Method and apparatus for adaptive cross-sectional area computation of IVUS objects using their statistical signatures

A method for evaluating an object within the ultrasound image, the method comprising:

• obtaining in-vivo ultrasound image data in a plurality of frames;
• constructing images from each frame of data, wherein the images include at least one object;
• identifying the object within each image by moving a region of interest to different locations in the image and evaluating object identifying parameters at the different locations to determine if the parameters fall within an acceptable range of object identifying parameters indicative of the object;
• computing the area of the object within each of the frames based on the locations having the parameters which fall within the acceptable range;
• comparing the areas of two adjacent frames;
• and
• recomputing the area of one of the adjacent frames using different criteria if the difference between the two areas exceeds a predetermined amount.

A method for evaluating an object within an ultrasound image constructed from time-domain data, the method comprising:

• a) selecting a region of interest within the object for observation;
• b) at the selected region of interest, computing a transform of time-domain data that is representative of reflections from said region of interest to obtain frequency-domain data;
• c) compressing the frequency-domain data;
• d) obtaining object identifying parameters from the compressed frequency-domain data;
• e) defining multiple definition regions of interest which are subsets of the selected region of interest, wherein each definition region of interest is located at a distinct location within the selected region of interest;
• f) computing a transform of the time-domain data defining the definition regions of interest to obtain frequency-domain data representative of the definition regions of interest;
• g) determining a range of acceptable object identifying parameters from the frequency-domain data which is representative of the definition regions of interest;
• h) at selected definition regions of interest in the ultrasound image, computing transforms of the time-domain data to obtain frequency-domain data representative of the definition regions of interest in the ultrasound image;
• i) obtaining object identifying parameters from the frequency-domain data representative of the definition regions of interest in the ultrasound image;
• j) determining if the object identifying parameters from the frequency-domain data representative of the definition regions of interest in the ultrasound image are within the range of acceptable object identifying parameters;
• k) flagging the selected definition regions of interest in the ultrasound image which have object identifying parameters which fall within the acceptable range;
• and
• l) constructing an object boundary around the flagged selected definition regions of interest.

An ultrasound imaging system comprising:

• a processor;
• a memory to store in-vivo ultrasound image data;
• a display screen coupled to the processor;
• code to display an image from the data on the display screen, wherein the image includes at least one object;
• code to calculate with the processor at least two parameters from the data for selected locations within the object, wherein the parameters are representative of the intensity of the object in the image and the spacial structure of the object in the image;
• and
• code to construct an object boundary along a region of interest.

An ultrasound imaging system comprising:

• a processor;
• a memory to store in-vivo ultrasound image data in a plurality of frames;
• a display screen coupled to the processor;
• code to display images from each frame of data on the display screen, wherein the images include at least one object;
• code to identify the object within each image by moving a region of interest to different locations in the image and evaluating object identifying parameters at the different locations to determine if the parameters fall within an acceptable range of object identifying parameters indicative of the object;
• code to compute the area of the object within each of the frames based on the locations having the parameters which fall within the acceptable range;
• code to compare the areas of two adjacent frames;
• code to recompute the area of one of the adjacent frames using different criteria if the difference between the two areas exceeds a predetermined amount;
• and
• code to construct an object boundary along a region of interest.