Systems and methods for high dynamic range optical coherence tomography angiography (HDR-OCTA)

Patent metadata

Field	Value
Publication number	US-11937878-B2
Application number	US-202017098152-A
Country	US
Kind code	B2
Filing date	Nov 13, 2020
Priority date	Nov 18, 2019
Publication date	Mar 26, 2024
Grant date	Mar 26, 2024

Abstract

Disclosed herein are methods and systems for optical coherence tomography (OCT) angiography (OCTA). An interleaved scanning pattern is described herein for both raster and bidirectional scanning methods. The interleaved scanning pattern provides B-scans with different scanning intervals. OCTA images based on the B-scans may be combined to obtain a high dynamic range (HDR) OCTA image. Other embodiments may be described and claimed.

First claim

The invention claimed is:

1. A method for optical coherence tomography angiography (OCTA) imaging, comprising:
obtaining three or more optical coherence tomography (OCT) B-scans at each of a plurality of cross-sectional positions along a slow axis using a stepped scanning pattern on the slow axis, wherein the obtaining the OCT B-scans includes:
obtaining a first OCT B-scan, a second OCT B-scan, and a third OCT B-scan at a first cross-sectional position of the cross-sectional positions, wherein a first time period between the first and second OCT B-scans is different than a second time period between the second and third OCT B-scans, and wherein a third time period between the first and third OCT B-scans is different than the first and second time periods; and
obtaining, via the stepped scanning pattern on the slow axis, at least one of the OCT B-scans at one or more other cross-sectional positions of the plurality of cross-sectional positions in between the first and second OCT B-scans or second and third OCT B-scans at the first cross-sectional position;

generating multiple OCTA images based on the three or more OCT B-scans at each of the plurality of cross-sectional positions; and
combining the multiple OCTA images to obtain a high dynamic range (HDR) OCTA image.

2. The method of claim 1 , wherein the obtaining the OCT B-scans includes:
obtaining the first OCT B-scan at the first cross-sectional position;
obtaining a first number of the OCT B-scans at the one or more other cross-sectional positions after obtaining the first OCT B-scan;
obtaining the second OCT B-scan at the first cross-sectional position after obtaining the first number of OCT B-scans;
obtaining a second number of OCT B-scans at one or more additional cross-sectional positions, of the plurality of cross-sectional positions, after obtaining the second OCT B-scan, wherein the second number is different than the first number; and
obtaining the third OCT B-scan at the first cross-sectional position after obtaining the second number of OCT B-scans.

3. The method of claim 2 , wherein the first number of OCT B-scans is one, and wherein the second number of OCT B-scans is greater than one.

4. The method of claim 3 , wherein the second number of OCT B-scans is 3.

5. The method of claim 2 , wherein the OCT B-scans are obtained using bidirectional scanning.

6. The method of claim 1 , wherein the obtaining the OCT B-scans includes:
obtaining the first OCT B-scan at the first cross-sectional position;
obtaining the second OCT B-scan at the first cross-sectional position after obtaining the first OCT B-scan;
obtaining the one or more OCT B-scans at the one or more other cross-sectional positions after obtaining the first and second OCT B-scans; and
obtaining the third OCT B-scan at the first cross-sectional position after obtaining the one or more OCT B-scans at the one or more other cross-sectional positions.

7. The method of claim 6 , wherein the first and second OCT B-scans are obtained sequentially.

8. The method of claim 7 , further comprising performing a flyback of a scanner between obtaining the first and second OCT B-scans.

9. The method of claim 6 , wherein the obtaining one or more OCT B-scans at the one or more other cross-sectional positions comprises obtaining one OCT B-scan at a second cross-sectional position that is adjacent to the first cross-sectional position along the slow axis.

10. The method of claim 6 , wherein the OCT B-scans are obtained using raster scanning.

11. The method of claim 6 , wherein the one or more OCT B-scans at the one or more other cross-sectional positions are a first number of OCT B-scans, and wherein the method further comprises obtaining a second number of the OCT B-scans at one or more additional cross-sectional positions, of the plurality of cross-sectional positions, between obtaining the first OCT B-scan and obtaining the second OCT B-scan.

12. The method of claim 1 , wherein the OCT B-scans are obtained via bi-directional scanning, wherein the at least one of the OCT B-scans at one or more other cross-sectional positions includes a first OCT B-scan and a second OCT B-scan at a second cross-sectional position, and wherein the obtaining the OCT B-scans includes:
sequentially obtaining the first OCT B-scan at the first cross-sectional position and the first OCT B-scan at the second cross-sectional position;
sequentially obtaining, after obtaining the first OCT B-scans at the first and second cross-sectional positions, the second OCT B-scan at the first cross-sectional position and the second OCT B-scan at the second cross-sectional position;
sequentially obtaining first OCT B-scans at two or more additional cross-sectional positions after obtaining the first and second OCT B-scans at the first and second cross-sectional positions; and
sequentially obtaining, after obtaining the first OCT B-scans at the two or more additional cross-sectional positions, the third OCT B-scan at the first cross-sectional position and a third OCT B-scan at the second cross-sectional position.

13. The method of claim 1 , wherein the multiple OCTA images are generated based on respective pairs of the OCT B-scans at the same cross-sectional position.

14. A system for optical coherence tomography angiography (OCTA), the system comprising:
an optical coherence tomography (OCT) system;
a logic subsystem; and
a data holding subsystem comprising non-transitory machine-readable instructions stored thereon that are executable by the logic subsystem to:
obtain, via the OCT system, three or more OCT B-scans of a sample at each of a plurality of cross-sectional positions along a slow axis using a stepped scanning pattern on the slow axis, wherein to obtain the OCT B-scans includes to:
obtain a first OCT B-scan, a second OCT B-scan, and a third OCT B-scan at a first cross-sectional position of the cross-sectional positions, wherein a first time period between the first and second OCT B-scans is different than a second time period between the second and third OCT B-scans, and wherein a third time period between the first and third OCT B-scans is different than the first and second time periods; and
obtain, via the stepped scanning pattern on the slow axis, at least one of the OCT B-scans at one or more other cross-sectional positions of the plurality of cross-sectional positions in between the first and second OCT B-scans or second and third OCT B-scans at the first cross-sectional position;
generate multiple OCTA images based on the three or more OCT B-scans at each of the plurality of cross-sectional positions; and
combine the multiple OCTA images to obtain a high dynamic range (HDR) OCTA image.

15. The system of claim 14 , wherein to obtain the OCT B-scans includes to:
obtain the first OCT B-scan at the first cross-sectional position;
obtain a first number of the OCT B-scans at the one or more other cross-sectional positions after the first OCT B-scan is obtained;
obtain the second OCT B-scan at the first cross-sectional position after the first number of OCT B-scans is obtained;
obtain a second number of OCT B-scans at one or more additional cross-sectional positions, of the plurality of cross-sectional positions, after the second OCT B-scan is obtained, wherein the second number is different than the first number; and
obtain the third OCT B-scan at the first cross-sectional position after the second number of OCT B-scans is obtained.

16. The system of claim 15 , wherein the first number of OCT B-scans is one, and wherein the second number of OCT B-scans is greater than one.

Assignees

• Univ Oregon Health & Science

Inventors

• Wei Xiang
• Jia Yali

Classifications

• A61B3/1233 Primary

  for measuring blood flow, e.g. at the retina · CPC title

• A61B3/102 Primary

  for optical coherence tomography [OCT] · CPC title

• G06T5/009

  Physics · mapped topic

• G06T5/50

  using two or more images, e.g. averaging or subtraction · CPC title

• G06T2207/10101

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