Removal of A-scan streaking artifact

Patent metadata

Field	Value
Publication number	US-9324141-B2
Application number	US-201314044476-A
Country	US
Kind code	B2
Filing date	Oct 2, 2013
Priority date	Oct 5, 2012
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

This invention generally relates to the removal of streaking artifacts and periodic noise from tomographic images. The method comprises obtaining an A-scan from an imaging data set. The A-scan having a signal and the signal defining an amplitude. Noise specific to the A-scan is estimated. The amplitude of the A-scan is scaled based on its specific estimated noise floor. In another aspect, a plurality of A-scans is obtained from an imaging data set. Each of the plurality of A-scans has a signal and the signal defines an amplitude. Noise specific to each A-scan of the plurality of A-scans is estimated. Each A-scan of the plurality of A-scans is scaled by the A-scan's specific estimated noise floor.

First claim

What is claimed is:

1. A nontransitory computer-readable medium storing software code representing instructions that when executed by a computing system cause the computing system to perform a method of reducing noise in a tomographic image, the method comprising
obtaining an A-scan from an imaging data set, the A-scan having a signal and the signal defining an amplitude;
estimating a noise floor specific to the A-scan by performing a moving average across the A-scan to obtain a miminum average wherein the mininmum average comprises the estimated noise floor;
scaling the amplitude of the signal based on the estimated noise floor;
combining the scaled A-scans to form a B-scan; and
scan-converting the B-scan into a Cartesian coordinate system to create a final tomographic view of the image with reduced noise.

2. The computer-readable medium of claim 1 , wherein the step of scaling comprises reducing the amplitude of the signal based on the estimated noise floor.

3. The computer-readable medium of claim 1 , wherein the moving average comprises computing the arithmetic mean, geometric mean, harmonic mean or quadratic mean within a sliding window across the A-scan.

4. The computer-readable medium of claim 1 , wherein the step of scaling further comprises adding a constant noise floor to the amplitude of the signal.

5. A nontransitory computer-readable medium storing software code representing instructions that when executed by a computing system cause the computing system to perform a method of reducing noise in a tomographic image, the method comprising
obtaining a plurality of A-scans from an imaging data set, each of the plurality of A-scans having a signal and the signal defining an amplitude;
estimating a noise floor specific to each of the plurality of A-scans;
scaling the amplitude of the signal in each of the plurality of A-scans based on the estimated specific noise floor for the corresponding A-scan;
combining the scaled A-scans to form a B-scan; and
scan-converting the B-scan into a Cartesian coordinate system to create a final tomographic view of the image with reduced noise.

6. The computer-readable system of claim 5 , wherein the step of estimating comprises
averaging the amplitude of the signal at a plurality of pixels within a window of the A-scan.

7. The computer-readable medium of claim 5 , wherein the step of estimating comprises
performing a moving average across the A-scan.

8. The computer-readable medium of claim 7 , wherein the minimum average obtained from the performed moving average comprises the estimated noise floor.

9. The computer-readable medium of claim 5 , wherein scaling comprises reducing the amplitude of the signal based on the estimated specific noise floor.

10. The computer-readable of claim 6 , wherein the step of averaging comprises computing the arithmetic mean, geometric mean, harmonic mean or quadratic mean.

11. The computer-readable of claim 7 , wherein the moving average comprises computing the arithmetic mean, geometric mean, harmonic mean or quadratic mean within a sliding window across the A-scan.

12. The computer-readable medium of claim 5 , wherein the step of scaling further comprises adding a constant noise floor to the amplitude of the signal.

13. A system for imaging and reducing noise within a tomographic image, comprising:
a central processing unit (CPU); and
a storage device coupled to the CPU and having stored there information for configuring the CPU to:
obtain an A-scan from an imaging data set, the A-scan having a signal and the signal defining an amplitude;
estimate a noise floor specific to the A-scan by computing an arithmetic mean, geometric mean, harmonic mean or quadratic mean within a sliding window across the A-scan;
scale the amplitude of the signal based on the estimated noise;
combining the scaled A-scans to form a B-scan; and
scan-converting the B-scan into a Cartesian coordinate system to create a final tomographic view of the image with reduced noise.

14. The system of claim 13 , wherein the minimum average obtained from the performed moving average comprises the estimated noise floor.

15. The system of claim 13 , wherein scaling comprises reducing the amplitude of the signal based on the estimated noise floor.

16. The system of claim 13 , wherein scaling further comprises adding a constant noise floor to the amplitude of the signal.

Assignees

• Volcano Corp

Inventors

• Begin Elizabeth

Classifications

• G06T2207/30101

  Blood vessel; Artery; Vein; Vascular · CPC title

• G06T2207/10101

  Optical tomography; Optical coherence tomography [OCT] · CPC title

• G06T2207/20012

  Locally adaptive · CPC title

• G06T7/0012 Primary

  Biomedical image inspection · CPC title

• G06T5/002

  Physics · mapped topic