Generating one or more motion indicators

Abstract

A mechanism for generating one or more indicators regarding movement of a region of interest through a sequence of ultrasound images. A reference position is defined relative to the ultrasound image (250). For each ultrasound image, a region-of-interest distance or relative position with respect to a reference position is identified (230). In response to the determined location of the region of interest, one or more indicators are generated (240). The one or more indicators comprise a cloud of points (310), and each point represents an identified location for a respective ultrasound image in the sequence of ultrasound images. A user perceptible representation of the one or more indicators is provided to a user interface.

Description

Technical Field

[0001] This invention relates to the field of ultrasound imaging, and more particularly to tracking the motion of a region of interest during ultrasound imaging. Background Technology

[0002] Ultrasound imaging is a commonly used technique for generating medical image data of regions of interest (ROIs) of objects, such as medical subjects. Specifically, ultrasound imaging is one of the most widely used techniques for monitoring fetal growth within the uterus. Unlike computed tomography (CT) or magnetic resonance (MR) imaging techniques, which require large, bulky machines, ultrasound imaging can be performed using handheld devices. This portability provides ultrasound imaging equipment with significant flexibility in use compared to other medical imaging modalities.

[0003] However, since ultrasound imaging is typically performed using handheld devices (such as handheld ultrasound transducers), the quality of any resulting ultrasound images will depend heavily on the operator's handling of the handheld device. In particular, even slight deviations in the transducer can cause significant differences in the image's viewing plane.

[0004] From an image quality perspective, another issue with fetal monitoring is the movement of the fetus within the uterus. This movement can create "echoes" in any generated ultrasound images, or even result in a completely different view, requiring the user to readjust the probe position.

[0005] Therefore, reliable and interpretable information about the movement of the region of interest relative to the ultrasound equipment has been desired. This movement may be caused by the movement of the ultrasound equipment, the monitored object, or the region of interest within the monitored object. Summary of the Invention

[0006] This invention is defined by the claims.

[0007] According to one aspect of the present invention, a computer-implemented method is provided for outputting one or more indicators of movement of a region of interest in a sequence of ultrasound images of an object.

[0008] The computer-implemented method includes: obtaining the sequence of ultrasound images of an object; processing the ultrasound images for each ultrasound image in the sequence to identify the location of a region of interest (ROI) in the ultrasound images; performing an ROI characterization process for each ultrasound image in the sequence, the ROI characterization process including determining the relative position of the identified location of the ROI with respect to the reference position; outputting one or more indicators in response to the determined relative position for each ultrasound image, the one or more indicators including a point cloud, each point representing the identified location for the corresponding ultrasound image in the sequence of ultrasound images; and controlling a user interface to provide a user-perceptible representation of the one or more indicators.

[0009] This disclosure thus provides an apparatus for providing an indicator of movement of a region of interest (ROI) in a sequence of ultrasound images. Specifically, information about the movement relative to a reference position is output, for example, for display and / or further processing. In particular, the output point cloud illustrates the position of the ROI relative to the reference point across image frames, thereby illustrating the distribution of the movement of the ROI in the ultrasound image sequence. Optionally, the point cloud may be centered on the reference position. In some embodiments, the point cloud is plotted in polar coordinates, forming a radial or radar-type map.

[0010] It will be clear that the reference position is a non-origin location for each ultrasound image; that is, it is not located at the origin of the Euclidean or Cartesian coordinate system that defines the position within each ultrasound image. To avoid ambiguity, it should be noted that the reference position is the same for all ultrasound images in the sequence.

[0011] In some examples, the ROI characterization process includes determining at least one direction between a reference location and an identified location of the region of interest. In some examples, the ROI characterization process includes determining the distance and direction between the reference location and the identified location of the region of interest.

[0012] In some examples, the output of one or more indicators also includes defining attributes for each point in the point cloud in response to the position of a corresponding ultrasound image in the sequence of ultrasound images. Optionally, the attributes may advantageously include at least one of the following: opacity, color, intensity, size, shape, and pattern.

[0013] In some examples, the reference location is the average location of the region of interest across the sequence of ultrasound images. This helps to provide easily interpretable information about the deviation of the region of interest from the mean point, thus providing more useful information about the stability of the position of the region of interest across the sequence of ultrasound images.

[0014] In other examples, the reference location is the centroid of the ultrasound image; or it is located at a predetermined offset from the centroid of the ultrasound image. Generally, it is preferred to keep the region of interest at the centroid of the ultrasound image—because this represents the center of incidence of the sound waves during ultrasound imaging. By defining the reference location at the centroid of the ultrasound image, deviations from this preferred location can be quickly and easily identified. Using such a reference location also facilitates the real-time determination of the distance, orientation, and / or relative position of the region of interest relative to the reference location.

[0015] In some examples, for each ultrasound image, the reference location is the average location of the region of interest across the sequence of ultrasound images. The computer-implemented method further includes processing the identified location of the region of interest in each ultrasound image to determine the average location of the region of interest across the sequence of ultrasound images.

[0016] In some examples, the reference location is the mode mean location of the region of interest across the sequence of ultrasound images. This provides an indication of deviation or movement of the region of interest from its most common location, for example, to draw closer attention to sudden spikes or shifts in the region of interest.

[0017] The ROI characterization process may include determining the distance and / or direction between the reference location and the identified location of the region of interest.

[0018] In such an example, the step of outputting one or more indicators may include outputting a point cloud in response to a determined distance and / or direction.

[0019] In some such examples, the ROI characterization process includes determining an average distance between the reference location and the identified location of the region of interest across the sequence of ultrasound images by processing determined distances and / or orientations for each ultrasound image in the sequence, and the step of outputting one or more indicators includes outputting indicators in response to the determined average distance. This provides information about the distance the region of interest has moved, which provides valuable guidance for the operator of the ultrasound imaging system and / or the interpretation of the sequence of ultrasound images (e.g., because the movement may represent a clinically important parameter to be considered). The ROI characterization process may additionally include: determining an average orientation between the reference location and the identified location of the region of interest by processing determined orientations for each ultrasound image in the sequence; and in the step of outputting one or more indicators, the indicators may also respond to the determined average orientation.

[0020] In some examples, the step of determining the distance between the reference location and the identified location of the region of interest during the ROI characterization process includes using the Pythagorean theorem to determine the distance between the reference location and the identified location of the region of interest. This provides an efficient method for determining the distance between two locations.

[0021] The ROI characterization process may include determining the orientation between the reference location and the identified location of the region of interest.

[0022] The step of outputting one or more indicators may include: determining an average direction by processing a determined direction for each ultrasound image in the sequence, and outputting a direction indicator in response to the determined average direction. The average direction is preferably a mean-averaged direction. This method helps to provide guidance to operators of ultrasound imaging systems or reviewers of the sequence of ultrasound images regarding the movement of a region of interest (ROI), and therefore, how to compensate for or account for this movement, for example, in further ultrasound imaging and / or analysis of the sequence of ultrasound images.

[0023] Optionally, in the ROI characterization process, the step of determining the orientation between the reference location and the identified location of the region of interest may include using a triangulation process to determine the orientation between the reference location and the identified location of the region of interest.

[0024] The ROI characterization process may include determining the relative position of the identified location of the region of interest with respect to a reference location in a polar coordinate system.

[0025] In some examples, the ROI characterization process includes determining the distance and orientation between the reference location and the identified location of the region of interest; and in the ROI characterization process, the step of determining the relative position of the identified location of the region of interest with respect to the reference location in a polar coordinate system includes processing the determined distance and orientation to generate polar coordinates of the identified location in the polar coordinate system.

[0026] In some examples, the identified location and reference location of the region of interest are defined using Cartesian coordinates in a Cartesian coordinate system; and in the ROI characterization process, the step of determining the relative position of the identified location of the region of interest with respect to the reference location in a polar coordinate system includes: generating a quotient for each dimension of the Cartesian coordinate system by dividing the value of the identified location by the value of the reference location; and multiplying the quotient by the maximum possible value relative to the Cartesian coordinate dimension of the ultrasound image.

[0027] A computer program product comprising computer program code is also proposed, which, when executed on a computing device having a processing system, causes the processing system to perform all the steps of any of the methods disclosed herein.

[0028] A processing system is also proposed for outputting one or more indicators of movement of a region of interest (ROI) in the sequence of ultrasound images of an object. The processing system is configured to perform the methods described above, namely: obtaining the sequence of ultrasound images of the object; processing the ultrasound images for each image in the sequence to identify the location of the ROI in the ultrasound images; performing an ROI characterization process for each ultrasound image in the sequence, the ROI characterization process including determining the relative position of the identified location of the ROI relative to a reference location; outputting one or more indicators in response to the determined relative position for each ultrasound image, the one or more indicators comprising a point cloud, each point representing the identified location for a corresponding ultrasound image in the sequence of ultrasound images; and controlling a user interface to provide a user-perceptible representation of the one or more indicators.

[0029] Optionally, for each ultrasound image, the reference location is one of the following: the average location of the region of interest across the sequence of ultrasound images; the centroid of the ultrasound images; and / or a location positioned at a predetermined offset from the centroid of the ultrasound images.

[0030] A user interface system is also proposed, comprising a processing system and a user interface. The processing system is configured to control the user interface to provide a user-perceptible representation (e.g., a display) of the one or more indicators. This method advantageously provides information about movement of the region of interest to the ultrasound system operator and / or the sequence analyst of the ultrasound images.

[0031] An ultrasound imaging system is also proposed, comprising an ultrasound transducer configured to generate the sequence of ultrasound images of an object, and a processing system disclosed herein. In some examples, the imaging system includes a user interface system (wherein the processing system forms part of the user interface system).

[0032] These and other aspects of the invention will become apparent and will be explained with reference to the embodiments described below. Attached Figure Description

[0033] To better understand the invention and to more clearly illustrate how it can be practiced, reference will now be made to the accompanying drawings by way of example only, wherein,

[0034] Figure 1 The imaging system is illustrated.

[0035] Figure 2 This is a flowchart of the method proposed in the diagram;

[0036] Figure 3The diagram illustrates the display of the indicators;

[0037] Figure 4 Another display of the indicator is illustrated; and

[0038] Figure 5 The diagram illustrates the processing system. Detailed Implementation

[0039] The invention will be described with reference to the accompanying drawings.

[0040] It should be understood that while the detailed description and specific examples indicate exemplary embodiments of the devices, systems, and methods, they are intended for illustrative purposes only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the devices, systems, and methods of the present invention will be better understood from the following description, the appended claims, and the accompanying drawings. It should be understood that the drawings are schematic only and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the drawings to denote the same or similar parts.

[0041] This invention provides a mechanism for generating one or more indicators relating to a sequence of ultrasound images as a region of interest moves through them. A reference position is defined relative to the ultrasound images. For each ultrasound image, the relative position, orientation, and / or distance of the region of interest relative to the reference position is identified. In response to the determined position, orientation, and / or distance of the region of interest, one or more indicators are generated.

[0042] Figure 1 An ultrasound imaging system 10 is illustrated, in which the proposed embodiment can be employed. The imaging system 10 includes an ultrasound transducer system 190 (e.g., an ultrasound transducer), a processing system 100, and an (optional) user interface 110. The processing system itself is an embodiment of the proposed method.

[0043] The ultrasonic transducer system 190 is configured to perform an ultrasonic imaging procedure on an object 199 to generate a sequence 150 of ultrasonic images. Methods for performing ultrasonic imaging procedures to generate such a sequence of ultrasonic images are well known in the art and will not be described further for the sake of brevity. Each ultrasonic image is a multidimensional image (e.g., a 2D or 3D image) that includes a representation of a portion of the object detected using ultrasound.

[0044] A sequence of ultrasound images can include a time series, where each successive ultrasound image is captured as, or represents, a later time point / time period relative to an earlier ultrasound image in the sequence. However, this is not necessary, and other forms of sequences will be apparent. For example, the sequence can be a spatial sequence, where each successive ultrasound image represents a different location or imaging region.

[0045] In the context of this disclosure, ultrasound images contain only a representation of the imaged portion of an object. In practice, ultrasound images may include additional information (e.g., scale information, object, etc.).

[0046] The processing system 100 is configured to output one or more indicators for movement of a region of interest in the sequence 150 of ultrasound images. For example, the one or more indicators can be used to control the user interface 110, such as providing a visual representation of the one or more indicators.

[0047] Processing system 100 is configured to acquire a sequence 150 of ultrasound images. Sequence 150 may be obtained directly from ultrasound transducer system 190 or from database 196, which is itself configured to receive sequence 150 from ultrasound transducer system 190. Other methods for retrieving or acquiring sequences of ultrasound images will be readily apparent to a skilled technician.

[0048] Figure 2 The flowchart illustrates a computer-implemented method 200 for outputting one or more indicators of movement of a region of interest in the sequence of ultrasound images of an object. Method 200 may be executed, for example, by a processing system 100.

[0049] Method 200 includes step 210, namely obtaining the sequence of ultrasound images of the object. As previously described, this can be performed by obtaining the sequence from an ultrasound transducer system and / or a database.

[0050] Method 200 further includes step 220, which involves processing the ultrasound images for each image in the sequence to identify the location of the region of interest in the ultrasound images. In other words, step 220 includes locating the region of interest in each ultrasound image.

[0051] In step 220, a set of coordinates (e.g., Euclidean or Cartesian coordinates) can be used to define the location of the region of interest. Specifically, a single set of coordinates (each coordinate representing a position along a different dimension) can define the location of the region of interest in Euclidean space.

[0052] The region of interest (ROI) is identical for each ultrasound image in the sequence and, for example, may contain specific anatomical structures (e.g., organs), features, and / or landmarks. The specific nature of the ROI can depend on the application or use case scenario. For example, if the sequence of ultrasound images contains a representation of a fetus, then the ROI could be the fetus. If the sequence of ultrasound images contains images of the chest, then the ROI might be anatomical landmarks of the heart. Other examples of ROI include the femur (e.g., the femur of a fetus), the head (e.g., the head of a fetus), growths such as cancerous hyperplasia, infection, the entrance or exit of a vein or artery, one or more landmarks of the heart, (kidney) stones, vertebrae, and so on.

[0053] Methods for processing ultrasound images to identify the location of regions of interest (ROIs) are well-known and include any suitable localization techniques. One example of a localization technique is a landmark detection technique, which identifies the (individual) location of anatomical landmarks. Another example of a localization technique is using region identification techniques to identify the boundaries or regions occupied by the ROI, and then defining a location within those boundaries or regions (e.g., centroid or angular location) as the location of the ROI. Examples of region identification techniques include image segmentation techniques (e.g., for identifying the boundaries of ROIs) or pixel or pixel region classification techniques (e.g., for identifying pixels containing ROIs, and thus identifying the location of the ROI). Appropriate techniques can also be referred to as localization techniques.

[0054] Several techniques suitable for performing localization are known in the art, for example, as described in one or more of the following publications: Noble, J. Alison, and Djamal Boukerroui. "Ultrasound image segmentation: asurvey." IEEE Transactions on medical imaging 25.8 (2006): 987-1010; Wang, Ziyang. "Deep learning in medical ultrasound image segmentation: A review." arXiv preprint arXiv:2002.07703 (2020); Fiorentino, Maria Chiara, et al. "Areview on deep-learning algorithms for fetal ultrasound-image analysis." Medical Image Analysis (2022): 102629; Liu, Shengfeng, et al. "Deep learning in medical ultrasound analysis: a review." Engineering 5.2 (2019): 261-275; Meiburger, Kristen M., U. Rajendra Acharya, and Filippo Molinari. "Automated localization and segmentation techniques for B-mode ultrasound images: Areview." Computers in biology and medicine 92 (2018): 210-235.

[0055] Specifically, object detection technology is used to identify portions of an ultrasound image that represent a specific object, i.e., predicting bounding boxes or contours that contain and contact the boundaries of the representation of the object in the ultrasound image. Therefore, the object may be a region of interest. The location of the object can be determined as a corner or vertex of the identified bounding box or contour.

[0056] A suitable object detection technique is the "You Only Look Once" (YOLO) algorithm, which was initially proposed by Redmon, Joseph, et al.: "You Only Look Once: Unified, Real-Time Object Detection." Proceedings of the IEEE conference on computer vision and pattern recognition. 2016. The YOLO algorithm has since been further developed, for example, as described by Jiang, Peiyuan, et al. in "A Review of Yolo algorithm developments." Procedia Computer Science 199 (2022): 1066-1073.

[0057] Other suitable object detection techniques will be apparent to those skilled in the art.

[0058] Some embodiments for locating regions of interest can utilize previously determined locations of the region of interest in previous ultrasound images within the sequence of ultrasound images, for example, to effectively track the location of the region of interest within the image sequence. These methods are well-established in the art.

[0059] The method further includes performing a ROI characterization process 230 for each ultrasound image in the sequence. The ROI characterization process 230 includes performing steps 231 and / or 232. Therefore, one or both of steps 231 and 232 can be performed.

[0060] Step 231 includes determining the distance and / or direction between the reference location and the identified location of the region of interest. Step 232 includes determining the relative position of the identified location of the region of interest relative to the reference location. The relative position can take various forms. In one embodiment, it takes the form of the coordinate difference between the reference location and the identified location of the region of interest. In another embodiment, the relative position can be represented by the distance and direction of the identified location of the region of interest relative to the reference location.

[0061] For example, a reference location might be the average location of the region of interest across the sequence of ultrasound images; the centroid of the ultrasound images; and / or a location positioned at a predetermined offset from the centroid of the ultrasound images. A reference location is a non-origin location of the ultrasound images.

[0062] For example, the mean location might be an arithmetic mean. Methods for determining the arithmetic mean location will be readily apparent to those skilled in the art. For instance, if the location of the region of interest is defined by x-coordinates and y-coordinates (e.g., identifying the center or predetermined angle / vertices of the region of interest), the mean location can be determined by averaging all x-coordinate values ​​(here: summing and then dividing by the total number of ultrasound images) to determine the x-coordinate of the mean location of the region of interest, and by averaging all y-coordinate values ​​(here: summing and then dividing by the total number of ultrasound images) to determine the y-coordinate of the mean location of the region of interest.

[0063] For example, the mean location could be the mode mean location. The mode mean location refers to the most frequent location among all (one or more) regions of interest locations across the sequence of ultrasound images.

[0064] Method 200 further includes step 240, which involves outputting one or more indicators (if applicable) in response to a determined distance, orientation, and / or relative position for each ultrasound image. For example, step 240 may include controlling a user interface to provide user-perceptible output (e.g., a display) of the one or more indicators. The user-perceptible output may be a visual representation of the one or more indicators. In some examples, step 240 includes storing the indicators(s) in a database or other storage unit, for example, for later retrieval and / or reference. In still other examples, step 240 may include providing the indicators(s) to a further processing system for further processing.

[0065] The identified indicators(s) can be effectively used as quality indicators of ultrasound sequences for use by operators of further processing systems or algorithms and / or ultrasound transducer systems (e.g., to facilitate decisions on whether to repeat imaging).

[0066] In an embodiment, process 230 includes step 231, which involves determining the distance (i.e., a distance metric) between the reference location and the identified location of the region of interest.

[0067] This can be performed by determining the (shortest) distance between the reference position and the identified position of the region of interest using the Pythagorean theorem. Formula (1) defines a distance D between the reference position and the identified position in a two-dimensional image. 像素（p,q） The appropriate method:

[0068] Here, p represents the pixel at the reference position, and q represents the pixel at the identified position. Each pixel is represented by a corresponding pair of coordinates, for example, representing the position along the x-axis and y-axis. Therefore, p1 represents the position of the pixel at the reference position along the x-axis, p2 represents the position of the pixel at the reference position along the y-axis, and q1 represents the position of the pixel at the identified position along the x-axis and y-axis, respectively.

[0069] Formula (1) defines distance as a metric of pixel distance. This can be achieved by dividing the distance D... 像素（p,q） Multiplying this distance by the known pixel pitch PS converts it to a true distance or spatial distance (e.g., measured in cm, mm, or inches), where PS represents the true distance between the locations represented by the centroids of two adjacent pixels. Therefore, the true distance D... 真实 Formula (2) can be used to calculate:

[0070] The process described above effectively defines a mechanism for determining the Euclidean distance between the identified location (of the ROI in an ultrasound image) and a reference location. However, other suitable distance metrics, such as Manhattan distance or Minkowski distance, can also be used alternatively.

[0071] The distance D can be normalized, for example, to the maximum possible distance of movement of the region of interest in the ultrasound image, which will depend on the size and / or resolution of the ultrasound image.

[0072] In some examples, step 240 includes determining an average distance by processing a defined distance for each ultrasound image in the sequence, and outputting a distance indicator in response to the determined average distance. Determining the average distance preferably includes determining a mean distance. Specifically, the distance indicator itself may be the determined average distance itself.

[0073] This embodiment is particularly advantageous when the reference location is the average location (e.g., mode or mean location) of the region of interest across the sequence of ultrasound images. This is because the average distance will provide useful information about the deviation or movement of the region of interest relative to the center, which can significantly affect the accuracy or interpretability of the sequence of the region of interest across the ultrasound images.

[0074] In some examples, step 240 includes determining a weighted average distance by applying weights to each defined distance of the ultrasound image (e.g., multiplying the distance by a weight value), and then determining a mean average of the weighted distances. A distance indicator can then be output in response to the determined weighted average distance.

[0075] Applying weights can include increasing the weight value for distances to later ultrasound images in the sequence (e.g., captured at a later time point). This gives greater emphasis to the most recent location of the region of interest, which will be more relevant or meaningful to the operator or subsequent processor. In some cases, the weight value for distances to earlier ultrasound images in the sequence may be reduced to zero, effectively creating a time-window average of the determined distances.

[0076] Average distance or weighted average distance is particularly suitable as a quality indicator or metric for ultrasound imaging that generates ultrasound imaging sequences. Therefore, the (weighted) average distance can be output for use by further processing systems or algorithms, and / or displayed to the operator of the ultrasound transducer system (e.g., to facilitate decisions about whether to repeat imaging).

[0077] In one embodiment, the ROI characterization process includes determining the direction between the reference location and the identified location of the region of interest. The direction can be defined with respect to the angle from the reference location to the identified location.

[0078] This can be performed using a triangulation process to determine the direction between the reference position and the identified position in the region of interest. Equation (3) illustrates one method for determining the direction θ from the reference position to the identified position in a two-dimensional image:

[0079] The definitions of p1, p2, q1, and q2 are the same as those described previously.

[0080] In some examples, step 240 includes determining an average direction by processing a determined orientation for each ultrasound image in the sequence, and outputting a direction indicator in response to the determined average direction. Determining the average direction preferably includes determining the mean direction. Specifically, the direction indicator may be the determined average direction itself.

[0081] This embodiment is particularly advantageous when the reference location is the average location (e.g., mode or mean location) of the region of interest across the sequence of ultrasound images. This is because the averaging direction will provide useful information about the deviation or movement of the region of interest relative to the center, which can significantly affect the accuracy or interpretability of the sequence of the region of interest across the ultrasound images.

[0082] In some examples, step 240 includes determining the weighted average direction. This can be done by multiplying each determined distance by a corresponding non-negative weighting value to produce a weighted sum of determined distances. The sum of the weighted determined distances can then be divided by the sum of the non-negative integer weighting values ​​to generate the weighted average direction. Step 240 can then output a direction indicator in response to the determined weighted average direction.

[0083] Mathematically, the weighted average direction θ wav The following formula can be used to calculate:

[0084] Where, θ i x is the defined orientation of the i-th ultrasound image in the sequence, N is the number of ultrasound images in the sequence, and x i It is the non-negative weighting value of the i-th ultrasound image.

[0085] Weighted value x i The weighting value for distances to later ultrasound images in the sequence (e.g., ultrasound images captured at a later time point) may be increased. This gives greater emphasis to the most recent location of the region of interest, which will be more relevant or meaningful to the operator or subsequent processor. In some cases, the weighting value for distances to earlier ultrasound images in the sequence may be reduced to zero, thus effectively creating a time-window average of the determined distances.

[0086] The average direction or weighted average direction is particularly suitable as a quality indicator or metric for ultrasound imaging in the generation of ultrasound imaging sequences. Therefore, the (weighted) average direction can be output for use by further processing systems or algorithms, and / or displayed to the operator of the ultrasound transducer system (e.g., to facilitate decisions about whether to repeat imaging).

[0087] In one embodiment, the ROI characterization process includes determining the relative position of the identified location of the region of interest with respect to a reference location in a polar coordinate system. Each identified relative position can be defined with a corresponding indicator to be output or used to control the output.

[0088] One method for determining this relative position is to use previously disclosed techniques to determine the direction and distance of the identified location from a reference position for each ultrasound image. This defines the relative position in a polar coordinate system.

[0089] Another approach is to directly convert the location of the ROI (e.g., defined as coordinates in Euclidean space) to its location in polar coordinates (x, y, x). n , y n This can be done, for example, by formula (5):

[0090] Where H and W are the height and width of the ultrasound image, respectively, and the definitions of p1, p2, q1, and q2 are the same as those described previously.

[0091] Therefore, in this method, the step of determining the relative position of the identified location of the region of interest with respect to the reference location in the polar coordinate system includes: generating a quotient for each dimension of the Cartesian coordinate system by dividing the value of the identified location by the value of the reference location; and multiplying the quotient by the maximum possible value relative to the Cartesian coordinate dimension of the ultrasound image.

[0092] In some examples, step 240 includes controlling the user interface to display a defined relative position in a polar coordinate system. This provides the operator with a useful and easily interpretable graph to understand the amount and trend or direction of movement. Specifically, the display provides information about any direction of movement of the region of interest.

[0093] In some examples, step 240 is configured to define attributes for the relative position of each display in response to the position of the corresponding ultrasound images in the sequence of ultrasound images. For example, the display of a relative position associated with a later ultrasound image in the sequence can be controlled to be displayed more prominently than the display of a relative position associated with an earlier ultrasound image in the sequence (e.g., greater display intensity, greater opacity, or larger). Thus, as new points become available, the display of older points gradually fades away. Examples of suitable attributes for displaying relative positions include: opacity; color; intensity; size; shape; pattern, etc.

[0094] In some examples, step 240 includes determining a best-fit line or trend for the relative position in the polar coordinate system. This best-fit line or trend provides useful information about the amount and / or overall direction of movement of the region of interest, helping to guide the operator of the ultrasound transducer system to compensate for or correct for this movement during future imaging procedures. It should be understood that the best-fit line or trend will be along or defined by the average direction from the reference point to the region of interest.

[0095] In a simple embodiment, known or existing plotting techniques can be used to determine the best-fit line, for example, using the method proposed by Pearson, Karl. "LIII. On lines and planes of closest fit to systems of points in space." The London, Edinburgh, and Dublin philosophical magazine and journal of science 2.11 (1901): 559-572; or Bland, JA "A line of best fit." International Journal of Mathematical Education in Science and Technology 16.5 (1985): 589-592.

[0096] In an alternative embodiment, the best-fit line can be determined by using the average direction of the location of interest from the reference location. Specifically, the ROI characterization process may include determining the direction between the reference location and the identified location of the region of interest, for example, using formula (3). The determined direction can then be averaged (e.g., a mean can be determined) to determine the average direction from the reference location to the location of interest.

[0097] In some examples, the averaging direction is a weighted average direction, where the method for determining the weighted average direction has been previously identified.

[0098] In some examples, the length of the best-fit line responds to a predetermined (weighted) average distance, for example, increasing as the distance increases. This provides a visual indicator of the (weighted) average distance to the region of interest.

[0099] Figure 3 The illustration shows an example display 300 provided by a user interface, generated by an embodiment of a method for determining the relative position of an identified region of interest location with respect to a reference location.

[0100] Display 300 provides a display of the identified locations of the region of interest (relative to the reference location) defined in a polar coordinate system. Therefore, a point cloud 310 exists, where each point represents a different identified location, surrounding a central location representing the reference location.

[0101] Display 300 also provides a display of the trend or best-fit line 330 for the identified locations, i.e., a display of the point cloud. The direction of the trend or best-fit line 330 may be determined using a (weighted) average direction, for example, as described above. The length of the trend or best-fit line 330 may be determined using a (weighted) average distance (e.g., increasing with increasing (weighted) average distance), or it may be predetermined.

[0102] Figure 4 The illustration shows another example display 400 provided by the user interface, generated by an embodiment of a method for determining the relative position of an identified region of interest location with respect to a reference location. The display again shows an illustration of point cloud 410, with each point representing a different identified location. The center of the display represents the reference location. Display 400 also provides a display of the trend or best-fit line 430 of the identified locations, i.e., a display of the point cloud.

[0103] like Figure 3 and Figure 4 As illustrated in the diagram, the size of the trend line or best-fit line 330, 430, may depend on the average distance between each identified location and the reference location. Specifically, the larger the average distance, the larger the trend line or best-fit line will be. Therefore, the display may also provide distance indicators, such as distance indicators calculated according to the previously described method.

[0104] It should be understood that in some examples, method 200 may perform the functions of one or more of the previously disclosed embodiments. Therefore, step 240 may include generating and outputting a distance indicator, a direction indicator, and / or a determined relative position in polar coordinates.

[0105] In the example described above, a reference location was used in the ROI characterization process. As previously mentioned, the reference location can be the average location of the region of interest across the sequence of ultrasound images; the centroid of the ultrasound images; and / or a location positioned at a predetermined offset from the centroid of the ultrasound images.

[0106] Back Figure 2 Method 200 may also include a step 250 of identifying a reference location. For example, this step may be omitted if the reference location is at a known or predetermined location.

[0107] In one example, step 250 includes determining the average location of the region of interest within the sequence of ultrasound images. The average location may be the mean location or the mode location.

[0108] In another example, step 250 includes processing one of the ultrasound images to identify the centroid represented by the fan-beam of the ultrasound imaging process. The identified fan-beam centroid can then be used as a reference location.

[0109] The proposed method can be performed during or after the ultrasound imaging procedure.

[0110] If performed during an ultrasound imaging procedure, it should be understood that the method can be repeated. In this case, it may not be necessary to repeat the steps performed on previously processed (in the sequence) ultrasound images. Instead, the relevant steps of the method can be performed only on newly acquired ultrasound images in the sequence, which can supplement the previously provided output indicators.

[0111] However, in an alternative example, all steps of the method (preferably, except for step 220) are repeated each time the sequence of ultrasound images is updated. This may be necessary, for example, if the reference location is the average location of the region of interest across the sequence of ultrasound images.

[0112] Formulas (1) to (5) are described in the context of two-dimensional images. Those skilled in the art can readily adapt these formulas for higher-dimensional images (e.g., three-dimensional images) where appropriate.

[0113] Technicians will be able to easily develop processing systems for performing any of the methods described herein. Therefore, each step of the flowchart can represent a different action performed by the processing system, and can be executed by the corresponding module of the processing system.

[0114] Figure 5 An example of a suitable processing system 500 is illustrated.

[0115] The various operations discussed above can utilize the capabilities of computer 500. For example, one or more parts of a processing system for outputting one or more indicators for movement of a region of interest can be incorporated into any element, module, application, and / or component discussed herein. In this regard, it should be understood that system functional blocks can run on a single computer or can be distributed across multiple computers and locations (e.g., via an Internet connection).

[0116] Computer 500 includes, but is not limited to, PCs, workstations, laptops, PDAs, handheld devices, servers, storage devices, and so on. Typically, in terms of hardware architecture, computer 500 may include one or more processors 501, memory 502, and one or more I / O devices 507 communicatively coupled via a local interface (not shown). The local interface may be, for example, but not limited to, one or more buses or other wired or wireless connections, as known in the art. The local interface may have additional elements, such as controllers, buffers (caches), drivers, repeaters, and receivers, to enable communication. Furthermore, the local interface may include address, control, and / or data connections to enable appropriate communication between the aforementioned components.

[0117] Processor 501 is a hardware device for running software that can be stored in memory 502. Processor 501 can actually be any custom or commercial processor, central processing unit (CPU), digital signal processor (DSP), or auxiliary processor among several processors associated with computer 500, and processor 501 can be a semiconductor-based microprocessor (in the form of a microchip) or microprocessor.

[0118] Memory 502 may include any or a combination of volatile memory elements (e.g., random access memory (RAM), such as dynamic random access memory (DRAM), static random access memory (SRAM), etc.) and non-volatile memory elements (e.g., ROM, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic tape, optical disc read-only memory (CD-ROM), magnetic disk, floppy disk, cassette, cassette tape, etc.). Furthermore, memory 502 may contain electronic, magnetic, optical, and / or other types of storage media. Note that memory 502 may have a distributed architecture, where various components are geographically separated but accessible by processor 501.

[0119] The software in memory 502 may include one or more individual programs, each including an ordered list of executable instructions for implementing logical functions. According to an exemplary embodiment, the software in memory 502 includes a suitable operating system (O / S) 505, a compiler 504, source code 503, and one or more application programs 506. As shown, application program 506 includes multiple functional components for implementing the features and operations of the exemplary embodiment. Application program 506 of computer 500 may represent various applications, computing units, logic, functional units, processes, operations, virtual entities, and / or modules according to the exemplary embodiment, but application program 506 is not intended as a limitation.

[0120] Operating system 505 controls the execution of other computer programs and provides scheduling, input-output control, file and data management, memory management, communication control, and related services. The inventors envision that application program 506, used to implement the exemplary embodiment, is applicable to all commercially available operating systems.

[0121] Application 506 can be a source program, an executable program (object code), a script, or any other entity that includes a set of instructions to be executed. When it is a source program, the program is typically translated by a compiler (e.g., compiler 504), assembler, interpreter, etc., which may or may not be included in memory 502 to operate correctly with O / S 505. Furthermore, application 506 can be written in an object-oriented programming language with classes of data and methods, or a procedural programming language with routines, subroutines, and / or functions, such as, but not limited to, Python, C, C++, C#, Pascal, BASIC, API calls, HTML, XHTML, XML, ASP scripts, JavaScript, FORTRAN, COBOL, Perl, Java, ADA, .NET, etc.

[0122] I / O device 507 may include input devices, such as, but not limited to, a mouse, keyboard, scanner, microphone, camera, etc. Furthermore, I / O device 507 may also include output devices, such as, but not limited to, a printer, monitor, etc. Finally, I / O device 507 may also include devices for transmitting both input and output, such as, but not limited to, a NIC or modulator / demodulator (for accessing remote devices, other files, devices, systems, or networks), radio frequency (RF) or other transceivers, telephone interfaces, bridges, routers, etc. I / O device 507 also includes components for communication over various networks such as the Internet or intranets.

[0123] If the computer 500 is a PC, workstation, intelligent device, etc., the software in memory 502 may also include a Basic Input / Output System (BIOS) (omitted for simplicity). The BIOS is a set of essential software routines used to initialize and test the hardware at startup, start O / S 505, and support data transfer between hardware devices. The BIOS is stored in some type of read-only memory, such as ROM, PROM, EPROM, EEPROM, etc., so that the BIOS can be executed when the computer 500 starts.

[0124] When the computer 500 is in operation, the processor 501 is configured to run software stored in the memory 502 to transfer data to and from the memory 502, and typically controls the operation of the computer 500 based on the software. The application program 506 and the operating system 505 are read, possibly cached, and then executed by the processor 501.

[0125] When application 506 is implemented as software, it should be noted that application 506 can be stored on virtually any computer-readable medium for use by or in connection with any computer-related system or method. In the context of this document, a computer-readable medium can be an electronic, magnetic, optical, or other physical device or apparatus that can contain or store computer programs for use by or in connection with a computer-related system or method.

[0126] Application 506 can be implemented on any computer-readable medium for use by or in conjunction with an instruction execution system, apparatus, or device, such as a computer-based system, a processor-containing system, or other system capable of retrieving and executing instructions from and from the instruction execution system, apparatus, or device. In the context of this document, "computer-readable medium" can be any means capable of storing, transmitting, propagating, or transmitting a program for use by or in conjunction with an instruction execution system, apparatus, or device. Computer-readable media can be, for example, but not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, devices, or propagation media.

[0127] It should be understood that the disclosed methods are preferably computer-implemented methods. Thus, the concept of a computer program is also introduced, which includes code units for implementing any described method when the program is run on a processing system (e.g., a computer). Therefore, different portions, lines, or blocks of code of a computer program according to embodiments can be executed by a processing system or computer to perform any of the methods described herein.

[0128] A non-transient storage medium is also proposed for storing or carrying computer programs or computer code that, when executed by a processing system, cause the processing system to perform any of the methods described herein.

[0129] In some alternative embodiments, the order in which functions are recorded in one or more block diagrams or flowcharts may differ from the order recorded in the figures. For example, depending on the functions involved, two blocks shown successively may actually be executed substantially simultaneously, or blocks may sometimes be executed in reverse order.

[0130] Those skilled in the art, through studying the accompanying drawings, the disclosure, and the claims, will be able to understand and implement variations of the disclosed embodiments when practicing the claimed invention. Although specific measures are recited in dissimilar dependent claims, this does not imply that combinations of these measures cannot be advantageously used.

[0131] In the claims, the word "comprising" does not exclude other elements or steps, and the words "a" or "an" do not exclude a plurality. If the term "suitable" is used in the claims or description, it should be noted that the term "suitable" is intended to be equivalent to the term "configured as." If the term "arranged" is used in the claims or description, it should be noted that the word "arranged" is intended to be equivalent to the term "system," and vice versa.

[0132] A single processor or other unit may perform the functions of several claims. If a computer program is described above, it may be stored / distributed on a suitable medium, such as an optical storage medium or a solid-state medium, provided together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems.

[0133] No reference numerals in the claims should be construed as limiting the scope.

Claims

1. A computer-implemented method (200) for outputting one or more indicators of movement of a region of interest within a sequence of ultrasound images (150) of an object (199), the computer-implemented method comprising: The sequence of ultrasound images of the (210) object is obtained; For each ultrasound image in the sequence, the ultrasound image is processed (220) to identify the location of the region of interest (ROI) within the ultrasound image; For each ultrasound image in the sequence, a ROI characterization process (230) is performed, the ROI characterization process including determining (232) the relative position of the identified location of the region of interest with respect to a reference location; In response to the determined relative position for each ultrasound image, one or more indicators are output (240), the one or more indicators comprising a point cloud (310), each point representing an identified position for a corresponding ultrasound image in the sequence of ultrasound images; and Control the user interface to provide a user-aware representation of the one or more indicators.

2. The computer-implemented method according to claim 1, wherein, The output (240) one or more indicators also include defining the properties of each point in the point cloud (310) in response to the position of the corresponding ultrasound image in the sequence of ultrasound images.

3. The computer-implemented method according to claim 2, wherein, The attributes include at least one of the following: opacity, color, intensity, size, shape, and pattern.

4. The computer-implemented method according to claim 1, wherein, For each ultrasound image, the reference location is: the average location of the region of interest across the sequence of ultrasound images; and the centroid of the ultrasound image. Alternatively, it may be located at a predetermined offset from the centroid of the ultrasound image.

5. The computer-implemented method according to claims 1 to 4, wherein: For each ultrasound image, the reference location is the average location of the region of interest across the sequence of ultrasound images; and The computer-implemented method further includes processing the identified location of the region of interest within each ultrasound image to determine the average location of the region of interest across the sequence of ultrasound images.

6. The computer-implemented method according to any one of claims 1 to 5, wherein, The reference position is the mode mean position of the sequence of ultrasound images across the region of interest.

7. The computer-implemented method according to any one of claims 1 to 6, wherein, The ROI characterization process includes determining the distance and orientation between the reference location and the identified location of the region of interest; and The step of outputting one or more indicators includes outputting the point cloud in response to the determined distance and direction.

8. The computer-implemented method according to claim 7, wherein, The ROI characterization process includes: determining the average distance and average orientation between the reference location and the identified location of the region of interest across the sequence of ultrasound images by processing the determined distance and orientation for each ultrasound image in the sequence, and The step of outputting one or more indicators includes outputting indicators in response to the determined average distance and direction.

9. The computer-implemented method according to claim 8, wherein, The step of outputting one or more indicators includes outputting a line representing the determined average distance and average direction.

10. The computer-implemented method according to any one of claims 1 to 9, wherein, The ROI characterization process includes determining the relative position of the identified location of the region of interest with respect to the reference location in polar coordinates.

11. The computer-implemented method according to claim 10, wherein: The ROI characterization process includes determining the distance and orientation between the reference location and the identified location of the region of interest; and In the ROI characterization process, the step of determining the relative position of the identified location of the region of interest with respect to the reference location in the polar coordinate system includes: processing the determined distance and direction to generate polar coordinates of the identified location in the polar coordinate system.

12. The computer-implemented method according to claim 10, wherein, The identified location of the region of interest and the reference location are defined using Cartesian coordinates in a Cartesian coordinate system. and In the ROI characterization process, the step of determining the relative position of the identified location of the region of interest with respect to the reference location in the polar coordinate system includes: for each dimension of the Cartesian coordinate system: A quotient is generated by dividing the value of the identified location by the value of the reference location; and The quotient is multiplied by the maximum possible value of the dimension relative to the Cartesian coordinate system of the ultrasound image.

13. A computer program product comprising computer program code, said computer program code, when run on a computing device having a processing system, causing said processing system to perform all the steps of the method according to any one of claims 1 to 12.

14. A processing system for outputting one or more indicators of movement of a region of interest within a sequence of ultrasound images of an object, the processing system being configured to perform the method according to any one of claims 1 to 12.

15. An ultrasound imaging system, comprising: The processing system according to claim 14; as well as An ultrasonic transducer configured to generate the sequence of ultrasonic images of the object.

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