, the system 100 may also receive 2D or 3D B-mode ultrasound data in addition to the Doppler data throughout the imaging procedure, also as shown in FIG. 4. For example, the Doppler data acquisition and the B-mode data acquisition may be interleaved and acquired over the same time period. Any of this data may be received by the processor circuit 210 (FIG. 2). FIG 4 is a schematic diagram of a cross-section of a three-dimensional color Doppler ultrasound image 400 according to an aspect of the present disclosure. The image 400 shown in FIG 4 may be acquired by the probe 110 of the ultrasound system 100 during an ultrasound imaging procedure. The image 400, or other images acquired during such a procedure, may show various anatomical structures of a patient's heart. For example, the image 400 of FIG 4 shows a cross-sectional side view of the mitral valve 430 within the patient's heart.

[0043] The image 400 may show various features of the patient's heart. For example, the image 400 may show a left ventricle 420 and a left atrium 410 separated by a mitral valve 430. During the cardiac phase, systole, the mitral valve 430 closes, increasing pressure within the left ventricle 420 and moving blood from the left ventricle 420 to the aorta and to other parts of the patient's body. If the mitral valve 430 does not close completely during systole, blood may flow backward from the left ventricle 420 into the left atrium 410, reducing the efficiency of the heart. This backward flow of blood is seen in the image 400 and regurgitation 440. This backward flow 440 may be referred to as a jet, regurgitation, or any other suitable term. The method 300 described herein advantageously provides an accurate and efficient way of quantifying this backward flow 440.

[0044] Referring again to Figure 3, at step 310, the method 310 includes identifying a frame of 3D Doppler volume data that corresponds to a systolic phase of the cardiac cycle. As noted above, regurgitation 440, as described with reference to Figure 4, occurs during the systolic phase of the cardiac cycle. To identify frames in which mitral regurgitation may occur, it is necessary to identify all ultrasound image frames that show the mitral valve during systole. Step 310 will now be described with reference to Figure 5, which is a schematic illustration of a series of ultrasound images 510 received by an ultrasound imaging system according to an aspect of the present disclosure.

[0045] In Figure 5, a series of ultrasound images 510 are shown in chronological order. For example, ultrasound image 512 may be the first acquired ultrasound image of the multiple images 510 shown in Figure 5. Similarly, image 518 may be the last acquired ultrasound image of the images 510 shown in Figure 5. This temporal relationship between the images 510 is further indicated by arrows 590, which indicate that the position of each image 510 corresponds to the relative time that the image 510 was acquired. This indicates that the images in the left portion of Figure 5 were acquired earlier and time progresses to the right, thus indicating that the images 510 in the right portion of Figure 5 were acquired later.

[0046] The image 510 identified by indicator 520 may correspond to an ultrasound image showing the mitral valve 430 (FIG. 4) acquired during diastole. In contrast, the image 510 identified by indicator 530 may correspond to an ultrasound image acquired during systole. And finally, the image 510 identified by indicator 540 may correspond to an image acquired during diastole. In step 310, the image indicated by indicator 530 may be identified.

[0047] The ultrasound image 510 indicated by indicator 530 may be identified by any suitable method. For example, a user of system 100 may identify the image indicated by indicator 530 that corresponds to a systole phase. In such an embodiment, system 100 may display images 510 to the user in succession. System 100 may then receive input from the user identifying an image 514 where systole begins. Similarly, the system may receive user input identifying an image 516 where diastole begins following systole.

[0048] Alternatively, the system 100 may automatically identify ultrasound images 510 corresponding to systole as indicated by the indicator 530. The system 100 may identify these images 510 by any suitable method. In some embodiments, the processor circuit may receive user input identifying a systolic frame manually provided by a user at a user interface device in communication with the processor circuit. In some embodiments, the processor circuit may execute software such as 4D MV-Assessment software available from TomTec to acquire the systolic portion of the acquisition. In some embodiments, the system 100 may use various image processing techniques to determine that the mitral valve 430 (FIG. 4) has closed. These techniques may include edge identification, pixel-by-pixel analysis to determine transitions between light and dark pixels, filtering, or other suitable techniques for identifying relevant structures or locations within the received image frames. The system 100 may also use various machine learning techniques to recognize ultrasound image frames 512 where the mitral valve has closed and systole has begun.

[0049] Similar image processing or machine learning techniques can be used to identify the image frame 516 where systole ends and diastole begins. For example, the system 100 can determine that the aortic valve of the heart is closing, signaling the end of systole.

[0050] Referring again to FIG. 3, step 315 of method 300 includes identifying a first ultrasound image 512 in systole identified in step 310 and indicated by indicator 530 in FIG. 5. This first ultrasound image 512 may be designated to correspond to an iteration counter n. For example, for the first ultrasound image 512 in systole, system 100 may assign an iteration counter n=0. As described in more detail in the description of step 355, each step of steps 320-345 may be completed for each ultrasound image 510 indicative of the systole portion of a cardiac phase. Upon completion of steps 320-345, the iteration counter n may be incremented by 1, so that the system may perform steps 320-345 using the ultrasound image 510 acquired next in time in the set of images corresponding to systole.

[0051] In step 320, the method 300 includes generating a 3D model of the mitral valve shown in the selected image 510. Step 320 of the method 300 is described with reference to FIG. 6, which is an illustration of an imaginary valve model 630 according to an aspect of the present disclosure. The model of the mitral valve may be generated by any suitable method. For example, the processor circuit 210 may be configured to generate a model of the mitral valve based on the ultrasound data acquired in step 305 of the method 300. In this regard, the anatomical model of the mitral valve may be extracted from B-mode ultrasound data. The model of the mitral valve may be three-dimensional or two-dimensional. The model of the mitral valve may be referred to as a dynamic model in that the model is generated over time as it is generated for each image frame of the 3D ultrasound data. For example, the model may be generated by defining a mesh corresponding to the surface of the valve. The generation of the 3D model of one or more regions of the heart, such as the mitral valve, may include several features similar to those described in U.S. Pat. No. 10,729,406, the entirety of which is incorporated herein by reference. In some embodiments, utilizing a model of the mitral valve advantageously avoids identifying the mitral valve in the 3D ultrasound data by user input, which may be subject to user error and / or inexperience. In step 320, in some embodiments, the model may be generated automatically without user input.

[0052] As shown by axis 690 in FIG. 6, model 630 of the mitral valve is three-dimensional. In some embodiments, the model of the mitral valve may be referred to as a structural model, a geometric model, or a spatial model. Current methods of estimating regurgitant flow through the mitral valve assume that the mitral valve behaves as an infinite two-dimensional plane. However, the mitral valves of various patients are neither infinite nor two-dimensional. Rather, as shown by model 630 in FIG. 6, the mitral valve contains irregularities in three dimensions, terminating at the walls of the left ventricle and / or atrium. The three-dimensional model 630 disclosed herein more accurately reflects the actual geometry of the mitral valve, which results in a more accurate measurement of regurgitant flow. In this regard, the orifice is described as a collection of points / small orifices (e.g., source points) located on the three-dimensional mitral valve model. For each of these points / small orifices, the associated flow model is a three-dimensional flow field, and the complete flow model is the convolution of this flow model with all the source points. As a result of the three-dimensional location of these source points (and the fact that they do not lie on a plane as in the PISA approximation), the flow model resulting from the convolution is much more complex, and gives a much better estimate of the actual flow field.

[0053] Referring again to FIG. 3, step 325 of method 300 includes defining a 3D opening in the 3D mitral valve model. In this regard, the 3D opening may be defined (e.g., shape, location, and / or orientation) in the 3D mitral valve model. For example, the 3D opening model may be part of the 3D mitral valve model. In some embodiments, the size, shape, and location of the opening need to be determined in order to accurately model the upstream and downstream blood flow through the opening of a leaking mitral valve. The opening of the mitral valve may have a complex shape, e.g., slit-like, circular, non-circular, or any other shape. Furthermore, one or more openings may occur due to the mitral valve not closing completely. The principles described with reference to step 325 account for all of these types of openings, as described below. For example, the processor circuitry may generate a 3D or 2D model of the mitral valve and / or opening. Step 325 is described with reference to FIG. 7. FIG. 7 is a cross-sectional view of a three-dimensional color Doppler ultrasound image of a mitral valve during systole, according to aspects of the present disclosure. The model of the orifice may be referred to as a dynamic model in that the model is generated over time as it is generated for each image frame of the 3D ultrasound data. In some embodiments, for example to define the orifice, the method 300 utilizes a model of the mitral valve, thereby avoiding registration of the valve and / or orifice over time in the 3D Doppler ultrasound images. Advantageously, this eliminates image stabilization, image segmentation, image registration, and / or image tracking steps over time associated with the mitral valve and / or orifice in the 3D Doppler ultrasound images that may be required without the use of a 3D mitral valve model. The use of the 3D mitral valve model and extraction of the orifice from the 3D mitral valve model provides a more accurate shape of the orifice that can be used to determine the regurgitation model, as described below. The 3D mitral valve model can be automatically tracked using 4D MV-Assessment software available from TomTec.

[0054] The image 700 shown in FIG. 7 may display a top view of the mitral valve. For example, a view of the mitral valve from within the left atrium. From this perspective, if the mitral valve is leaking or allowing blood to flow back from the ventricle to the atrium during systole, the 3D color Doppler data may identify such blood movement. Specifically, areas of higher blood flow velocity may correspond to areas of the mitral valve opening or aperture that are allowing blood to flow from the ventricle to the atrium. Thus, the opening in the 3D model of the valve can be determined using the color Doppler ultrasound data, while the 3D model of the valve itself is determined from the B-mode ultrasound data. Both the color Doppler ultrasound data and the B-mode ultrasound data may be acquired in the 3D Doppler volume data over time from step 305.

[0055] To determine which regions of image 700 correspond to an opening and which correspond to the mitral valve, the measured velocity of each portion of the image may be compared to a velocity threshold. Sections of the image that exhibit velocities that exceed the velocity threshold may be classified as part of the opening, while sections that do not meet or exceed the velocity threshold are classified as part of the mitral valve. As shown in image 700, regions of blood flow that exceed the velocity threshold may be identified by an indicator 742 that outlines the location of the opening. Color data 730 within indicator 742 indicates velocities that exceed the threshold velocity.

[0056] In some embodiments, the processor circuitry can automatically identify the opening location and / or opening boundary by calculating a minimum area of ​​ultrasound color suction blood flow. In some embodiments, the system 100 can identify the location of the mitral valve opening in response to a user input. For example, a user can identify an area of ​​the image 700 that corresponds to the mitral valve opening. In some embodiments, the user can select any location within the area that indicates the opening, as indicated by indicator 742, and the system 100 can automatically identify the opening and generate indicator 742 accordingly. The system can identify the opening area by the velocity threshold method described above, or by other methods, such as the image processing or machine learning techniques described above. The mitral valve opening may also be referred to as an annulus. The identified opening 742 may also be referred to as a model. For example, the opening contour shown in FIG. 7 may be a model generated by the processor circuitry 210 (FIG. 2) of the opening. The opening model may be two-dimensional or three-dimensional. The opening model may also be referred to as a structural model, a geometric model, or a spatial model. The model of the orifice may be generated based on a model of the mitral valve (FIG. 6) and / or B-mode or Doppler data acquired in step 305 of method 300 (FIG. 3).

[0057] Referring again to FIG. 3, in step 330, the method 300 includes modeling blood flow through a three-dimensional opening based on the shape of the opening. In some embodiments, the opening is part of a 3D mitral valve model, so that blood flow through the opening may also be based on the shape of the 3D mitral valve. The blood flow model may be three-dimensional. Step 330 is described with reference to FIGS. 8-12. To model blood flow through the opening of the mitral valve during systole, the opening may be defined as a combination of multiple source points distributed on the opening surface. Because the flow of fluid through a single source point can be easily and accurately determined, modeled, and measured, convolution of the flow calculated from multiple source points located adjacent to each other allows the system to accurately determine the flow through more complex openings, such as the opening of the mitral valve. This principle is described in more detail below with reference to FIGS. 8A, 8B, 9A, and 9B. The model of the mitral valve, the opening, and the blood flow upstream of the opening is a new descriptor for mitral regurgitation assessment, extracting the morphology and dynamics of the regurgitation, resulting in more accurate quantification.

[0058] 8A is a diagram of flow through two holes in a plane according to aspects of the present disclosure. As an example, plane 810 is provided. Plane 810 may be a two-dimensional infinite plane. Plane 810 may be oriented to extend infinitely along an x-axis and a y-axis, as shown by axis 890. An additional x-axis may extend in a direction perpendicular to both the x-axis and the y-axis, as will be described in more detail with reference to FIG. 8B.

[0059] Two holes or openings, hole 820 and hole 830, are disposed within a plane 810. A liquid, such as blood or other liquid, may pass from one side of the plane 810 to the other through the two holes 820 and 830. FIG. 8A shows constant velocity curves disposed around each of the holes 820 and 830. For example, constant velocity curve 822 and constant velocity curve 824 are disposed around hole 820. The constant velocity curves may represent the velocity of the fluid approaching and passing through the holes. For example, as the fluid approaches hole 820, the fluid may accelerate and reach a maximum velocity as it passes through hole 820. As a result, the fluid located at constant velocity curve 824 may have a constant velocity at all points along curve 824. Also, while curve 824 is shown as a two-dimensional curve along plane 810, the constant velocity curve is a three-dimensional hemispherical shell representing all points in the fluid surrounding hole 820 with the same velocity. Similarly, constant velocity curve 822 located around hole 820 may represent a three-dimensional hemispherical shell representing all points within the fluid surrounding hole 820 that have the same velocity, but because the fluid accelerates as it approaches hole 820, the velocity at the point represented by curve 822 may be higher than the velocity represented by curve 824.

[0060] If the radius 828, i.e., the distance from the constant velocity curve 822 to the center of the hole 820, is sought, the surface area of ​​the shell described by the curve 822 is 2πr 2 where r is the radius 828. Also, if the fluid velocity associated with constant velocity curve 822, i.e., the aliasing velocity, is known, then it can be multiplied with the surface area of ​​curve 822 to obtain a measure of the fluid flow through hole 820 as a volume per unit time. This same calculation can be performed with respect to curve 824 to obtain the same result. For a pinpoint source, the vector flow upstream of the opening towards that point is 1 / r 2 The flow field can then be derived from the velocity potential P, where

number

[0061] To apply this principle to irregular openings that are not a single source point, the openings can be modeled as multiple source points. For example, the flow model can be expressed as a result of the convolution of a point source distribution with a hemispherical solution. In some embodiments, to improve the speed and efficiency of the process, a scalar convolution can be used rather than a 3D vector convolution with the velocity potential. This velocity potential can then be differentiated to obtain the full vector field associated with the complex opening. For example, as shown in FIG. 8A, an additional hole 830 can be placed adjacent to hole 820. The fluid flow through these two holes can be very similar to the fluid flow through a small vertical slit of a similar shape to the two holes 820 and 830 shown in FIG. 8A. The same calculations can be performed for hole 830 to determine the flow through the two holes shown and / or through similar corresponding slits. For example, a constant velocity curve 832 is shown positioned around hole 830, and a constant velocity curve 834 is shown positioned around curve 832. Assuming that hole 830 has the same size and shape as hole 820, constant velocity curve 832 will be identical to constant velocity curve 822. Specifically, constant velocity curve 832 may represent a three-dimensional hemispherical shell representing all points in the fluid surrounding hole 830 with the same velocity. The velocity of the fluid along curve 832 may be identical to the velocity of the fluid along curve 822. Similarly, curve 834 may be identical to curve 824. As shown in FIG. 9A, the surface area, velocity, and flow rate calculations described for hole 820 can be determined for hole 830. The surface area, velocity, and flow rate calculations from both holes 820 and 830 can be convolved to generate a single model representing the surface area, velocity, and flow rate of the combined orifice backflow. The convolved flow model is calculated by combining the contributions of the two holes 820, 830. For example,

number

[0062] FIG. 8B is an illustration of flow through two holes in a plane according to aspects of the disclosure. As indicated by the zy axis 892, FIG. 8B may show the same plane 810, holes 820 and 830, and constant velocity curves 822, 824, 832 and 834 as described in FIG. 8A, but along a different axis. As shown in FIG. 8B, the constant velocity curves 822, 824, 832 and 834 extend along the z axis away from the plane of the plane 810. The constant velocity curves are observed upstream of the openings 820 and 830. As indicated by the arrows 850, the fluid in this example may flow from the left side of the plane 810 to the right side of the plane 810 as shown in FIG. 8B. In the example of a mitral valve, the region 860 upstream of the holes 820 and 830 where the constant velocity curves are observed may represent the left ventricle of the heart, and the region 870 downstream of the holes 820 and 830 may represent the left atrium.

[0063] FIG. 9A is an illustration of flow through two holes in a plane according to aspects of the disclosure. As shown in FIG. 9A and described above with reference to FIG. 8A, the flow models corresponding to holes 820 and 830, respectively, can be combined to generate a new flow model corresponding to treating both holes 820 and 830 as a single hole. This new flow model can then be used to determine constant velocity curves 922 and 924. Constant velocity curves 922 and 924 can exhibit similar characteristics to constant velocity curves 822, 824, 832, and 834 described with reference to FIGS. 8A and 8B. For example, constant velocity curve 922 can represent a three-dimensional shell surrounding the opening defined by holes 820 and 830, with fluid along the shell having the same velocity. Constant velocity curve 924 can also be a three-dimensional shell, with fluid along the three-dimensional shell having the same velocity, but at a slower velocity than curve 922.

[0064] By convolving the flow models for holes 820 and 830, a single model of the irregular opening that is more complex than a single point source can be created that accurately predicts fluid behavior. Based on this new model, the surface area of ​​various new constant velocity curves, such as curves 922 and 924, can be calculated, the fluid velocity can be determined, and the flow through the new complex openings can be accurately measured.

[0065] Figure 9B is a diagram of flow through two holes in a plane according to aspects of the present disclosure. Similar to Figure 8B, Figure 9B shows the same plane 810, holes 820 and 830, and constant velocity curves 922 and 924 as described in Figure 9A, but along a different axis, as indicated by zy-axis 892. The constant velocity curves 922 and 924 shown in Figure 9B extend along the z-axis upstream of the plane of plane 810.

[0066] FIG. 10 is a diagram of a model 1010 of a mitral valve orifice according to aspects of the disclosure. The model 1010 may be a two-dimensional model or a three-dimensional model. With reference to FIG. 3, in step 330, blood flow through a complex orifice of the mitral valve may be modeled using the principles described with reference to FIGS. 8A, 8B, 9A, and 9B. Specifically, the orifice may be divided into a number of single point sources arranged adjacent to each other. FIG. 10 shows a complex orifice modeled as a number of point sources 1020 arranged adjacent to each other in a grid. The model may include a number of points within the grid. The point sources that make up the grid of the model 1010 may be classified by the system 100 as valve points 1025 (i.e., points corresponding to the surface of the mitral valve) or orifice points 1020 (i.e., points corresponding to the orifice through which the retrograde flow of blood passes). For each orifice point 1020, a separate model may be determined that determines the surface area of ​​the iso-velocity curves, blood flow velocity, and flow. A convolution of all the models for each orifice point 1020 may then be performed to create a single model that represents the surface area, velocity, and flow throughout the orifice. The resulting model may be a blood flow model associated with mitral regurgitation through the orifice (e.g., the orifice defined by model 1010), or a model of blood flow. This blood flow model may be a fluid model or a fluid dynamics model and may include data such as iso-velocity curves, surfaces, or meshes, flow vectors, or any other indicators or data. The blood flow model generated as described with reference to FIG. 10 may be two-dimensional or three-dimensional. As described with reference to FIG. 10, the blood flow model generated may be generated based on an orifice model (e.g., model 742 in FIG. 7 or 1010 in FIG. 10). A single iso-velocity curve 1032 corresponding to this combined single model is shown in FIG. 10. The iso-velocity curve 1032 may represent points in three-dimensional space surrounding the indicated orifice where fluid moving toward the orifice moves at the same velocity. It will be appreciated that in addition to curve 1032, additional constant velocity curves may be included that represent locations of different velocities, surround curve 1032, or are within curve 1032.

[0067] In some embodiments, the processor circuitry can output a graphical representation of the initial opening model 1020. For example, a representation of the opening model 1020 may be provided within the valve model 1010 (e.g., as a graphical overlay). Such a representation may be associated with the vena contracta area (VCA) or vena contracta width (VCW), which is the narrowest area / width of the jet downstream of the opening. This may be a clinically significant area for the user that can be used to assess the severity of mitral regurgitation. In some embodiments, the graphical representation of the initial opening model 1020 and / or the valve model 1010 (e.g., as a graphical overlay) may be displayed on an ultrasound image generated using Doppler and / or B-model ultrasound data. The displayed initial opening model may be referred to as the VCA or VCW opening in some embodiments.

[0068] FIG. 11A is a diagram of a model 1110 of the mitral valve, upstream blood flow, and downstream blood flow according to aspects of the disclosure. FIG. 11A includes a depiction of the mitral valve 1130, an iso-velocity surface or mesh 1122 shown upstream of the mitral valve 1130, and a jet 1140 downstream of the mitral valve 1130. The jet 1140 may be detected using 3D segmentation of Doppler / color ultrasound data based on velocity thresholding. The model of the mitral valve 1130, the iso-velocity curve or surface 1122, and / or the jet 1140 may be two-dimensional or three-dimensional. For example, they may be displayed in two dimensions as a cross-section of a three-dimensional model, or they may be displayed in three dimensions. In some embodiments, the model of blood flow / mitral regurgitation is a fluid dynamics model, or a model of blood flow through a structural model of the valve and / or orifice.

[0069] The model 1110 may be constructed by the system 100 by combining a model of the mitral valve as shown in the ultrasound image frame 510 (FIG. 5) with a model of the orifice and blood flow as described with reference to FIG 10. For example, the isovelocity surface 1122 may be constructed using techniques similar to those described with respect to the isovelocity curve 1032 of FIG 10. The position of the isovelocity surface 1122 relative to the mitral valve 1130 may be determined based on the defined position and shape of the orifice in the mitral valve 1130 as described with reference to FIG 7.

[0070] FIG. 11A further includes an orientation axis 1190. In an embodiment where the model 1100 is displayed to a user of the system, the orientation axis 1190 may identify the jet's main axis of blood flow, the valve's normal axis, or the vertical axis. In some embodiments, the axis 1190 may identify the center point of the orifice, or any other feature of the mitral valve, orifice, or blood flow. In the illustrated embodiment, the axis 1190 is an axis associated with the jet 1140. For example, the axis 1190 may indicate the main direction of blood flow of the jet 1140. The processor circuitry can use the jet axis 1140 to automatically determine planar reformation or reconstruction viewing planes (MPR) and / or cutting planes for visualization. Clinically, the jet axis 1140 can be used by a physician to better understand the behavior of the blood flow.

[0071] FIG. 11B is an illustration of a model 1110 of the mitral valve, upstream blood flow, and downstream blood flow according to aspects of the present disclosure. As shown in FIG. 11B, the model 1100 may display the same mitral valve 1130, upstream iso-velocity surface 1122, jet 1140, and axis 1190 as shown in FIG. 11A. However, FIG. 11B may display these elements from a different perspective. As shown, the model 1100 may be a three-dimensional model that can be viewed from various angles or from various cut planes. For example, the processor circuitry may automatically rotate or display the 3D model 1100 (e.g., the model 1100 may be automatically rotated). In some embodiments, the model 1100 may rotate in response to a user input. For example, a user may instruct the system 100 to rotate the model 1100 via mouse input, use of an input button, touching a touch screen, or any other suitable form of input.

[0072] 12 is an illustration of virtual three-dimensional Doppler volume data corresponding to a model of the mitral valve according to aspects of the present disclosure. FIG. 12 may represent an alternative display format of the model and associated flow data described in FIG. 11. A virtual color image 1200 may be created by taking into account the scanning geometry and calculating the velocity components aligned with the beam direction. The velocity scale may be adjusted to closely match the color Doppler values. Flow may be calculated based on the vector field through the orifice.

[0073] As shown in Fig. 12, a model 1200 can be generated. The model 1200 can be two-dimensional or three-dimensional. The model 1200 includes a model of the mitral valve 1230, a section of the orifice 1242, and a virtual reconstruction of the generated 3D Doppler color data 1222. Also shown in Fig. 12 are two regions: an upstream region 1204 and a downstream region 1202. If the mitral valve allows regurgitation, the upstream region 1204 may correspond to the left ventricle and the downstream region 1202 may correspond to the left atrium.

[0074] The model of the mitral valve 1230 may be similar to the model 1130 described with reference to FIG. 11. It may be generated using the techniques described with reference to FIG. 6. An opening 1242 in the model 1230 is also shown, but may not be generated. The shape, size, and orientation of the opening 1242 may be determined using the techniques described with reference to FIG. 7. Based on the flow data calculated for the opening 1242 and the mitral valve 1230 (i.e., surface area, velocity, and flow measurements), virtual 3D color Doppler data 1222 may be generated and displayed. 3D color Doppler displays to the user of the system different colors corresponding to the velocity of objects in the acquired ultrasound image. Since the velocity of the fluid at all points in three dimensions upstream of the opening is known, different velocities may be assigned different colors to create the virtual 3D color Doppler data 1222, as shown in FIG. 12. In this regard, virtual may refer to a calculated value based on a calculated flow model. The creation of virtual 3D color Doppler data 1222 can be useful for validating model 1200 against actually acquired 3D color Doppler data corresponding to a patient's anatomy, as described in more detail in FIG. 13 .

[0075] Referring again to FIG. 3, at step 335, method 300 includes comparing blood flow based on the 3D model to acquired 3D Doppler volume data. Since the 3D Doppler volume data, or 3D color flow sequence, was acquired during the imaging procedure as in step 305, a model of the suction blood flow shape can be generated to fit the 3D color flow data by morphological detection of the opening. Aspects of step 335 are described with reference to FIGS. 13-15. FIG. 13 illustrates a comparison of virtual 3D Doppler volume data 1222 and acquired 3D Doppler volume data 1322, according to aspects of the present disclosure. FIG. 13 illustrates the same model 1200 with the virtual 3D Doppler volume 1222 overlaid on an ultrasound image 1300 with actual acquired 3D Doppler volume data 1322. FIG. 13 further illustrates a jet 1324 corresponding to downstream blood flow shown in image 1300. Viewing these 3D geometries (i.e., the upstream suction flow, the downstream jet, and the expanding opening) in three dimensions may reveal similarities between the internal flow model and the acquired data, increasing the reliability of the proposed measurement results.

[0076] The ultrasound image 1300 may be an ultrasound image acquired by the system 100 during an imaging procedure using 3D color Doppler techniques. As a result, various colors representing different velocities are seen in the upstream flow 1322 and jet 1324. By overlaying the model 1200 with the mitral valve 1230, the orifice 1242, and the virtual 3D color Doppler data on the image 1300, the accuracy of the model 1200 can be directly and quickly verified against the actual data. For example, the shape and orientation of the virtual upstream data 1222 may be visually compared to the actual upstream data 1322. Also, the colors in the virtual data 1222 and the actual data 1322 may be visually compared. In some embodiments, this comparison may be performed by a user. In other embodiments, the system 100 performs the comparison between the virtual color Doppler data 1222 and the actual color Doppler data 1322 using any of the image processing and / or machine learning techniques described above.

[0077] The model 1200 may include any suitable features. For example, the model 1200 may include iso-velocity surface meshes, velocity vector fields, streamlines, or any other features extrapolated from the model to show the validity of the proposed model to the actual mitral valve structure and color flow. In particular, the superposition of iso-velocity surfaces from the model and iso-velocity surfaces from the 3D color data provides a direct demonstration that the model constructed for quantification of mitral regurgitation matches the color data.

[0078] As shown in FIG. 13, an internal valve model showing the relationship between the detected valve morphology and the associated regurgitation may demonstrate the accuracy of the model. The system 100 may automatically extract features of the valve model (i.e., upstream suction flow, downstream jet, orifice, and / or mitral valve surface), which may result in a dynamic sequence of orifice detection and indication of regurgitation. By automatically extracting these features, the system 100 may also provide a more accurate and reliable quantification of regurgitation. The method may also be suitable for use at the patient side, as the model calculations are fast enough for real-time use.

[0079] 14 is an illustration of virtual three-dimensional Doppler volume data 1450 corresponding to a model of a mitral valve according to an aspect of the present disclosure. The illustrated virtual data 1450 may be two-dimensional or three-dimensional. The image 1400 shown in FIG. 14 may correspond to an alternative view of the virtual 3D color Doppler data generated by the system 100.

[0080] The virtual data 1450 shown in FIG. 14 includes several iso-velocity curves 1422 and virtual color data 1424. The virtual color data 1424 may be generated based on the blood flow model (e.g., a model of blood flow through the modeled orifice and mitral valve). This virtual color data 1424 may be generated to resemble the actually acquired color data for optimal comparison, as described in more detail with reference to FIG. 15. In some embodiments, as shown in the image 1400, the virtual data 1450 may be displayed from two different orientations. The axis lines 1410 and 1412 may be displayed to indicate the orientation. For example, the view of the virtual data 1450 displayed on the left side of the image 1400 may correspond to one cross-sectional view of the 3D color Doppler data 1450. The view on the right side may show the same virtual data 1450 from a different cross-sectional view. For example, the view shown on the right side of the image 1400 may be a view from a perpendicular angle to the view shown on the left side of the image 1400. The left and right images are side views of the virtual three-dimensional Doppler volume data 1450. The left and right images and / or the different planes or axes along the orientation of the left and right images may be automatically determined based on a valve model, an orifice model, and / or a flow model. The images and / or the different planes or axes may also be automatically determined based on an MPR. For example, the MPR may be based on the acquired 3D Doppler ultrasound data or a generated flow model.

[0081] The images may be based on the initial and / or modified shape of the opening. In this example, the opening may have a slit-like shape that is elongated in one direction, as shown by the view of data 1450 on the right side of image 1400, but narrow in the other perpendicular direction, as shown by the view of data 1450 on the left side. Thus, the image on the left may have an orientation along the short axis of the opening, and the image on the right may have an orientation along the long axis. This slit-shaped opening may result in a similarly shaped upstream flow and / or constant velocity curve, as shown. In some embodiments, axis 1410 and / or axis 1412 may correspond to a jet major axis, a valve normal axis, or a vertical axis. In the illustrated embodiment, axis 1410 is the jet axis and axis 1412 is the valve normal / vertical axis.

[0082] Fig. 15 is an illustration of acquired three-dimensional Doppler volume data 1550 in accordance with an aspect of the disclosure. The acquired Doppler volume data 1550 may be ultrasound data acquired by imaging the same opening that was modeled in generating the virtual data of Fig. 14. As a result, the acquired data 1550 may be used to verify the virtual data 1450.

[0083] FIG. 15 illustrates 3D color Doppler volume data 1550 acquired during an imaging procedure. The data 1550 includes an iso-velocity curve 1522 and color data 1524. In an example where the data 1550 is acquired data of the same aperture as that modeled to generate the virtual data 1450, the iso-velocity curve 1522 can be compared to the iso-velocity curve 1422. In this regard, the iso-velocity curve 1522 of FIG. 15 is generated based on the actual velocity determined based on the 3D color Doppler volume data. The iso-velocity curve 1422 of FIG. 14 is calculated based on a blood flow model. Based on the degree to which the curve 1522 and the curve 1422 match, the user or the system 100 can determine the accuracy of the virtual data 1450. Additionally, the acquired color data 1524 may be compared to the virtual color data 1424. Similarly, the system 100 or a user of the system can determine the accuracy of the virtual data 1450 based on the similarity of the color data 1524 and 1424.

[0084] For example, in one embodiment, the system 100 may compare individual pixels or other sections of the data 1450 to the data 1550. The velocity of the fluid may be known for each pixel or section of the data 1450 and 1550. The system 100 may determine the velocity difference between the same pixels in the virtual data 1450 and in the actual data 1550 and compare the difference to a threshold. As will be described in more detail below, if the velocity difference is greater than the threshold, the system 100 may conclude that the virtual data 1450 is inaccurate and needs to be discarded or modified. On the other hand, if the system 100 determines that the velocity difference for a given pixel or section is less than the threshold, it may be determined that the virtual data 1450 is accurate and correctly positioned and does not need to be discarded or adjusted.

[0085] Further shown in the image 1500 of FIG. 15 are axes 1510 and 1512. The axes 1510 and 1512 may be substantially similar to the axes 1410 and 1412 of FIG. 14 in that they may indicate the orientation of two views of the data 1550 shown. For example, the view of the virtual data 1550 displayed on the left side of the image 1500 may correspond to one cross-sectional view of the 3D color Doppler data 1550. The viewing angle of this view may be the same as the viewing angle of the view of the virtual data 1450 on the left side of the image 1400 of FIG. 14. With reference to FIG. 15, the view on the right side may show the same acquired data 1550 from a different cross-sectional view. For example, the view shown on the right side of the image 1500 may be a view from a perpendicular angle to the view shown on the left side of the image 1500. The view on the right side of the image 1500 may have the same viewing angle as the view on the right side of the image 1400 of FIG. 14. The left and right ultrasound images are side views of the 3D color Doppler volume data 1550. The left and right ultrasound images, and / or the different planes or axes along which the left and right ultrasound images are oriented, may be automatically determined using MPR. The ultrasound images may be based on the initial shape and / or the modified shape of the opening. For example, the ultrasound images may have orientations along the short and long axes of the opening, respectively. This advantageously provides the user with a more complete and accurate representation of openings having more complex shapes, non-circular, and / or irregular shapes (e.g., slit shapes).

[0086] It should also be noted that the image 1500 shown in Figure 15 further includes 3D Doppler data corresponding to downstream blood flow 1526. This downstream data 1526 need not be modeled in the virtual data 1450, but may be modeled. In some embodiments, the system 100 may determine the location of the mitral valve or mitral orifice relative to the acquired Doppler data 1550 shown in Figure 15. The system 100 may then compare only the upstream portion of the acquired Doppler data 1550 to the virtual data 1450.

[0087] Returning to FIG. 3, step 340 of method 300 includes adjusting the 3D model of the mitral valve and / or orifice to match the acquired 3D Doppler volume data. For example, the 3D model of the mitral valve and / or orifice is adjusted, thereby adjusting the blood flow model. Since the blood flow model is a model of the fluid dynamics through the structural model of the valve and orifice, the blood flow model may change depending on the change in the mitral valve model or orifice model. In step 340, the mitral valve model and / or orifice model may be adjusted until the resulting 3D blood flow model matches the acquired 3D Doppler data. In some embodiments, the match or correlation may be determined based on a threshold. For example, the degree of match or correlation may be quantified by a confidence index. The orifice model may be iteratively adjusted (and as a result, the 3D blood flow model may be adjusted) until it meets the confidence index (e.g., until it meets or exceeds a threshold). For example, the indicators may be based on, for example, the degree of numerical overlap between the velocities provided by the flow model and the velocities provided by the 3D Doppler ultrasound data, and / or the degree of spatial overlap of different velocity regions provided by the flow model and the 3D Doppler ultrasound data. The 3D characteristics of the modeled blood flow and the actual acquired blood flow may be used to validate the model of blood flow through the mitral valve opening in each frame of the regurgitant sequence. Aspects of step 340 are described with reference to FIGS. 16-18. FIG. 16 is a schematic diagram of a comparison of a model 1650 of blood flow data and acquired blood flow data 1610 prior to adjustment of the model 1650, in accordance with aspects of the present disclosure. The model 1650 may be shown in two or three dimensions. The acquired blood flow data 1610 shown in FIG. 16 includes multiple regions of varying velocities indicated by different colors, including regions 1612, 1614, and 1616. A centerline 1620 and a border 1622 are also identified. The model 1650 includes a seed point 1640 , a number of aperture location points 1642 , and three constant velocity curves, including curve 1652 , curve 1654 , and curve 1656 .

[0088] The illustrated model 1650 may be an additional view of or may be based on models of surface area, velocity, and flow of iso-velocity curves, and models of modeled orifice and mitral blood flow. For example, the model 1650 may be based on any of the data or calculations described with reference to any of Figures 10-15. After the model 1650 is generated, it may be adjusted and / or scaled to correspond to the acquired 3D color Doppler data 1610.

[0089] The system 100 may identify a centerline 1620 of the acquired Doppler data 1610. In some embodiments, the downstream jet portion 1611 of the acquired data 1610 may be used to determine the centerline 1620. For example, the acquired data 1610 may include regions 1612, 1614, and 1616. These regions may correspond to regions of the same or similar velocity. For example, blood may be moving at the same velocity at all points in three-dimensional space along a boundary 1622 of the region 1612. These boundary lines 1622 may be used to determine the centerline 1620. In some embodiments, the system 100 may determine all positions that are equidistant from each boundary line 1622 along the region 1612 of the downstream data 1611. These equidistant positions may define the centerline 1620.

[0090] The centerline 1620 may be the axis about which the model 1650 is oriented. The centerline 1620 may also be called the jet axis or valve normal.

[0091] Based on the location of the centerline 1620, the system 100 can determine the location of a seed point 1640. The seed point 1640 can be an initial estimated location of the center of the aperture. The seed point 1640 can determine the initial position / orientation of a model 1650 overlaid on the acquired data 1610. The seed point 1640 can be placed at a point along the centerline 1620. The system 100 can use any suitable method to determine the location of the seed point 1640 along the centerline 1620. In one embodiment, the system 100 can use any of the image processing techniques described above to determine the location of the aperture and place the seed point at that location along the centerline 1620.

[0092] Based on the location of the seed point 1640, the aperture point 1642 and associated constant velocity curves 1652, 1654, and 1656 may be positioned / oriented within the image 1600. In an embodiment, the aperture point 1642 may be or correspond to a source point used to calculate the constant velocity curves 1652, 1654, and 1656 using the principles described with reference to FIG. 10. The aperture point 1642 may be initially located at the same position as the seed point 1640 along the centerline 1620. In some embodiments, the size or scale of the model 1650 may be determined based on the boundary line 1622 of the jet. For example, the aperture point 1642 may be positioned to extend from one boundary line 1622 to the other boundary line as shown in FIG. 16. The associated constant velocity curves may be scaled to match the scale of the resulting aperture point 1642.

[0093] The orientation of the model 1650 may be determined in any suitable manner. For example, the model 1650 may be oriented such that a line defined by the opening points 1642 is perpendicular to the centerline 1620 and / or the boundary line 1622. In other embodiments, the model 1650 may be oriented such that the opening points 1642 are aligned substantially parallel to the surface of the mitral valve. Other factors may also affect the initial placement / orientation of the model 1650, such as the size and orientation of the acquired color Doppler data, the downstream jet, or other characteristics of the image 1600.

[0094] After the model 1650 has been initially positioned in the image 1600 according to the principles described above, the system 100 can analyze the image 1600 to determine whether the model has been accurately and properly positioned. The system 100 can use various image processing and machine learning techniques, as described above, to identify relevant features in the acquired data 1610 and in the model 1650 for comparison.

[0095] In one embodiment, the system 100 can determine the velocity of the fluid measured by the 3D color Doppler data 1610. As shown in FIG. 16, region 1616 may behave like a constant velocity curve of uniform velocity in the region upstream of the mitral valve. Such a constant velocity curve may correspond to the outer edge of the illustrated region 1616. Similarly, region 1614 may correspond to a constant velocity curve of uniform velocity in the upstream region. Region 1614 may represent a region of higher velocity than region 1616. The outer edge of region 1614 may correspond to a constant velocity curve. Similarly, region 1612 may correspond to a constant velocity curve of uniform velocity in the upstream region. Region 1612 may represent a region of higher velocity than both region 1614 and region 1616. The outer edge of region 1612 may correspond to a constant velocity curve.

[0096] In some embodiments, the system 100 can generate iso-velocity curves 1652, 1654, and 1656 of the blood flow model 1650 based on the measured velocities of the regions 1612, 1614, and 1616. For example, the curve 1652 can be at the same velocity as the region 1612, the curve 1654 can be at the same velocity as the region 1614, and the curve 1656 can be at the same velocity as the region 1616. Based on this relationship, the system 100 can determine that the model 1650 needs to be moved so that the curves 1652, 1654, and 1656 coincide with the outer edges of the regions 1612, 1614, and 1616, respectively. The blood flow model 1650 can be adjusted by adjusting the models of the corresponding openings. For example, if the opening models in the mitral valve model are adjusted or repositioned / reoriented, the blood flow model 1650 can be adjusted or repositioned / reoriented accordingly. Such adjustment, repositioning / reorienting, or alignment is illustrated in FIG. 17, described below.

[0097] The system 100 may adjust the position / orientation of the model 1650 by changing characteristics such as the position, rotation, or shape of the orifice model in any suitable manner. For example, the system 100 may incrementally change the position of the orifice model, thereby changing the position of the blood flow model 1650. For example, the position of the orifice may be moved along a direction or axis perpendicular to the valve. The position of the orifice model may be changed in depth, or the position may be changed upstream or downstream of the mitral valve, or the position may be adjusted in any other direction, for example, laterally along the plane of the mitral valve. The system 100 may also incrementally change the rotation / orientation of the model 1650. In some embodiments, the system 100 may change the definition or shape of the modeled orifice by adjusting a velocity threshold, as described in more detail with reference to FIG. 18.

[0098] FIG. 17 is a schematic diagram of a comparison of a model 1650 of blood flow data with acquired blood flow data 1610 after adjustment of the model 1650, according to aspects of the disclosure. As described with reference to FIG. 17, the constant velocity curves of the model 1650 may be aligned with the outer edges of the regions 1612, 1614, and 1616 of the acquired data 1610. When the aperture point 1642 is adjusted, the blood flow model including the illustrated constant velocity curves is also adjusted as shown. In some embodiments, the aperture point 1642 may still be constrained to be located along the centerline 1620 and extend from the boundary 1622 of the jet region 1612, as shown in FIG. 17 and described with reference to FIG. 16. In other embodiments, this constraint may not be imposed. As described with reference to FIGS. 16 and 17, the processor circuit 210 may adjust or modify the model of the aperture such that the blood flow model is also modified to match the acquired Doppler data.

[0099] After the model 1650 has been repositioned / reoriented within the image 1600, the system 100 can again verify that the model 1650 is correctly positioned / oriented and accurately reflects the actual acquired data 1610. As noted above, this can be done in a variety of ways. In some embodiments, the system 100 may perform a pixel-by-pixel or section-by-section comparison of the modeled data 1650 and the acquired data 1610. If each compared pixel or section meets a predefined threshold of velocity, flow, or position difference, the system 100 can determine that the model 1650 is correctly positioned and accurately reflects the flow through the imaged aperture.

[0100] 18 is a schematic diagram of a model 1810 of the mitral valve orifice after velocity threshold adjustment, according to aspects of the present disclosure. The model 1810 may be shown in two or three dimensions. Referring to FIG. 16, in some applications, adjustments to the model 1650 may not only be with respect to position / orientation, but may also require changing the shape of the model orifice to accurately reflect the flow.

[0101] One way to redefine the shape of the orifice is to change the velocity threshold for each point of a model of the mitral valve or mitral orifice. As described above with reference to FIG. 7, the system 100 can define the orifice by dividing the plane of the mitral valve into sections. The velocity indicated by the 3D color Doppler data of each section can determine whether the system 100 classifies the section as corresponding to the mitral valve or orifice. For example, if a particular section exhibits a velocity higher than a threshold, the system 100 can determine that blood is flowing through the section and classify the section as a section of an orifice. Alternatively, if a particular section exhibits no velocity or exhibits a velocity below a predetermined threshold, based on the 3D color Doppler data, the system 100 can classify the section as corresponding to a section of the mitral valve through which blood does not flow.

[0102] Referring again to FIG. 18, a model 1810 of the mitral valve and orifice is shown. The mitral valve model is constructed with a number of sections or points. These sections or points are indicated by a number of blocks 1825 in the illustrated model 1810. The orifice in the model 1810 is also constructed with a number of sections or points, indicated by block 1820. As described above, if the system 100 determines that the actual orifice is smaller than the modeled orifice based on a comparison of the modeled and measured flow data, the system 100 may incrementally increase the threshold velocity. As the threshold velocity increases, fewer blocks of the model 1810 will exhibit above the threshold and will not be included in the orifice model. Those blocks that were initially included in the orifice model but have been converted from the orifice block 1820 to the mitral valve block 1825 are indicated by block 1830. Thus, velocity thresholding may be used to change the shape of the orifice (e.g., the definition of the orifice in the valve model).

[0103] As the threshold velocity is increased in increments, the system 100 may again compare the flow of the resulting model 1650 to the actual flow data 1610 to determine whether the threshold velocity produces an accurate model. As shown in FIG. 18, a constant velocity curve 1832 may be generated that corresponds to the newly updated model based on the higher velocity threshold. The constant velocity curve 1832 may represent points in three-dimensional space surrounding the newly modeled opening shown where fluid moving toward the opening moves at the same velocity. The constant velocity curve 1832 may be one of several components of the flow model that corresponds to the newly modeled opening.

[0104] In some embodiments, the processor circuitry can output a graphical representation of the modified orifice model 1820 having a different shape, a different position, and / or a different orientation. For example, a representation of the orifice model 1820 may be provided within the valve model 1810 (e.g., as a graphical overlay). In some embodiments, a graphical representation of the modified orifice model 1820 and / or the valve model 1810 (e.g., as a graphical overlay) may be displayed on an ultrasound image generated using the Doppler and / or B-model ultrasound data. In some embodiments, the processor circuitry outputs the modified orifice model 1820 that results in a regurgitation model that is consistent with the 3D Doppler ultrasound data. The displayed modified orifice model may be referred to as a regurgitation orifice in some embodiments. The final orifice model, or an intermediate orifice model between the initial and final versions, may be displayed. In some embodiments, the processor circuitry can output one or more iterations of the modified orifice model 1820.

[0105] Referring again to FIG. 3, in step 345, the method 300 includes calculating a volumetric flow rate and an orifice area based on the adjusted 3D model. The adjusted 3D model may include a blood flow model, a model of the orifice, and / or a model of the mitral valve. Because the blood flow model has been adjusted in step 340 to match the acquired 3D Doppler data, measurements based on the blood flow model and / or the orifice model are accurate. In step 350, the processor circuit 210 (FIG. 2) may calculate a blood flow rate measurement through the orifice for any of the acquired ultrasound images. The processor circuit may also calculate an orifice area measurement for any of the acquired ultrasound images. As described with reference to FIG. 10, the total volumetric flow rate through the orifice may be calculated as a convolution of the flows through multiple point sources that make up the orifice. This flow may be calculated in units of volume per unit time, such as milliliters per second, or other suitable units. It is noted that this flow calculation corresponds specifically to the image frame being analyzed. For example, referring to step 315, if n=0, then this flow calculation corresponds to the first ultrasound image frame 514 (FIG. 5) in systole.

[0106] In addition to the volumetric flow metric, the system 100 can also calculate the area of ​​the openings in the selected ultrasound image frame. This metric may be directly related to the number of opening blocks 1820 (FIG. 18) after any necessary adjustments have been made to the model, or may be done in another manner. For example, the system 100 can use any of the image processing or machine learning techniques described above to identify the openings, determine the radius, diameter, or other measurement of the openings, and determine the area of ​​the openings.

[0107] After the volumetric flow rate and opening area are calculated for the identified ultrasound images, these indices may be stored in a memory, such as memory 138 (FIG. 1) or memory 264 (FIG. 2). These indices may be associated with the analyzed ultrasound image and the patient's file. In step 350, method 300 includes determining whether there are additional ultrasound image frames that have not yet been analyzed within frame set 510 corresponding to the systole identified by indicator 530 of Figure 5. For example, after a first ultrasound image frame 514, n=0 (as in step 315) has been analyzed by system 100 according to steps 320-345, in step 350 system 100 may determine that there are ultrasound image frames from the systole that have not yet been analyzed, and system 100 proceeds to step 355.

[0108] In step 355, method 300 includes incrementing integer n by 1. For example, after the first image frame 514 (FIG. 5) is analyzed in steps 320-345, in step 355, integer n may advance to n=1. This increment of integer n may signal system 100 to select the next ultrasound image frame acquired immediately after frame 514 and analyze this next frame in accordance with steps 320-345 of method 300. After this is completed, in step 355, integer n may again be incremented by 1 (i.e., n=2) and the next acquired image may be analyzed. This process may continue until the last ultrasound image of the systole is analyzed in accordance with steps 320-345. By completing steps 320-345 for each ultrasound image corresponding to the systole, the volumetric flow rate and orifice area may be accurately determined throughout the systole, despite the dynamic mitral valve surface continuing to move. This may account for temporal variations in the hemodynamics of blood flow during mitral regurgitation, which may result in more accurate measurements. After the last ultrasound image of the systole has been analyzed, the system 100 may proceed from step 350 to step 360.

[0109] In step 360, the method 300 includes outputting a screen display. Step 360 will be described with reference to FIGS. 19-22. FIG. 19 is a schematic diagram of a graphical user interface 1900 displaying an image 1910 and associated metrics, according to an aspect of the present disclosure. After the system 100 acquires 3D color Doppler data of the mitral valve and generates, compares, and adjusts the virtual model of the data of each ultrasound image frame during systole, the system 100 can display the results to the user. It should be noted that the system 100 can additionally display various displays (including any of the depictions of the drawings illustrated and described herein, or other depictions) to the user during any of the enumerated steps of the method 300. The graphical user interface 1900 displaying the obtained data to the user can include any suitable features or elements, including or in addition to those illustrated and described in FIG. 19. The graphical user interface 1900 may be displayed to the user during an ultrasound imaging procedure in a point of care environment, or at some point thereafter. From a high level, the display may include a representation of a flow model upstream of the orifice superimposed on the original color Doppler data, with quantification of flow and orifice area during systole. The screen display displayed by the processor circuit 210 (FIG. 2) shown in FIG. 19 may include a representation of ultrasound data (e.g., ultrasound data received in step 305 of method 300 (FIG. 3)), a model of the mitral valve (e.g., a model described with reference to FIG. 6), a model of the orifice (e.g., a model described with reference to FIG. 7 and / or FIG. 10, FIG. 12, FIG. 13, FIG. 17, or FIG. 17), a model of blood flow through the orifice (e.g., a model described with reference to FIG. 10), a volumetric blood flow (e.g., a volume calculated in step 345 of method 300 (FIG. 3)), an orifice area (e.g., an area calculated in step 345 of method 300 (FIG. 3)), or an indication of the total amount of blood passing through the mitral valve orifice throughout systole, as described in more detail with reference to FIG. 22.

[0110] However, in one example, FIG. 19 may include image 1910, indicator 1920, and indicator 1930. Image 1910 may be any suitable image associated with an imaging procedure of the mitral valve, or other related depiction. In one embodiment, image 1910 may be a color Doppler ultrasound image showing the mitral valve permitting regurgitation during systole, such as image 400 of FIG. 4. Image 1910 may be a color Doppler ultrasound image from the diastole of the cardiac cycle. In some embodiments, image 1910 may be a B-mode ultrasound image. In some embodiments, image 1910 may show a generated model of the mitral valve, such as the model shown in image 600 of FIG. 6, model 1010 of FIG. 10, image 1100 of FIG. 11, image 1200 of FIG. 12, image 1400 of FIG. 14, or model 1810 of FIG. 18. In some embodiments, image 1900 may show a comparison of virtual flow data or a corresponding model with acquired color Doppler data, such as the depictions of FIG. 13, FIG. 16, or FIG. 17. Image 1900 may be similar to image 1500 of FIG. 15. Also, in some embodiments, image 1900 may be similar to image 2000 of FIG. 20, image 2100 of FIG. 21, or graph 2200 of FIG. 22, which will be described later. Image 1900 may include any one of these example images, or may include some or all together in a single image. Image 1900 may include any suitable annotations within the image, such as drawings, indicators, symbols, or alphanumeric text. Such annotations may be created in response to user input or may be created automatically. These annotations may be overlaid on top of image 1900 or may be located adjacent to image 1900.

[0111] The image 1910 may be static or dynamic. For example, the image 1910 may be any of the images listed above, or may be a dynamic image showing a sequence of several ultrasound image frames. The image 1910 may be a dynamic model showing the mitral valve, orifice, blood flow, and any visual indicators of flow (e.g., iso-velocity curves, vectors, or other indicators over time or throughout systole). In some embodiments, the image 1910 may be a real-time dynamic image showing the patient's anatomy. This real-time dynamic image may also be overlaid on the ultrasound image frames to display various aspects of the blood flow model or the valve or orifice model. In some embodiments, such a dynamic image frame sequence may be viewed shortly after the ultrasound images are acquired or after the imaging procedure.

[0112] The graphical user interface 1900 may further include various indices, including indices 1920 and 1930. The indices 1920 and 1930 may correspond to any suitable measurement or calculation. As an example, the indices 1920 may correspond to an indication of the volumetric flow rate through the opening of the mitral valve. As noted above, this may have units of volume per unit time, such as milliliters per second, or other suitable unit format. The flow rate may convey to the user the calculated volumetric flow rate through the opening of the particular image frame shown in the image 1910. The volumetric flow rate may further indicate the flow at other times during systole. In some embodiments, the indices 1920 may correspond to the total amount of blood that has passed through the opening of the mitral valve throughout systole.

[0113] In some embodiments, the indicator 1930 may correspond to an aperture area at a particular time. For example, the indicator 1930 may convey to a user the opening area of ​​an aperture in a particular ultrasound image displayed as part of the image 1910. In other embodiments, the indicator 1930 may be or include other measurements related to the aperture, such as the radius or diameter of the aperture, the length of time or number of ultrasound image frames that the aperture remains open, the number of apertures identified in a particular ultrasound image frame, or other suitable indicator.

[0114] In some embodiments, the graphical user interface 1900 may include a display of the regurgitant flow distribution overlaid on a 2D or 3D display of the acquired ultrasound data using an iso-mesh or iso-lines. The display may include a 2D or 3D vector flow field displayed as streamlines or vectors. The display may also include a multiplanar reconstruction (MPR). The MPR may be defined to provide an optimal cross-section through the 3D ultrasound gray value and flow data. These orientations may be defined using the principal direction of the orifice, or the principal axis of the orifice shape, such as the jet principal axis or the valve normal. Any of these above displays or images may be displayed as cross-sections or rendered in three dimensions. In some embodiments, the orifice contours may be drawn on the estimated valve surface.

[0115] 20 is a schematic illustration of modeled and adjusted blood flow data overlaid on a cross-section of a three-dimensional color Doppler ultrasound image 2000 according to an aspect of the present disclosure. Image 2000 may be included in a graphical user interface, such as graphical user interface 1900 just described. For example, image 2000 may be image 1910 in interface 1900. Image 2000 may be displayed to a user of system 100 in other ways. Image 2000 includes acquired 3D color Doppler data 2050 and virtual flow data including a number of iso-velocity curves 2042 and flow vectors 2040. This virtual blood flow data may include two-dimensional data and / or three-dimensional data.

[0116] As indicated by line 790, image 2000 may be a cross-section of the same three-dimensional data used to generate image 700 of Figure 7. Specifically, referring again to Figure 7, line 790 extends through the center point of opening 742. Because image 700 is an image showing a plane substantially parallel to the mitral valve so that the hole of opening 742 is visible, the cross-section indicated by line 790 may show a vertical view of the mitral valve as seen from the side separating the left ventricle 2020 and the left atrium 2010.

[0117] The color Doppler data 2050 shown in FIG. 20 illustrates the movement of blood from the ventricle 2020 to the atrium 2010 as observed by the ultrasound system 100. The modeled virtual blood flow data, including curve 2042 and vector 2040, are shown aligned with the color Doppler data 2050. At this point, the calculated curve 2042 and vector 2040 (from the flow model) are overlaid on the ultrasound image 2000 with the acquired color Doppler data 2050. For example, the outermost iso-velocity curve 2042 closely matches the outer edge of the upstream color Doppler data 2050 in the ventricle 2020. Similarly, additional iso-velocity curves can be seen to match the edge of a color change (indicative of an increase in velocity) in the color Doppler data 2050 closer to the opening of the mitral valve.

[0118] In addition to the curves 2042, the virtual blood flow model data may include vectors 2040. The vectors 2040 shown in FIG. 20 may be positioned perpendicular to the constant velocity curves. The direction of the vectors 2040 may indicate the direction of blood movement. Also, in some embodiments, the relative velocity of blood at various locations within the ventricle may be indicated by the length of the vectors 2040.

[0119] 20 can advantageously indicate to a user the location and extent of mitral regurgitation within a patient's heart, and coupled with the increased accuracy of the flow and area measurements provided, the present disclosure provides a greatly enhanced diagnostic tool for physicians to accurately ascertain the extent of cardiac disease such as mitral regurgitation.

[0120] 20 also shows an axis 2090 passing through the orifice. In general, the axis 2090 may identify the jet major axis, the valve normal axis, or the vertical axis of the blood flow. In some embodiments, the axis 2090 may identify the center point of the orifice, or any other feature of the mitral valve, the orifice, or the blood flow. In the illustrated embodiment, the axis 2090 is the jet axis.

[0121] FIG. 21 is a schematic illustration of modeled and adjusted blood flow data superimposed on a cross section of a three-dimensional color Doppler ultrasound image according to aspects of the present disclosure. Similar to image 2000 of FIG. 20, image 2100 may be included in a graphical user interface such as graphical user interface 1900 described above. For example, image 2100 may be image 1910 in interface 1900. Image 2100 may be displayed to a user of system 100 in other ways. Image 2100 includes acquired 3D color Doppler data 2050 shown in FIG. 20 and virtual flow data including iso-velocity curves 2042 and flow vectors 2040. However, as indicated by line 792, image 2100 may be a different angle cross section of the same three-dimensional data. For example, similar to image 2000, image 2100 may be generated from the same data used to generate image 700 of FIG. 7. Referring again to FIG. 7, line 792 extends through the center point of opening 742. Since image 700 is an image showing a plane substantially parallel to the mitral valve so that the hole of opening 742 is visible, the cross section shown by line 792 may show a vertical view of the mitral valve as seen from the side separating the left ventricle 2020 and the left atrium 2010. As shown in Figure 7, the cross section shown by line 790 in Figure 20 may be substantially perpendicular to the cross section shown by line 792 in Figure 21.

[0122] Similar to Fig. 20, the color Doppler data 2050 shown in Fig. 21 shows the movement of blood from the ventricle 2020 to the atrium 2010. The modeled virtual blood flow data, including curves 2042 and vectors 2040, are shown aligned with the color Doppler data 2050, with the outermost iso-velocity curve 2042 coinciding closely with the outer edge of the upstream color Doppler data 2050 in the ventricle 2020. In this example, two openings are shown from the angle indicated by the cross section at 792, so two sets of iso-velocity curves may be displayed.

[0123] 21 may also be positioned perpendicular to the constant velocity curve. The direction of the vector 2040 may indicate the direction of blood movement. Also, in some embodiments, the length of the vector 2040 may indicate the relative velocity of blood at various locations within the ventricle.

[0124] 22 is a schematic illustration of a graph 2200 displaying measurements of volumetric regurgitant volume 2210 and orifice area 2220 throughout the systolic phase of the cardiac cycle, in accordance with aspects of the present disclosure. The graph 2200 can provide a user of the system 100 with a graphical display of both the volumetric regurgitant volume throughout the systolic phase, and the orifice area of ​​the mitral valve orifice.

[0125] Graph 2200 includes a horizontal axis 2292 and two vertical axes, namely, axis 2290 and axis 2294. Horizontal axis 2292 may correspond to a measurement of time. For example, horizontal axis 2292 may indicate time in seconds. Any unit of time may be used in the illustration of horizontal axis 2292. Alternatively, horizontal axis 2292 may refer to image frames. For example, the leftmost portion of horizontal axis 2292 may correspond to an image frame acquired at the beginning of systole (i.e., frame 514 in FIG. 5). Thus, the rightmost portion of horizontal axis 2292 may correspond to an image frame acquired at the end of systole.

[0126] The vertical axis 2290 may correspond to a volumetric flow rate. As noted above, this volumetric flow rate may be expressed in unit volume per unit time, such as ml / s as shown, but may be in any suitable units.

[0127] The vertical axis 2294 may correspond to the aperture area. As shown, the unit of measure for the aperture area may be square millimeters. However, any other suitable unit of area may be used to measure the aperture area.

[0128] Graph 2200 further illustrates two curves, curve 2210 and curve 2220, corresponding to volumetric flow rate over time and orifice area over time, respectively. These curves may be generated based on the measured volumetric flow rate and orifice area, respectively, of each ultrasound image acquired and analyzed in steps 320-345 of method 300. These values ​​may be retrieved from memory to generate curve 2210 and curve 2220.

[0129] Several points 2212 are shown positioned along the curve 2210. These points may correspond to ultrasound image frames. For example, the point 2212 identified in the graph 2200 may correspond to the second ultrasound image frame of the systole acquired and analyzed. As an example, the volumetric flow rate measured at this particular frame is about 120 ml / s. In some embodiments, the points 2212 may not be positioned along the curve 2210 for every ultrasound image frame from the systole acquired and analyzed. For example, the points 2212 may be positioned along the curve 2210 every second, third, fourth, or more frames. In some embodiments, the system 100 or a user of the system 100 may add additional points 2212 along the curve to identify various regions of interest along the curve or for other reasons. Also, the user or the system 100 may remove one, some, or all of the points 2212 from the graph 2200.

[0130] Similarly, there are shown a number of points 2222 positioned along the curve 2220. Like the points 2212, these points 2222 may or may not correspond to individual ultrasound image frames. The points 2222 may be spaced apart similar to the points 2212, and the user or the system 100 may add or remove points 2222.

[0131] In some embodiments, a user of the system 100 may wish to know the total volume that passed through the mitral valve opening during systole. In some embodiments, this metric may be determined by integrating all of the known flow data that creates a volumetric flow curve 2210 (e.g., the area under the curve). The total amount of regurgitant volume throughout systole may help a physician determine the appropriate treatment for a leaking mitral valve.

[0132] In some embodiments, the processor circuitry may calculate a confidence index that evaluates the correlation / match between the flow model and the 3D Doppler ultrasound data. For example, the index may be based on, for example, the degree of numerical overlap between the velocities provided by the flow model and the 3D Doppler ultrasound data, and / or the degree of spatial overlap of different velocity regions provided by the flow model and the 3D Doppler ultrasound data. The confidence index may be output as a curve. For example, the confidence index may be plotted along the y-axis over time along the x-axis. Each point may correspond to a particular shape of the aperture model. The value of the confidence index increases as the aperture model improves over time. In some embodiments, the confidence index may be plotted along the y-axis over multiple image frames along the x-axis. The curve corresponds to one iteration of the aperture model (e.g., the initial aperture model, the final aperture model, or an intermediate aperture model between the initial and final versions). The curve provides a confidence index for each image frame, which may or may not change depending on the ultrasound data of that image frame and / or the calculated flow model of that frame.

[0133] FIG. 23A shows a schematic diagram of a blood flow model 2300 according to aspects of the present disclosure. FIG. 23A includes a depiction of an orifice model 2342, three-dimensional streamlines 2340, and velocity vectors 2350 and 2352. As shown in FIG. 23A, the processor circuit 210 can generate a four-dimensional mitral regurgitation model. This 4D mitral regurgitation model can include, among other things, various quantifications of blood flow through the orifice 2342 throughout systole. The model 2342 can be a 3D surface rendering model of the orifice.

[0134] As shown in FIG. 23A, the streamlines 2340 may indicate the direction of flow of blood moving through the opening 2342. The streamlines 2340 may be 3D and may be calculated and / or derived from the shape of the opening 2342. As described above with reference to FIG. 3, a blood flow model such as the illustrated model 2300 may be generated for each ultrasound image received by the system 100. In this manner, the blood flow model may change over time. Thus, the model 2300 may indicate the direction and velocity of blood throughout the three-dimensional space immediately surrounding the mitral valve throughout the time dimension (fourth dimension). In some embodiments, the streamlines 2340 may further visually indicate the velocity of blood flow at various locations around the mitral valve orifice 2342 by varying their appearance. For example, the streamlines 2340 may include arrows 2341 positioned along the streamlines 2340. The relative positions of these arrows 2341 may indicate relative velocities. For example, a high density of arrows 2341 along a particular streamline 2340, i.e., closer spacing between the arrows 2341, may indicate a higher velocity than a streamline in which the arrows 2341 are less densely spaced, i.e., more widely spaced between the arrows 2341.

[0135] Model 2300 may further include velocity vectors 2360 and / or 2362 as shown. Velocity vectors 2360 and 2362 may also indicate the speed and direction of blood flow defined by blood flow model 2300 at various locations in space. Additional velocity vectors may be located throughout space, either automatically by system 100 or as prompted by user input. One velocity vector, e.g., velocity vector 2360, may correspond to a different location and / or time than another velocity vector, e.g., velocity vector 2362.

[0136] At each frame t, the backflow is calculated from the velocities along the computed 3D streamlines 2340.

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[0137] 23B shows a schematic diagram of a blood flow model 2350 according to aspects of the present disclosure. The model 2350 may be substantially similar to the model 2300 described with reference to FIG. 23A. For example, the model 2350 may be a different view of the model 2300. The model 2350 may include the same opening 2342, streamlines 2340, and velocity vectors 2360 and 2362. Thus, the model 2350 may also include four-dimensional data including velocity magnitude and direction data of the blood flow near the opening 2342. In other embodiments, the model 2350 represents different openings 2342, streamlines 2340, and velocity vectors 2360 and 2362.

[0138] 24 is a schematic diagram comparing a blood flow model 2460 generated using a computational fluid dynamics technique to a blood flow model 2450 generated using a hole geometry flow model according to aspects of the present disclosure. The illustrated image 2400 reflects a comparison of a blood flow model 2450 created using the techniques and methods described in this disclosure. For example, model 2450 includes multiple velocity vectors that indicate blood flow through two openings, opening 2442 and opening 2444.

[0139] For comparison, model 2460 is also shown. Model 2460 may have been generated using computational fluid dynamics (CFD) techniques. CFD techniques are believed to be accurate, but are computationally intensive for practical use in real-time imaging procedures. CFD is computationally intensive because it requires numerically solving the physical equations governing the behavior of the fluid. To ensure stability and accuracy of the calculations, the domain must be discretized in space and time using small spatial and time steps, which advantageously is not required according to the present disclosure. However, as shown in image 2400, the presently disclosed method, i.e., the hole-shaped flow model, provides results that are at least as accurate as CFD, while providing a significantly faster and more efficient algorithm. Unlike CFD, aspects of the present disclosure can advantageously be performed in real-time or near real-time, or live during an ultrasound imaging procedure. This can provide additional clinical information to the physician while the procedure itself is taking place. As shown by the velocity vectors of model 2460 of the CFD technique compared to the velocities of model 2450 of the hole-shaped model, the blood flow models generated with both techniques are very accurate. The improved speed and efficiency of the hole-shaped flow model allows for easier visualization and quantification of mitral regurgitation during patient-side imaging procedures, therapeutic procedures, or a variety of other settings, while maintaining or in some cases improving accuracy compared to previous algorithms.

[0140] The disclosure has been described using examples such as mitral regurgitation, mitral valve, blood flow, left ventricle, and left atrium. However, other examples are contemplated. Aspects of the disclosure may be applied to any flow of any fluid between any volumes / chambers / lumens (whether natural or artificial) with a valve intervening therebetween. For example, the disclosure may be used for aortic regurgitation associated with the tricuspid valve. Additionally, variations of the algorithm may be used to calculate inflow from the mitral valve, i.e., blood flow from the left atrium to the left ventricle.

[0141] Those skilled in the art will recognize that the above-mentioned devices, systems, and methods may be modified in various ways. Therefore, those skilled in the art will understand that the embodiments covered by the present disclosure are not limited to the specific embodiment examples above. Although illustrative embodiments have been shown and described, the above disclosure contemplates various modifications, changes, and substitutions. It is understood that such modifications may be made above without departing from the scope of the present disclosure. Therefore, it is appropriate that the appended claims be broadly construed in accordance with the present disclosure.

Claims

1. An ultrasonic system comprising an array of acoustic elements for acquiring ultrasonic data including three-dimensional Doppler data and B-mode data, and a processor circuit communicating with the array of acoustic elements and a display, wherein the processor circuit: receives the ultrasonic data acquired by the array of acoustic elements, the ultrasonic data representing mitral valve regurgitation associated with an opening of the mitral valve; generates a three-dimensional model of the mitral valve based on the B-mode data; generates a model of the opening based on the three-dimensional model of the mitral valve and the three-dimensional Doppler data, the model of the opening having a set of points located on the three-dimensional model of the mitral valve; outputs a first screen display to the display, the first screen display including the three-dimensional model of the mitral valve and the model of the opening within the three-dimensional model of the mitral valve; generates a blood flow model of the mitral valve regurgitation based on the model of the opening by associating each point of the set of points with a flow model of a source point and calculating the convolution of the flow models associated with each of the set of points; compares the blood flow model with the three-dimensional Doppler data; changes the model of the opening such that the blood flow model is changed to match the three-dimensional Doppler data, the model of the opening being changed to have at least one of a different shape, a different position, or a different orientation; outputs a second screen display to the display, the second screen display including an ultrasonic image based on the ultrasonic data and the model of the opening within the ultrasonic image, the model of the opening within the second screen display including at least one of the different shape, the different position, or the different orientation. An ultrasonic system configured to perform the above.

2. The ultrasonic system according to claim 1, wherein the three-dimensional model of the mitral valve includes an anatomical model of the mitral valve, and generating the model of the opening includes identifying an opening within the anatomical model of the mitral valve based on the three-dimensional Doppler data. ​ ​ ​ ​ ​ ​

3. The ultrasonic system according to claim 2, wherein the processor circuit identifies the opening based on a velocity within the three-dimensional Doppler data that exceeds a threshold velocity.

4. The ultrasonic system according to claim 3, wherein the processor circuit changes the shape of the opening by changing the threshold velocity.

5. The ultrasonic system according to any one of claims 1 to 4, wherein the processor circuit changes the position of the opening by moving the opening along a vertical direction in the three-dimensional model of the mitral valve.

6. The ultrasonic system according to claim 1, wherein the processor circuit outputs a 3D isovelocity surface based on the blood flow model of the mitral valve regurgitation.

7. The second screen display includes a first ultrasonic image based on the ultrasonic data and a second ultrasonic image based on the ultrasonic data, the first ultrasonic image has an orientation along a first axis, the second ultrasonic image has an orientation along a second axis different from the first axis, the ultrasonic system according to claim 1.

8. The ultrasonic system according to claim 7, wherein the first ultrasonic image and the second ultrasonic image are (i) based on multi-plane reconstruction or (ii) include side views.

9. The ultrasonic system according to claim 7, wherein the first axis and the second axis correspond to at least one of the shape of the opening or the modified shape.

10. The processor circuit determines at least one of a flow rate, an opening area, or a reliability metric, The ultrasonic system according to claim 1, wherein the processor circuit outputs a graphical representation based on at least one of the flow rate, the opening area, or the reliability metric to the display.

11. A computer-implemented method for visualizing and quantifying mitral valve regurgitation, the method comprising: receiving ultrasonic data acquired by an array of acoustic elements of an external ultrasonic imaging device, the ultrasonic data representing mitral valve regurgitation associated with an opening of a mitral valve, the ultrasonic data having three-dimensional Doppler data and B-mode data; generating a three-dimensional model of the mitral valve based on the B-mode data; Generating a model of the opening based on the three-dimensional model of the mitral valve and the three-dimensional Doppler data, wherein the model of the opening has a set of points located on the three-dimensional model of the mitral valve; Outputting a first screen display to a display, wherein the first screen display; includes the three-dimensional model of the mitral valve; and the model of the opening within the three-dimensional model of the mitral valve; Generating a blood flow model of mitral valve regurgitation based on the model of the opening by associating each point of the set of points with a flow model of a source point and calculating the blood flow model of mitral valve regurgitation as a convolution of the flow models associated with each of the set of points; Comparing the blood flow model with the three-dimensional Doppler data; Changing the model of the opening such that the blood flow model is changed to match the three-dimensional Doppler data, wherein the model of the opening is changed to have at least one of a different shape, a different position, or a different orientation; Outputting a second screen display to the display, wherein the second screen display; includes an ultrasonic image based on the ultrasonic data; and the model of the opening within the ultrasonic image, wherein the model of the opening in the second screen display includes at least one of the different shape, the different position, or the different orientation; A method comprising. **Claim 12** When executed by a processor, the processor is caused to: Receive ultrasonic data acquired by an array of acoustic elements of an ultrasonic system, wherein the ultrasonic data represents mitral valve regurgitation associated with an opening of a mitral valve, and the ultrasonic data has three-dimensional Doppler data and B-mode data; Generate a three-dimensional model of the mitral valve based on the B-mode data; Generate a model of the opening based on the three-dimensional model of the mitral valve and the three-dimensional Doppler data, wherein the model of the opening has a set of points located on the three-dimensional model of the mitral valve; Output a first screen display to a display, wherein the first screen display; includes the three-dimensional model of the mitral valve; Steps including the model of the opening within the three-dimensional model of the mitral valve; Generating a blood flow model of mitral regurgitation based on the model of the opening by associating each point of the set of points with a flow model of a source point and calculating the blood flow model of mitral regurgitation as a convolution of the flow models associated with each of the set of points; Comparing the blood flow model with the three-dimensional Doppler data; Changing the model of the opening such that the blood flow model is changed to match the three-dimensional Doppler data, wherein the model of the opening is changed to have at least one of a different shape, a different position, or a different orientation; Outputting a second screen display to the display, the second screen display including: An ultrasonic image based on the ultrasonic data; and The model of the opening within the ultrasonic image, wherein the model of the opening within the second screen display includes at least one of the different shape, the different position, or the different orientation; A non-transitory computer-readable medium storing computer-readable instructions for causing the steps to be executed. **Claim 13**: A processor circuit comprising: A processor; A memory; and A communication module wherein the processor, the memory, and the communication module communicate directly or indirectly with each other, and the memory includes the non-transitory computer-readable medium according to claim 12. A processor circuit. ​

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