Steerable multi-plane ultrasound imaging system

Abstract

A steerable multi-plane ultrasound imaging system (MPUIS) for steering a plurality of intersecting image planes (PL 1...n ) of a beamforming ultrasound imaging probe (BUIP) based on ultrasound signals transmitted between the beamforming ultrasound imaging probe (BUIP) and an ultrasound transducer (S) disposed within a field of view (FOV) of the probe (BUIP). An ultrasound tracking system (UTS) adjusts an orientation of the first image plane (PL1) by maximizing an amplitude of ultrasound signals transmitted between the beamforming ultrasound imaging probe (BUIP) and the ultrasound transducer (S) such that a first image plane passes through a location (POS) of the ultrasound transducer (S). An orientation of a second image plane (PL2) is adjusted such that an intersection line (AZ) between the first image plane and the second image plane passes through the location of the ultrasound transducer (S).

Description

Technical Field

[0001] This invention relates to a steerable multiplanar ultrasound imaging system. Related methods and computer program products are also provided. This invention is particularly applicable to the field of medical ultrasound imaging and can be used with a wide variety of ultrasound imaging probes. It is contemplated for use with transthoracic “TTE” ultrasound imaging probes, intravascular “IVUS” ultrasound imaging probes, transesophageal “TEE” ultrasound imaging probes, transnasal “TNE” ultrasound imaging probes, intracardiac “ICE” ultrasound imaging probes, and transrectal “TRUS” ultrasound imaging probes. Background Technology

[0002] Multiplanar ultrasound imaging systems provide medical practitioners with anatomical views to support medical procedures. Compared to single-planar ultrasound imaging, the additional views provided by multiplanar imaging systems offer improved visualization of anatomical structures while avoiding the typically lower resolution or frame rate associated with full 3D imaging.

[0003] In this regard, US 2014 / 013849 A1 discloses a multiplanar ultrasound imaging system. Imaging data is acquired for a first plane and a second plane. The system includes adjusting a first orientation of the first plane and automatically adjusting a second orientation of the second plane to maintain a fixed relationship between the second and first planes. US 2014 / 013849 A1 discloses adjusting the first plane using a user interface.

[0004] This invention addresses the shortcomings of known multiplanar ultrasound imaging systems. Summary of the Invention

[0005] This invention seeks to provide an improved multi-plane ultrasound imaging system. The invention is defined by the claims. Specifically, a steerable multi-plane ultrasound imaging system for steering multiple intersecting image planes of a beamforming ultrasound imaging probe based on an ultrasound signal emitted between the probe and an ultrasound transducer positioned within the probe's field of view includes a beamforming ultrasound imaging probe and an ultrasound tracking system. The beamforming ultrasound imaging probe generates an ultrasound beam defining multiple intersecting image planes, including a first image plane and a second image plane. The ultrasound tracking system causes the beamforming ultrasound imaging probe to adjust the orientation of the first image plane by maximizing the amplitude of the ultrasound signal emitted between the beamforming ultrasound imaging probe and the ultrasound transducer, such that the first image plane passes through the position of the ultrasound transducer. The ultrasound tracking system also causes the beamforming ultrasound imaging probe to adjust the orientation of the second image plane, such that the intersection line between the first and second image planes passes through the position of the ultrasound transducer.

[0006] The position of the ultrasonic transducer is determined by maximizing the amplitude of the ultrasonic signal emitted between the imaging probe and the transducer. This position is then used as a reference position, through which the intersecting lines of the image planes intersect. This method of using the image plane to track the position of the ultrasonic transducer compensates for relative movement between the imaging probe and the target within the field of view, which could cause the target to disappear when it moves out of one or more image planes. Therefore, the system provides a more stable planar image across this position and avoids the drawbacks of lower resolution and / or lower frame rates associated with 3D image processing during imaging of the entire 3D field of view. Further advantages of the invention described herein will also be apparent to those skilled in the art.

[0007] Further aspects are described with reference to the claims. Further advantages of these aspects will also be apparent to those skilled in the art. Attached Figure Description

[0008] Figure 1 The illustration shows a steerable multiplane ultrasound imaging system (MPUIS) including a beamforming ultrasound imaging probe (BUIP) with intersecting image planes PL1 and PL2 within the field of view (FOV).

[0009] Figure 2 Figures 2A-2C The diagram illustrates the adjustment of the image planes PL1 and PL2 of the beamforming ultrasound imaging probe BUIP by tilting each image plane relative to the normal axis NA.

[0010] Figure 3 The illustration shows the adjustment of the image planes PL1 and PL2 of the beamforming ultrasound imaging probe BUIP based on image features detected in image plane PL1.

[0011] Figure 4 The illustration shows the reconstruction of a three-dimensional ultrasound image using the acquired ultrasound image data while rotating image planes PL1 and PL2.

[0012] Figure 5 illustrates the generation of an overlay image in which the reconstructed ultrasound image is registered to the anatomical model AM, and the adjustment of the image plane PL2 to achieve the desired view defined in the anatomical model.

[0013] Figure 6 The diagram illustrates a flowchart of the method MET, which can be used in conjunction with some aspects of this disclosure. Detailed Implementation

[0014] To illustrate the principles of the invention, a steerable multiplanar ultrasound imaging system is specifically described with reference to a beamforming ultrasound imaging probe in the form of a TTE probe. However, it will be appreciated that systems with alternative ultrasound imaging probes are also contemplated, including but not limited to: IVUS ultrasound imaging probes, TEE ultrasound imaging probes, TNE ultrasound imaging probes, ICE ultrasound imaging probes, or TRUS ultrasound imaging probes. Furthermore, the combined use of this system with interventional devices is specifically described with reference to an interventional device as a medical needle. However, it will be appreciated that the combined use of this system with other interventional devices is also contemplated, including but not limited to catheters, guidewires, probes, endoscopes, electrodes, robots, filtering devices, balloon devices, stents, mitral valve clips, left atrial appendage closure devices, aortic valves, pacemakers, venous conduits, drainage conduits, surgical instruments, tissue sealing devices, tissue cutting devices, or implantable devices.

[0015] In response, Figure 1 The illustration depicts a steerable multiplanar ultrasound imaging system (MPUIS) including a beamforming ultrasound imaging probe (BUIP) with intersecting image planes PL1 and PL2 within a field of view (FOV). The MPUIS also includes an ultrasound tracking system (UTS) and may optionally include one or more of the illustrated units: an image reconstruction unit (IRU) that generates reconstructed ultrasound images corresponding to each of the image planes PL1 and PL2; an image registration unit (IREGU) that generates a superimposed image in which the reconstructed ultrasound images are registered to an anatomical model; and a display (DISP) that displays the image and / or anatomical model corresponding to each of the image planes PL1 and PL2. Figure 1 Each unit communicates with the others as indicated by the connecting lines.

[0016] Figure 1 The steerable multiplane ultrasound imaging system (MPUIS) is configured to generate and manipulate multiple intersecting image planes, such as the image planes PL1 and PL2 exemplified by the beamforming ultrasound imaging probe BUIP. Figure 1As shown, image planes PL1 and PL2 intersect transversely. In some embodiments, image planes PL1 and PL2 intersect orthogonally. Each image plane is defined by multiple beams that transmit and receive ultrasound signals (particularly ultrasound imaging signals) within it. Image planes PL1 and PL2 can be redirected (i.e., the orientation of image planes PL1 and PL2 can be adjusted) using beam steering techniques known from the field of ultrasound. Such techniques apply a relative delay to the ultrasound imaging signals transmitted and received by the elements of a two-dimensional array of ultrasound transducer elements of a beamforming ultrasound imaging probe BUIP. Beam steering techniques, for example, those disclosed in document US 2014 / 013849 A1, can be used. The beamforming ultrasound imaging probe BUIP may include electronic circuitry and / or a processor combined with memory, or be controlled by electronic circuitry and / or a processor combined with memory, the processor running instructions stored in memory, and the instructions corresponding to one or more of the aforementioned beamforming and redirecting techniques. Additional image planes, different from the image planes PL1 and PL2 illustrated in these two figures, can be provided and redirected in a similar manner.

[0017] refer to Figure 1 An ultrasonic transducer S is positioned within the field of view (FOV) of a beamforming ultrasonic imaging probe (BUIP). The FOV represents the area within which the BUIP can transmit and receive ultrasonic imaging signals and thereby generate an ultrasonic image. The ultrasonic transducer S can be an ultrasonic sensor, an ultrasonic transmitter, or something that can both sense and transmit ultrasonic signals. Positioning the ultrasonic transducer within the FOV allows the transducer S to receive ultrasonic signals emitted by the BUIP, and / or, conversely, allows the BUIP to receive ultrasonic signals emitted by the transducer S. It is contemplated to use piezoelectric transducers or capacitive micromechanical ultrasonic transducers (i.e., CMUT transducers) for the ultrasonic transducer S. Both rigid and flexible piezoelectric materials are contemplated. In particular, polyvinylidene fluoride (PVDF), also known as polyvinylidene fluoride, can be used, whose mechanical properties and manufacturing processes allow it to adhere to curved surfaces (e.g., medical needles). Alternative piezoelectric materials include PVDF copolymers (e.g., polyvinylidene fluoride-trifluoroethylene) and PVDF terpolymers (e.g., P(VDF-TrFE-CTFE)). Alternatively, other non-piezoelectric materials may be used for the ultrasonic transducer S. In some embodiments, the ultrasonic transducer S may be disposed on an interventional device, which may be, for example, a medical needle or another interventional device. The interventional device may have an elongated axis. The ultrasonic transducer may be wound around the elongated axis of the interventional device to provide ultrasonic sensing and / or emission around the elongated axis, but this is not necessary.

[0018] Figure 1The ultrasonic tracking system (UTS) includes electronic circuitry and / or a processor combined with memory, which executes instructions stored in the memory, and these instructions correspond to the following method steps:

[0019] The beamforming ultrasonic imaging probe BUIP adjusts the orientation of the first image plane PL1 by maximizing the amplitude of the ultrasonic signal emitted between the beamforming ultrasonic imaging probe BUIP and the ultrasonic transducer S, so that the first image plane passes through the position of the ultrasonic transducer S; and

[0020] The orientation of the second image plane PL2 is adjusted by the beamforming ultrasonic imaging probe BUIP so that the intersection line AZ between the first image plane and the second image plane passes through the position of the ultrasonic transducer S.

[0021] Ultimately, the image reconstruction unit (IRU) can generate a reconstructed ultrasound image corresponding to each of the image planes PL1 and PL2, and the display (DISP) can display the image corresponding to each of the image planes PL1 and PL2.

[0022] In some embodiments, the reconstructed images can be displayed as live images, and in other embodiments, the display of the reconstructed images can be synchronized with a specific cardiac or respiratory cycle, and the displayed image data is only for a predetermined phase of the cycle. This cardiac “gating” can, for example, be used to “freeze” the mitral valve in successive open or closed states, thereby allowing medical practitioners to focus on specific parts of the anatomical structure. It is contemplated to use image-based segmentation or cardiac / respiratory sensor data received from sensors such as electrocardiogram sensors (i.e., ECG sensors), ultrasound sensors, strain sensors, cameras, or motion sensors to determine the relevant cycle. The paper “An open-source real-time ultrasound reconstruction system for four-dimensional imaging of moving organs” by Pace, D et al. (http: / / hdl.handle.net / 10380 / 3083) provides an example of 4D ultrasound for reconstructing 3D volumes using ECG gating. Therefore, in this embodiment, Figure 1 The ultrasound tracking system (UTS) may include an image reconstruction unit (IRU) and a display (DISP). The IRU is configured to generate reconstructed ultrasound images corresponding to each of image planes PL1 and PL2, and the DISP displays the images corresponding to each of image planes PL1 and PL2. Electronic circuitry and / or related... Figure 1The processor of the memory assembly of the ultrasound tracking system (UTS) can also be configured to run instructions stored in the memory, which correspond to the following method steps: receiving cardiac cycle data or respiratory cycle data corresponding to an object within the field of view (FOV) of the probe (BUIP), identifying a predetermined phase within the cycle data, and gate the display of the reconstructed ultrasound image such that only the image corresponding to each of the image planes PL1 and PL2 at the predetermined phase of the cycle is displayed.

[0023] In operation, the orientation of the first and second image planes can be adjusted, for example, by tilting, rotating, or translating the image planes. The beamforming ultrasound imaging probe BUIP may include a two-dimensional array of transducer elements having an orthogonal axis NA, and adjusting the orientation of the first image plane PL1 or the second image plane PL2 may include at least one of the following: i) tilting the respective image planes PL1 and PL2 relative to the orthogonal axis NA, ii) rotating the respective image planes PL1 and PL2 about the orthogonal axis NA, and iii) translating the respective image planes PL1 and PL2 perpendicularly relative to the orthogonal axis NA.

[0024] Figure 2 shows an example of adjusting image planes PL1 and PL2 according to the above method steps. Figures 2A-2C The diagram illustrates the adjustment of image planes PL1 and PL2 of the beamforming ultrasound imaging probe BUIP by adjusting each image plane relative to the orthogonal axis NA. Figure 2A In the image, the intersection line AZ between the first image plane PL1 and the second image plane PL2 does not initially cross the position POS of the ultrasonic transducer S. This can be considered as representing the initial arrangement before tracking the position of the transducer S. Then, as... Figure 2A As indicated by the arrow in the image, by tilting the first image plane PL1 until... Figure 2B The first image plane PL1 is adjusted by positioning it across the ultrasonic transducer S, as indicated in the diagram. This is achieved by maximizing the amplitude of the ultrasonic signal emitted between the beamforming ultrasonic imaging probe BUIP and the ultrasonic transducer S. Figure 2B As indicated, the in-plane position POS1 is therefore identified in the first image plane PL1. To ensure that the intersection line AZ between the first image plane PL1 and the second image plane PL2 passes through the position of the ultrasonic transducer, as shown in... Figure 2B The image plane PL2 is tilted as indicated by the arrow in the image to provide a more accurate representation of the image. Figure 2C The arrangement is as indicated in the diagram, where the intersecting line AZ passes through the location of the ultrasonic transducer. For example, in... Figure 2C As indicated in the diagram, the in-plane position POS2 can be identified on the second image plane PL2, and POS2 coincides with POS1.

[0025] Subsequently, the amplitude of the ultrasonic signal emitted between the beamforming ultrasonic imaging probe BUIP and the ultrasonic transducer S was continuously measured, and the image planes PL1 and PL2 were continuously adjusted in the same manner so that the intersection line of the image planes PL1 and PL2 continued to intersect with the subsequent position of the ultrasonic transducer S.

[0026] In some embodiments, the ultrasonic transducer S is an ultrasonic sensor, while in other embodiments, the ultrasonic transducer S is an ultrasonic transmitter. Furthermore, the ultrasonic signal can be an ultrasonic imaging signal emitted by a beamforming ultrasonic imaging probe (BUIP), or a dedicated ultrasonic tracking signal not used for imaging purposes. This tracking signal can be a directional beam emitted by the beamforming ultrasonic imaging probe (BUIP) within the field of view (FOV), or an omnidirectional signal emitted by the transducer S. In some embodiments, multiple ultrasonic transmitters or receivers are disposed on the beamforming ultrasonic imaging probe (BUIP), and these transmitters or receivers accordingly transmit or receive ultrasonic tracking signals.

[0027] Therefore, the following are anticipated in this regard: i) the ultrasonic transducer S is an ultrasonic sensor, and the ultrasonic signal is an ultrasonic imaging signal emitted by a beamforming ultrasonic imaging probe BUIP and received by the ultrasonic sensor S; ii) the ultrasonic transducer S is an ultrasonic sensor, and the ultrasonic signal is an ultrasonic tracking signal emitted by the beamforming ultrasonic imaging probe BUIP, the ultrasonic tracking signal being interleaved between the ultrasonic imaging signals, and the ultrasonic tracking signal being received by the ultrasonic sensor S; or iii) the ultrasonic transducer S is an ultrasonic sensor, and the ultrasonic signal is an ultrasonic tracking signal emitted by each of a plurality of ultrasonic transmitters disposed on the beamforming ultrasonic imaging probe BUIP, the ultrasonic tracking signal being received by the ultrasonic sensor S; or iv) the ultrasonic transducer S is an ultrasonic transmitter, and the ultrasonic signal is emitted by the ultrasonic transmitter and received by each of a plurality of ultrasonic receivers disposed on the beamforming ultrasonic imaging probe BUIP.

[0028] The method of adjusting the orientation of the second image plane PL2 of the beamforming ultrasound imaging probe BUIP so that the intersection line AZ between the first and second image planes passes through the position of the ultrasound transducer S can be performed simultaneously with or after the method of adjusting the orientation of the first image plane PL1. This can be achieved based on the position POS of the ultrasound transducer S.

[0029] In some implementations, the first image plane PL1 and the second image plane PL2 are adjusted by the following operations:

[0030] Simultaneously adjust the first image plane PL1 and the second image plane PL2 to maximize the maximum electrical signal generated on the first image plane; and

[0031] The second image plane PL2 is adjusted independently of the first image plane PL1 so that the maximum electrical signal generated on the second image plane PL2 is maximized.

[0032] After adjusting image planes PL1 and PL2 so that the intersection line AZ passes through the ultrasonic transducer S, the ultrasonic tracking system UTS can continue tracking the movement of the ultrasonic transducer S to each of a plurality of new positions by adjusting the orientation of the first image plane PL1 and the second image plane PL2 such that the intersection line AZ between the first image plane PL1 and the second image plane PL2 passes through each new position of the ultrasonic transducer S. To do this, the first image plane PL1 and the second image plane PL2 can be alternately adjusted (i.e., dithered) in the lateral relative directions of their respective planes to search for new positions for which the amplitude of the ultrasonic signal emitted between the beamforming ultrasonic imaging probe BUIP and the ultrasonic transducer S is maximum. This adjustment can be made continuously, periodically, or in response to changes in the amplitude of the ultrasonic signal emitted between the beamforming ultrasonic imaging probe BUIP and the ultrasonic transducer S.

[0033] In some embodiments, the ultrasonic tracking system UTS can track the movement of the ultrasonic transducer S to each of a plurality of new positions by adjusting the orientation of a first image plane PL1 and a second image plane PL2 such that the intersection line AZ between the first image plane PL1 and the second image plane PL2 passes through each new position of the ultrasonic transducer S; and if the amplitude of the ultrasonic signal emitted between the beamforming ultrasonic imaging probe BUIP and the ultrasonic transducer S decreases below a predetermined threshold (which may, for example, indicate an unreliable position or indicate that the ultrasonic transducer has been moved too quickly to an out-of-plane position and cannot be tracked), the ultrasonic tracking system UTS can also cause the beamforming ultrasonic imaging probe BUIP to repeat the following steps:

[0034] The orientation of the first image plane PL1 is adjusted by maximizing the amplitude of the ultrasonic signal emitted between the beamforming ultrasonic imaging probe BUIP and the ultrasonic transducer S, so that the first image plane passes through the position of the ultrasonic transducer S; and

[0035] The orientation of the second image plane PL2 is adjusted by the beamforming ultrasonic imaging probe BUIP so that the intersection line AZ between the first image plane and the second image plane passes through the position of the ultrasonic transducer S.

[0036] By using image planes PL1 and PL2 to track the position POS of the ultrasonic transducer S, a planar image across the position POS is provided, and relative movement between the beamforming ultrasonic imaging probe BUIP and the target within the field of view (FOV) is also compensated. Therefore, a more stable planar image across the position is provided without the drawbacks of lower resolution and / or lower frame rate associated with 3D image processing during imaging of the entire 3D field of view.

[0037] In some implementations... Figure 1 The ultrasonic tracking system UTS in the middle can identify the maximum signal ultrasonic beam B for the first image plane PL1. max The maximum signal ultrasonic beam B max An ultrasonic beam is defined as follows: for the ultrasonic beam, the amplitude of the ultrasonic signal emitted between the beamforming ultrasonic imaging probe BUIP and the ultrasonic transducer S at the first image plane PL1 is the largest. In this embodiment, adjusting the beamforming ultrasonic imaging probe BUIP to the second image plane PL2 such that the intersection line AZ between the first and second image planes passes through the ultrasonic transducer S may include: positioning the second image plane PL2 and the maximum signal ultrasonic beam B... max Intersecting. When an ultrasonic tracking system uses an ultrasonic imaging beam, the maximum signal ultrasonic beam B can be easily identified. max This beam thus provides a simple reference beam with which the second image plane PL2 can be aligned.

[0038] For example, in one embodiment, the ultrasonic transducer S is an ultrasonic sensor, and wherein the ultrasonic signal is transmitted by a beamforming ultrasonic imaging probe BUIP and received by the ultrasonic sensor S. In this case, the ultrasonic tracking system UTS can also be configured as follows:

[0039] Receives an electrical signal generated by the ultrasonic sensor S in response to an ultrasonic signal emitted by the beamforming ultrasonic imaging probe BUIP;

[0040] The system receives a synchronization signal from the beamforming ultrasound imaging probe BUIP, the synchronization signal corresponding to the transmission time of the transmitted ultrasound signal; and

[0041] The maximum signal ultrasonic beam B is identified based on the received electrical signal and the received synchronization signal. max .

[0042] A synchronization signal identifies each beam emitted by the beamforming ultrasound imaging probe BUIP. The amplitudes of the electrical signals generated in response to each emitted beam are compared against a first image plane PL1 to determine which beam has the largest generated electrical signal. The beam with the largest generated electrical signal identifies the beam closest to the position of the sensor S. This beam defines the in-plane angle of the sensor S relative to this plane. Optionally, the time of flight corresponding to the time difference between the generation time of the largest electrical signal and the emission time of the ultrasound signal that generates the largest electrical signal can be additionally calculated to determine the distance (i.e., range) between the sensor S and the beamforming ultrasound imaging probe BUIP. This process enables the determination of the beam in which the sensor S is positioned and / or the range of the sensor S.

[0043] In an alternative ultrasonic tracking system (UTS) (which can be particularly used in embodiments with multiple ultrasonic transmitters or receivers positioned on a beamforming ultrasonic imaging probe BUIP), triangulation can be used to determine the position of the ultrasonic transducer S relative to the beamforming ultrasonic imaging probe BUIP. This tracking system (often referred to as an ultrasonic micro-measurement system) can determine the distance between the respective transmitter / receiver and the transducer S based on the time of flight of the ultrasonic signal between each ultrasonic transmitter / receiver positioned on the beamforming ultrasonic imaging probe BUIP and the ultrasonic transducer S. By using triangulation and the propagation speed of the ultrasonic signal, the position POS of the ultrasonic transducer S in relative angles can be determined using the distances between the ultrasonic transducer S and at least three transmitters / receivers, and optionally, the distance (i.e., range) between the beamforming ultrasonic imaging probe BUIP and the ultrasonic transducer S.

[0044] After adjusting image planes PL1 and PL2 so that the intersection line AZ passes through the ultrasonic transducer S, in some embodiments, the ultrasonic tracking system UTS can further adjust at least one of the first image plane PL1 and the second image plane PL2 based on image features. Image features can be detected in the respective planes, for example, using known image segmentation techniques or known model fitting techniques (e.g., feature-based target segmentation or 3D enhanced model registration). Suitable techniques are disclosed in the paper "3D Ultrasound image segmentation: A Survey" by Mozaffari, MH and Lee, W (https: / / arxiv.org / abs / 1611.09811). This technique simultaneously maintains the intersection line AZ between the first and second image planes in a position passing through the ultrasonic transducer S.

[0045] exist Figure 3The diagram illustrates this situation. Figure 3 The illustration shows the adjustment of image planes PL1 and PL2 of the beamforming ultrasound imaging probe BUIP based on image features detected in image plane PL1. Figure 3 In this example, the image feature is a medical needle NL, which is segmented in image plane PL1. The orientation of image plane PL1 is adjusted by rotating it so that it is parallel to and passes through the longitudinal axis of the medical needle NL, maximizing the segmented area of ​​the medical needle NL. In an alternative implementation, image plane PL1 can be rotated so that it passes perpendicularly through the longitudinal axis of the medical needle NL. Therefore, one or more image planes can be adjusted by maximizing the correspondence between the desired image shape and the segmented shape in that image plane. When the shape is a medical needle, the image plane can be rotated until the segmented shape becomes as close as possible to a circle or a straight line; circles and straight lines are orthogonal to the cross-sectional shape of the medical needle. Similarly, in a similar manner, other intersection angles between the longitudinal axis of the medical needle NL and image plane PL1 can be provided by rotating image plane PL1 until the target cross-sectional shape is provided by segmentation, after which image plane PL1 is adjusted to maintain the target cross-sectional shape. Likewise, image plane PL2 and other planes not actually segmented in the image plane can be rotated. Figure 3 Any other image plane shown, so that the mutual angular relationship between image plane PL1 and the intersecting line AZ remains constant or remains unchanged.

[0046] The terms parallel and perpendicular as used in this document refer to a range of ±5 degrees between perfectly parallel and perfectly perpendicular.

[0047] By maintaining this tracking and also by providing an image plane based on image features, a desired view can be provided. Typically, image features can be portions of anatomical structures, portions of interventional devices with attached ultrasound transducers, or portions of a second interventional device within the field of view of a beamforming ultrasound imaging probe.

[0048] In some implementations, image planes PL1, PL2, and any additional image planes that may exist can be adjusted simultaneously in response to movement of image features, while maintaining a constant intersection angle. This advantageously allows the image planes to intersect, for example, based on anatomical features, while simultaneously keeping the image planes at a reference point (specifically, the position of the ultrasound transducer S). In some instances, the selection of image features can be determined based on user input (e.g., based on user input received from a user interface (including a menu of image features) or based on input in the form of user selection of a portion of the reconstructed image corresponding to image plane PL1).

[0049] In an exemplary embodiment, at least one of the first image plane PL1 and the second image plane PL2 can be adjusted based on image features through the following operations:

[0050] Calculate the value of the image quality metric corresponding to the image features; and

[0051] Adjust at least one of the first image plane PL1 and the second image plane PL2 to maximize the value of the image quality metric.

[0052] Image quality metrics can be, for example, i) the completeness of segmentation of image features in the corresponding image planes PL1, PL2, or ii) the tightness of fit between the segmentation result of the model and the image features. For example, if the image feature is a portion of the aortic valve, the image quality metric can represent completeness, i.e., the intensity and / or continuity of pixels of the segmented annular image feature corresponding to the aortic valve. Here, the annular feature serves as a model of the desired anatomical region. By maximizing the completeness of the segmentation result, the orientation of the first image plane can be adjusted continuously or periodically to maintain the aortic valve with the most complete image in the first image plane. This feature can prove beneficial in applications such as TAVI (transcatheter aortic valve implantation) and other structural interventions. This advantageously prevents situations where the user must constantly adjust the positioning of the imaging probe to achieve the desired view.

[0053] refer to Figure 4 And refer to Figure 1 In some implementations, after adjusting the image planes PL1 and PL2 so that the intersection line AZ passes through the ultrasonic transducer S, the image reconstruction unit IRU can reconstruct a three-dimensional ultrasound image by rotating the image plane PL1. 1...n One or more image planes are used, while maintaining the position of the image plane intersecting with that of the ultrasonic transducer. Figure 4 The diagram illustrates this situation. Figure 4 The illustration shows the reconstruction of a three-dimensional ultrasound image using ultrasound image data acquired simultaneously in rotating image planes PL1 and PL2. Figure 4 In this context, the beamforming ultrasound imaging probe BUIP (which can be used to replace...) Figure 1The items (with the same reference numerals) are illustrated as generating image data for each of the image planes PL1, PL2 (each image plane is indicated by a thick solid line). While keeping the intersection line AZ in place through the sensor S, the two image planes are rotated 90 degrees about the intersection line AZ, and image data is generated and recorded at each of the multiple rotation angles. This image data is then plotted as a three-dimensional image. Alternatively, in such three-dimensional image reconstruction, data from only one plane (e.g., image plane PL1) can be provided and used. For example, data for image plane PL1 can be recorded and plotted while rotating the plane by 180 degrees or another angle. It is also contemplated in this regard to use other numbers of image planes and other rotation angles different from these examples. In some embodiments, some overlays of image data generated at the beginning and end of the rotation may be required to provide redundant overlay image data to match the image data obtained at the beginning and end of the rotation. Therefore, in some embodiments, angles slightly greater than 360° / 2n can be used, where n is the number of image planes.

[0054] Therefore, in this implementation, Figure 1 The steerable multiplane ultrasound imaging system (MPUIS) also includes an image reconstruction unit (IRU) that reconstructs an ultrasound image based on ultrasound image data generated by the beamforming ultrasound imaging probe (BUIP) for each of a plurality of image planes (e.g., image planes PL1, PL2). The ultrasound tracking system (UTS) can also cause the beamforming ultrasound imaging probe (BUIP) to adjust one or more image planes PL1, PL2 by rotating (one or more) the image planes about the intersection line AZ between the first image plane PL1 and the second image plane PL2, and reconstruct a three-dimensional ultrasound image based on ultrasound image data corresponding to at least one of the intersecting image planes during the rotation.

[0055] Refer to Figure 5 and refer to Figure 1 In some embodiments, after image planes PL1 and PL2 have been adjusted so that the intersection line AZ passes through the ultrasound transducer S, at least one of image planes PL1 and PL2 can be adjusted to provide the desired view defined in the anatomical model. In these embodiments, Figure 1 The steerable multiplanar ultrasound imaging system (MPUIS) may include an image reconstruction unit (IRU) and an image registration unit (IREGU), which generates a superimposed image of the reconstructed ultrasound image registered to the anatomical model. In Figure 5, a beamforming ultrasound imaging probe (BUIP) can be used to replace the... Figure 1Items with the same reference numerals are illustrated as generating image data for each of the image planes PL1, PL2 (each image plane is indicated by a thick solid line). Figure 5 also includes an anatomical model AM (represented by a segmented structure within a cube reference frame), which corresponds to an anatomical region within the field of view (FOV). The anatomical model AM can be stored in memory including a library of anatomical models selectable based on user input. Ultrasound images from one or more image planes PL1, PL2 are registered to the anatomical model AM. The image registration unit IREGU generates a stacked image in which (one or more) reconstructed ultrasound images are registered to the anatomical model. Figure 5A and Figure 5B The differences between them are shown in the ultrasound tracking system UTS, which adjusts the image plane PL1 of the beamforming ultrasound imaging probe BUIP to achieve the desired view defined in the anatomical model.

[0056] More in detail, Figure 5A In the diagram, the anatomical model AM (i.e., the segmented structure within the cube reference frame) includes a visualization plane VPL, indicated by dashed lines. The visualization plane VPL can correspond, for example, to a desired image slice of the anatomical structure. An example of such a slice could be an annular plane used for visualization of the mitral valve and annulus during a mitral valve clamping procedure. The visualization plane VPL can be selected by means of user input received via a user input device (e.g., a user-selected plane, i.e., the desired view on the image of the anatomical model). The ultrasound tracking system UTS enables the beamforming ultrasound imaging probe BUIP to provide the desired view VPL by rotating one or more of the image planes PL1 and PL2 about the intersection line AZ of the first image plane PL1 and the second image plane PL2, such that one of the image planes (in this example, image plane PL2) is parallel to the visualization plane VPL. In Figure 5, rotating only image plane PL2 while keeping image plane PL1 unchanged allows the two image planes PL1 and PL2 to rotate alternately, such that one of the planes is parallel to the visualization plane VPL. Therefore, the planes can be rotated so that they maintain a constant angular relationship with each other relative to the intersection line AZ, or alternatively, only one of the image planes PL1 and PL2 can be rotated. One or more additional visualization planes different from the image plane VPL can also be defined on the model, and the image planes PL from the steerable multiplane ultrasound imaging system MPUIS can be... 1...n Other image planes are rotated independently to provide (one or more) of these additional visualization planes.

[0057] Figure 6The diagram illustrates a flowchart of the method MET, which can be used in conjunction with some aspects of this disclosure. The method MET can be used to visualize multiple intersecting image planes PL of the beamforming ultrasound imaging probe BUIP based on ultrasound signals emitted between the beamforming ultrasound imaging probe BUIP and an ultrasound transducer S positioned within the field of view (FOV) of the probe BUIP. 1...n Turning. The MET method can be specifically used for reference. Figure 1 - Any system as depicted in Figure 5. The MET method includes the following steps:

[0058] Generate multiple ultrasound beams from GENB to define multiple intersecting image planes PL 1...n The image plane includes at least a first image plane PL1 and a second image plane PL2;

[0059] The orientation of the first image plane PL1 is adjusted by maximizing the amplitude of the ultrasonic signal emitted between the beamforming ultrasonic imaging probe BUIP and the ultrasonic transducer S, so that the first image plane passes through the position of the ultrasonic transducer S.

[0060] The orientation of the second image plane PL2 is adjusted by the CAUINT beamforming ultrasonic imaging probe BUIP so that the intersection line AZ between the first and second image planes passes through the position of the ultrasonic transducer S.

[0061] This method can be specifically used in the following configuration: where the ultrasonic transducer S is an ultrasonic sensor, and where the ultrasonic signal is transmitted by a beamforming ultrasonic imaging probe BUIP and received by the ultrasonic sensor S. In this configuration, the method may further include the following steps:

[0062] Identify the maximum signal ultrasonic beam B of IDBMAX for the first image plane PL1. max The maximum signal ultrasonic beam B max The ultrasonic beam is as follows: For the ultrasonic beam, the amplitude of the ultrasonic signal emitted between the beamforming ultrasonic imaging probe BUIP and the ultrasonic transducer S, with respect to the first image plane PL1, is the largest; and

[0063] The process of adjusting the second image plane PL2 of the beamforming ultrasonic imaging probe BUIP so that the intersection line AZ between the first image plane and the second image plane passes through the position of the ultrasonic transducer S further includes the following steps:

[0064] Make the CAUBMAX second image plane PL2 and the maximum signal ultrasonic beam B max intersect.

[0065] In addition, the method MET may include one or more additional steps that incorporate the system MPUIS disclosure.

[0066] Any method step disclosed herein may be recorded in the form of instructions that, when run on a processor, cause the processor to perform such method steps. These instructions may be stored on a computer program product. The computer program product may be provided by dedicated hardware and hardware capable of running software in association with appropriate software. When provided by a processor, these functions can be provided by a single dedicated processor, a single shared processor, or multiple independent processors, some of which may be shared. Furthermore, the explicit use of the terms "processor" or "controller" should not be construed as exclusively referring to hardware capable of running software, but may implicitly include, but is not limited to, digital signal processor (DSP) hardware, read-only memory (ROM) for storing software, random access memory (RAM), non-volatile storage devices, etc. Moreover, embodiments of the invention may take the form of a computer program product accessible from a computer-usable or computer-readable storage medium that provides program code for use by or with a computer or any instruction execution system. For the purposes of this description, a computer-usable or computer-readable storage medium can be any of the following devices that can include, store, communicate, propagate, or transmit programs for use with or in connection with an instruction execution system, apparatus, or device. The medium can be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. Examples of computer-readable media include semiconductor or solid-state memory, magnetic tape, removable computer floppy disks, random access memory (RAM), read-only memory (ROM), hard disks, and optical discs. Current examples of optical discs include compressed disc-read-only memory (CD-ROM), compressed disc-read / write (CD-R / W), and Blu-ray. TM And DVDs.

[0067] In summary, a steerable multi-plane ultrasound imaging system has been described for steering multiple intersecting image planes of a beamforming ultrasound imaging probe based on ultrasound signals emitted between the probe and an ultrasound transducer positioned within the probe's field of view. The ultrasound tracking system causes the beamforming ultrasound imaging probe to adjust the orientation of a first image plane by maximizing the amplitude of the ultrasound signal emitted between the probe and the transducer, such that the first image plane passes through the position of the ultrasound transducer. The orientation of a second image plane is adjusted such that the intersection line between the first and second image planes passes through the position of the ultrasound transducer.

[0068] Various embodiments and options have been described with respect to the system, and it is noted that various embodiments can be combined to achieve further beneficial effects. No reference numerals in the claims should be construed as limiting the scope of the invention.

Claims

1. A method for imaging multiple intersecting image planes (PLs) of a beamforming ultrasonic imaging probe (BUIP) based on ultrasonic signals emitted between an ultrasonic transducer (S) disposed within the field of view (FOV) of the probe (BUIP). 1...n A steerable multiplanar ultrasound imaging system (MPUIS) comprising: Beamforming Ultrasonic Imaging Probe (BUIP); as well as Ultrasonic tracking system (UTS); The beamforming ultrasound imaging probe (BUIP) is configured to generate multiple intersecting image planes (PLs). 1...n The ultrasonic beam of the image plane includes at least a first image plane (PL1) and a second image plane (PL2). The ultrasonic tracking system (UTS) communicates with the beamforming ultrasonic imaging probe (BUIP) and is configured to: The beamforming ultrasound imaging probe (BUIP) adjusts the orientation of the first image plane (PL1) by maximizing the amplitude of the ultrasound signal emitted between the beamforming ultrasound imaging probe (BUIP) and the ultrasound transducer (S), such that the first image plane passes through the position (POS) of the ultrasound transducer (S); and The beamforming ultrasound imaging probe (BUIP) is adjusted to align the second image plane (PL2) such that the intersection line (AZ) between the first image plane and the second image plane passes through the position of the ultrasound transducer (S). The ultrasonic tracking system (UTS) is further configured to identify the maximum signal ultrasonic beam (B) directed toward the first image plane (PL1). max The maximum signal ultrasonic beam (B) max The ultrasonic beam is such that the amplitude of the ultrasonic signal emitted between the beamforming ultrasonic imaging probe (BUIP) and the ultrasonic transducer (S) on the first image plane (PL1) is the largest; and The adjustment of the second image plane (PL2) of the beamforming ultrasound imaging probe (BUIP) such that the intersection line (AZ) between the first image plane and the second image plane passes through the position of the ultrasound transducer (S) includes: aligning the second image plane (PL2) with the maximum signal ultrasound beam (B). max )intersect.

2. The system according to claim 1, wherein, i) The ultrasonic transducer (S) is an ultrasonic sensor, and wherein the ultrasonic signal is an ultrasonic imaging signal emitted by the beamforming ultrasonic imaging probe (BUIP) and received by the ultrasonic sensor (S); or ii) The ultrasonic transducer (S) is an ultrasonic sensor, and wherein the ultrasonic signal is an ultrasonic tracking signal emitted by the beamforming ultrasonic imaging probe (BUIP), the ultrasonic tracking signal being interleaved between ultrasonic imaging signals, and the ultrasonic tracking signal being received by the ultrasonic sensor (S); or iii) The ultrasonic transducer (S) is an ultrasonic sensor, and wherein the ultrasonic signal is an ultrasonic imaging signal emitted by the beamforming ultrasonic imaging probe (BUIP) and received by the ultrasonic sensor (S); An ultrasonic tracking signal is emitted by each of a plurality of ultrasonic transmitters on a beamforming ultrasonic imaging probe (BUIP), and the ultrasonic tracking signal is received by the ultrasonic sensor (S); or wherein, iv) the ultrasonic transducer (S) is an ultrasonic transmitter, and wherein the ultrasonic signal is emitted by the ultrasonic transmitter and received by the beamforming ultrasonic imaging probe (BUIP); or wherein, iv) the ultrasonic transducer (S) is an ultrasonic transmitter, and wherein the ultrasonic signal is emitted by the ultrasonic transmitter and received by each of a plurality of ultrasonic receivers disposed on the beamforming ultrasonic imaging probe (BUIP).

3. The system according to claim 1, wherein, The ultrasonic transducer (S) is an ultrasonic sensor, and wherein the ultrasonic signal is emitted by the beamforming ultrasonic imaging probe (BUIP) and received by the ultrasonic sensor (S); and wherein the ultrasonic tracking system (UTS) is further configured to: Receives an electrical signal generated by the ultrasonic sensor (S) in response to the ultrasonic signal emitted by the beamforming ultrasonic imaging probe (BUIP); The system receives a synchronization signal from the beamforming ultrasound imaging probe (BUIP), the synchronization signal corresponding to the transmission time of the transmitted ultrasound signal; and The maximum signal ultrasonic beam (B) is identified based on the received electrical signal and the received synchronization signal. max ).

4. The system according to claim 1, wherein, The beamforming ultrasound imaging probe (BUIP) includes a two-dimensional array of transducer elements having an orthogonal axis (NA), and wherein adjusting the orientation of the first image plane (PL1) or the second image plane (PL2) includes at least one of the following: i) tilting the respective image plane (PL1, PL2) relative to the orthogonal axis (NA), ii) rotating the respective image plane (PL1, PL2) about the orthogonal axis (NA), and iii) translating the respective image plane (PL1, PL2) perpendicularly relative to the orthogonal axis (NA).

5. The system according to claim 1, wherein, The ultrasonic tracking system (UTS) is further configured to track the movement of the ultrasonic transducer (S) to each of a plurality of new positions by: adjusting at least the orientation of the first image plane (PL1) and the second image plane (PL2) such that the intersection line (AZ) between the first image plane (PL1) and the second image plane (PL2) passes through each new position of the ultrasonic transducer (S); and wherein, If the amplitude of the ultrasonic signal transmitted between the beamforming ultrasonic imaging probe (BUIP) and the ultrasonic transducer (S) decreases below a predetermined threshold, the ultrasonic tracking system (UTS) is further configured to cause the beamforming ultrasonic imaging probe (BUIP) to repeat the following steps: The orientation of the first image plane (PL1) is adjusted by maximizing the amplitude of the ultrasonic signal emitted between the beamforming ultrasonic imaging probe (BUIP) and the ultrasonic transducer (S), such that the first image plane passes through the position of the ultrasonic transducer (S); and The beamforming ultrasound imaging probe (BUIP) is adjusted to align the second image plane (PL2) such that the intersection line (AZ) between the first image plane and the second image plane passes through the position of the ultrasound transducer (S).

6. The system according to claim 1, wherein, The ultrasonic tracking system (UTS) is also configured to cause the beamforming ultrasonic imaging probe (BUIP) to adjust at least one of the first image plane (PL1) and the second image plane (PL2) based on image features detected in the respective image planes (PL1, PL2); while keeping the intersection line (AZ) between the first image plane and the second image plane at the position passing through the ultrasonic transducer (S).

7. The system according to claim 6, wherein, The ultrasonic tracking system (UTS) is configured to cause the beamforming ultrasound imaging probe (BUIP) to adjust at least one of the first image plane (PL1) and the second image plane (PL2) based on the image features by the following operations: Calculate the value of the image quality metric corresponding to the image features; and Adjust at least one of the first image plane (PL1) and the second image plane (PL2) to maximize the value of the image quality metric.

8. The system according to claim 7, wherein, Calculating the image quality metric includes: i) segmenting the image features in the corresponding image planes (PL1, PL2), or ii) fitting a model to the image features.

9. The system of claim 1, further comprising an image reconstruction unit (IRU) configured to be based on the beamforming ultrasound imaging probe (BUIP) targeting the image plane (PL). 1...n The ultrasound image is reconstructed by generating ultrasound image data from each image plane in the image plane, and in which, The ultrasonic tracking system (UTS) is further configured to cause the beamforming ultrasonic imaging probe (BUIP) to rotate the plurality of image planes (PL) about the intersection line (AZ) between the first image plane and the second image plane. 1...n To adjust the multiple image planes (PL) 1...n ), and based on the intersecting image planes (PL) during the rotation. 1...n The three-dimensional ultrasound image is reconstructed from ultrasound image data corresponding to at least one intersecting image plane in the image plane.

10. The system of claim 1, further comprising an image reconstruction unit (IRU) configured to be based on the beamforming ultrasound imaging probe directed at the image plane (PL). 1...n The ultrasound image is reconstructed by generating ultrasound image data from each image plane in the image plane. It also includes an image registration unit (IREGU) configured to generate an overlay image, wherein, The reconstructed ultrasound images were registered to the anatomical model (AM); and The ultrasound tracking system (UTS) is configured to adjust the image plane (PL) of the beamforming ultrasound imaging probe (BUIP) based on a desired view defined in the anatomical model (AM). 1...n At least one image plane in ).

11. The system according to claim 10, wherein, The desired view includes a visualization plane (VPL); and wherein the ultrasound tracking system (UTS) is configured to provide the desired view (VPL) by rotating at least one of the image planes about the line of intersection (AZ) of the first image plane (PL1) and the second image plane (PL2) such that at least one of the image planes is parallel to the visualization plane.

12. A method for imaging multiple intersecting image planes (PLs) of a beamforming ultrasonic imaging probe (BUIP) based on ultrasonic signals emitted between a beamforming ultrasonic imaging probe (BUIP) and an ultrasonic transducer (S) disposed within the field of view (FOV) of the probe (BUIP). 1...n Method of Turning (MET), the method comprising the following steps: Generate multiple ultrasonic beams to define multiple intersecting image planes (PLs). 1...n The image plane includes at least a first image plane (PL1) and a second image plane (PL2); The beamforming ultrasound imaging probe (BUIP) adjusts the orientation of the first image plane (PL1) by maximizing the amplitude of the ultrasound signal emitted between the beamforming ultrasound imaging probe (BUIP) and the ultrasound transducer (S), such that the first image plane passes through the position of the ultrasound transducer (S); and The beamforming ultrasound imaging probe (BUIP) is adjusted to align the second image plane (PL2) such that the intersection line (AZ) between the first image plane and the second image plane passes through the position of the ultrasound transducer (S). The method further includes: identifying the maximum signal ultrasonic beam (B) targeting the first image plane (PL1). max The maximum signal ultrasonic beam (B) max The ultrasonic beam is such that the amplitude of the ultrasonic signal emitted between the beamforming ultrasonic imaging probe (BUIP) and the ultrasonic transducer (S) on the first image plane (PL1) is the largest; and The adjustment of the second image plane (PL2) of the beamforming ultrasound imaging probe (BUIP) such that the intersection line (AZ) between the first image plane and the second image plane passes through the position of the ultrasound transducer (S) includes: aligning the second image plane (PL2) with the maximum signal ultrasound beam (B). max )intersect.

13. A computer program product comprising instructions which, when executed on a processor of a system for orienting a plurality of intersecting image planes of a beamforming ultrasound imaging probe based on ultrasound signals detected by an ultrasound sensor positioned within the field of view of the probe, cause the processor to perform the steps of the method according to claim 12.

14. A computer-readable storage medium comprising a computer program product according to claim 13.

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