Systems and methods for evaluating objects within an ultrasound image

• US 6,287,259 B1
• Filed: 02/17/2000
• Issued: 09/11/2001
• Est. Priority Date: 10/02/1998
• Status: Expired due to Term

• Current Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Grunwald, Sorin
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): PATEL, MAULIN M
• Application Number:
  US09/506,513
• Time in Patent Office: 572 Days
• Field of Search: 600/437, 600/438, 600/443, 600/447, 600/449, 600/466, 600/467
• US Class Current: 600/437
• CPC Class Codes: A61B 8/00 Diagnosis using ultrasonic, sonic or infrasonic waves imaging of objects using sonar G01S15/00
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: G01S 7/52036 using analysis of echo signal for target characterisation

Abstract

According to the invention, an object in an ultrasound image is characterized by considering various in-vivo object parameters and their variability within the ultrasonic imaging data. Specifically, it is assumed that the object may be defined in terms of statistical properties (or object identifying parameters), which are consistently different from properties of the environment. Such properties are referred to as the object'"'"'s signature. The statistical properties are calculated at selected locations within the image to determine if they fall within a predetermined range of values which represents the object. If within the range, the locations are marked to indicate they are positioned within the object. A border may then be drawn around the object and the area calculated.

Claims

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

obtaining in-vivo ultrasound image data indicative of an object and the environment surrounding the object;

constructing an image from the data, wherein the image includes a depiction of the object and the surrounding environment;

calculating statistical properties from the data at locations within the image;

determining whether the statistical properties are within a certain range that is representative of the object; and

constructing a border around the object depicted in the image based at least in part on the determination.

2. A method as in claim 1, wherein the data is time-domain data, further comprising transforming the time-domain data into frequency-domain data and compressing the frequency-domain data, and wherein the statistical properties include parameters that comprise the zero frequency magnitude of the compressed frequency-domain data and the sum of the frequency magnitudes of the compressed frequency-domain data.

3. A method as in claim 2, wherein the object is representative of a physical object within a patient, and wherein the zero frequency magnitude of the compressed frequency-domain data is representative of the physical composition of the physical object, and the sum of the frequency magnitudes of the compressed frequency-domain data is representative of the homogeneity of the physical object.

4. A method as in claim 2, further comprising introducing a catheter into a patient an actuating an ultrasonic element to obtain the time-domain data.

5. 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 at least some of the frames 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; and

computing the area of the object within each of the frames based on the locations having the parameters which fall within the acceptable range.

6. A method as in claim 5, further comprising comparing the areas of two adjacent frames, recomputing the area of one of the adjacent frames using different criteria if the difference between the two areas exceeds a predetermined amount, and varying the range of object identifying parameters to recompute the area of one of the adjacent frames.

7. A method as in claim 5, further comprising varying a starting location of the region of interest to recompute the area of one of the adjacent frames.

8. A method as in claim 5, further comprising varying the size of the region of interest to recompute the area of one of the adjacent frames.

9. A method as in claim 6, further comprising producing a message if the difference between recomputed area and the area of the object in the adjacent frame still exceeds the predetermined amount.

10. 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 statistical properties from the data at locations within the image and to determine whether the statistical properties are within a certain range that is representative of the object; and

code to construct an object boundary around the object.

11. A system as in claim 10, wherein the data is time-domain data, further comprising code to transform with the processor the time-domain data into frequency-domain data and to compress the frequency-domain data, and wherein the statistical properties include parameters that comprise the zero frequency magnitude of the compressed frequency-domain data and the sum of the frequency magnitudes of the compressed frequency-domain data.

12. A system as in claim 11, wherein the object is representative of a physical object within a patient, and wherein the zero frequency magnitude of the compressed frequency-domain data is representative of the physical structure of the physical object, and the sum of the frequency magnitudes of the compressed frequency-domain data is representative of the homogeneity of the physical object.

13. A system as in claim 11, further comprising a catheter having an ultrasonic element which is coupled to the processor to obtain the time-domain data when the catheter is inserted into a patient.

14. 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; and

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.