Feature tracking using ultrasound

Abstract

Various implementations of the invention provide techniques and supporting systems that facilitate real-time or near-real-time ultrasound tracking for the purpose of calculating changes in anatomical features during a medical procedure. More specifically, anatomical features within a patient undergoing a medical procedure are tracked by obtaining temporally-distinct three dimensional ultrasound images that include the feature of interest and obtaining a targeted subset of ultrasound images focused on the feature. Based on the targeted subset of ultrasound images, a displacement of the feature is determined and image parameters used to obtain the targeted subset of ultrasound images are adjusted based on the displacement. This results in a time-based sequence of three dimensional images and targeted ultrasound images of the feature that identify changes in the position, size, location, and/or shape of the feature.

1 . A method of using a processor circuit executing a plurality of computer-executable instructions for monitoring one or more anatomical features of a patient, comprising:
 controlling an ultrasound imaging probe to acquire first three-dimensional image data including a first three-dimensional image of a volume of interest including an anatomical feature;   reducing a size of the volume of interest from a first size to a second size to encompass only the anatomical feature plus a specified amount of surrounding voxels;   reconstructing a second three-dimensional image of the reduced size volume of interest having the second size;   determining whether the anatomical feature is present in the second three-dimensional image;   in response to determining that the anatomical feature is not present in the second three-dimensional image or is close to a boundary in the second three-dimensional image, controlling the ultrasound imaging probe to acquire second three-dimensional image data including a third three-dimensional image of the volume of interest having the first size; and   in response to determining that the anatomical feature is present in the second three-dimensional image, modifying a radiotherapy treatment plan to compensate for a location of the anatomical feature.   
     
     
         2 . The method of  claim 1 , wherein reducing the size of the volume of interest comprises limiting a sector size of two-dimensional ultrasound frames through an ultrasound sweep. 
     
     
         3 . The method of  claim 2 , wherein the sector size is limited asymmetrically or based on a depth of penetration. 
     
     
         4 . The method of  claim 1 , wherein reducing the size of the volume of interest increases a frame-rate and sweeping motion speed while maintaining a sufficient number of slices for reconstructing the three-dimensional image. 
     
     
         5 . The method of  claim 1 , wherein the second three-dimensional image data is acquired at specified time intervals. 
     
     
         6 . A system for controlling an ultrasound imaging probe to monitor an anatomical feature of a patient, comprising:
 a memory circuit for storing instructions and image data; and   a processor circuit for executing the instructions to perform operations comprising:
 controlling an ultrasound imaging probe to acquire first three-dimensional image data including a first three-dimensional image of a volume of interest including an anatomical feature; 
 reducing a size of the volume of interest from a first size to a second size to encompass only the anatomical feature plus a specified amount of surrounding voxels; 
 reconstructing a second three-dimensional image of the reduced size volume of interest having the second size; 
 determining whether the anatomical feature is present in the second three-dimensional image; 
 in response to determining that the anatomical feature is not present in the second three-dimensional image or is close to a boundary in the second three-dimensional image, controlling the ultrasound imaging probe to acquire second three-dimensional image data including a third three-dimensional image of the volume of interest having the first size; and 
 in response to determining that the anatomical feature is present in the second three-dimensional image, modifying a radiotherapy treatment plan to compensate for a location of the anatomical feature. 
   
     
     
         7 . The system of  claim 6 , wherein reducing the size of the volume of interest comprises limiting a sector size of two-dimensional ultrasound frames through an ultrasound sweep. 
     
     
         8 . The system of  claim 7 , wherein the sector size is limited asymmetrically or based on a depth of penetration. 
     
     
         9 . The system of  claim 6 , wherein reducing the size of the volume of interest increases a frame-rate and sweeping motion speed while maintaining a sufficient number of slices for reconstructing the three-dimensional image. 
     
     
         10 . The system of  claim 6 , wherein the second three-dimensional image data is acquired at specified time intervals. 
     
     
         11 . A method of using a processor circuit executing a plurality of computer-executable instructions for monitoring one or more anatomical features of a patient, comprising:
 controlling an ultrasound imaging probe to acquire first three-dimensional image data including a first three-dimensional image of a volume of interest including an anatomical feature;   reconstructing image data in two or more tracking planes based on the first three-dimensional image of the volume of interest;   locating a three-dimensional feature, corresponding to the anatomical feature, within the reconstructed image data in the two or more tracking planes;   determining whether the three-dimensional feature intersects at least one of the two or more tracking planes to determine displacement of the three-dimensional feature relative to a previous point in time;   in response to determining that the three-dimensional feature fails to intersect at least one of the two or more tracking planes, controlling the ultrasound imaging probe to acquire second three-dimensional image data including a second three-dimensional image of the volume of interest; and   in response to determining that the three-dimensional feature intersects at least one of the two or more tracking planes, modifying a radiotherapy treatment plan to compensate for a location of the three-dimensional feature.   
     
     
         12 . The method of  claim 11 , wherein the two or more tracking planes are orthogonal to each other. 
     
     
         13 . The method of  claim 11 , further comprising controlling the ultrasound imaging probe to acquire a two-dimensional image along a third tracking plane position that intersects a region of the three-dimensional feature. 
     
     
         14 . The method of  claim 11 , further comprising obtaining pixels from multiple two-dimensional images obtained from different plane positions of the ultrasound imaging probe instead of reconstructing the image data based on the first three-dimensional image. 
     
     
         15 . The method of  claim 14 , wherein the different plane positions include three plane positions, a first of the three plane positions selected to pass through a center of the three-dimensional feature, a second of the three plane positions selected to pass through a first side left of the center of the three-dimensional feature, and a third of the three plane positions selected to pass through a second side right of the center of the three-dimensional feature. 
     
     
         16 . The method of  claim 11 , further comprising producing a two-dimensional curve based on an intersection of first and second planes of the two or more tracking planes and the three-dimensional feature. 
     
     
         17 . The method of  claim 11 , wherein locating the three-dimensional feature comprises determining that the three-dimensional feature is visible in the two or more tracking planes. 
     
     
         18 . The method of  claim 11 , further comprising re-centering a position of the two or more tracking planes based on determining displacement of the three-dimensional feature relative to a previous point in time. 
     
     
         19 . A system for controlling an ultrasound imaging probe to monitor an anatomical feature of a patient, comprising:
 a memory circuit for storing instructions and image data; and   a processor circuit for executing the instructions to perform operations comprising:
 controlling an ultrasound imaging probe to acquire first three-dimensional image data including a first three-dimensional image of a volume of interest including an anatomical feature; 
 reconstructing image data in two or more tracking planes based on the first three-dimensional image of the volume of interest; 
 locating a three-dimensional feature, corresponding to the anatomical feature, within the reconstructed image data in the two or more tracking planes; 
 determining whether the three-dimensional feature intersects at least one of the two or more tracking planes to determine displacement of the three-dimensional feature relative to a previous point in time; 
 in response to determining that the three-dimensional feature fails to intersect at least one of the two or more tracking planes, controlling the ultrasound imaging probe to acquire second three-dimensional image data including a second three-dimensional image of the volume of interest; and 
 in response to determining that the three-dimensional feature intersects at least one of the two or more tracking planes, modifying a radiotherapy treatment plan to compensate for a location of the three-dimensional feature. 
   
     
     
         20 . The system of  claim 19 , wherein the two or more tracking planes are orthogonal to each other. 
     
     
         21 . The system of  claim 19 , further comprising controlling the ultrasound imaging probe to acquire a two-dimensional image along a third tracking plane position that intersects a region of the three-dimensional feature. 
     
     
         22 . The system of  claim 19 , further comprising obtaining pixels from multiple two-dimensional images obtained from different plane positions of the ultrasound imaging probe instead of reconstructing the image data based on the first three-dimensional image. 
     
     
         23 . The system of  claim 22 , wherein the different plane positions include three plane positions, a first of the three plane positions selected to pass through a center of the three-dimensional feature, a second of the three plane positions selected to pass through a first side left of the center of the three-dimensional feature, and a third of the three plane positions selected to pass through a second side right of the center of the three-dimensional feature.