Systems and methods for quantitative assessment of microvasculature using optical coherence tomography angiography

1. A method of analyzing an anatomical region of interest of a subject, the method comprising:

acquiring vascular image data from the region of interest of the subject;

generating a binary vasculature map from the vascular image data;

generating a vessel skeleton map from the binary vasculature map;

identifying a flow impairment zone in the region of interest based on the vessel skeleton map;

generating a vessel perimeter map from the binary vasculature map; and

based on the binarized vasculature map, the vessel skeleton map, and the vessel perimeter map, determining each of—

a vasculature density index;

a vessel diameter index; and

a vessel complexity index.

2. The method of claim 1 wherein determining a vasculature density index comprises determining each of a vessel area density, a vessel skeleton density, and a vessel perimeter index, and wherein:

the vessel area density is determined based on the binary vasculature map;

the vessel skeleton density is determined based on the vessel skeleton map;

the vessel perimeter index is determined based on the vessel perimeter map;

the vessel diameter index is determined based on both the binary vasculature map and the vessel skeleton map; and

the vessel complexity index is determined based on both the binary vasculature map and the vessel perimeter map.

3. The method of claim 1 , further comprising, based on at least one of the determined vasculature density index, vessel diameter index, vessel complexity index, or flow impairment zone, evaluating treatment efficacy monitoring treatment of at least one of a branch retinal vein occlusion, central retinal vein occlusion, glaucoma, age-related macular degeneration, diabetic retinopathy, or macular telangiectasia type 2.

4. The method of claim 1 , further comprising, based on at least one of the determined vasculature density index, vessel diameter index, vessel complexity index, or flow impairment zone, detecting the presence of a vascular abnormality.

5. The method of claim 1 wherein the vasculature density index comprises a vessel area density, and wherein the vessel area density is determined based, at least in part, on the relationship of vessel pixels in the binary vasculature map and total pixels in the binary vasculature map.

6. The method of claim 1 wherein the vasculature density index comprises a vessel skeleton density, and wherein the vessel skeleton density is determined based, at least in part, on a relationship between vessel skeleton pixels in the vessel skeleton map and total pixels in the vessel skeleton map.

7. The method of claim 1 wherein the vasculature density index comprises a vessel perimeter index, and wherein the vessel perimeter index is determined based, at least in part, on a relationship between vessel perimeter pixels in the vessel perimeter map and total pixels in the vessel perimeter map.

8. The method of claim 1 wherein the vessel diameter index is determined based, at least in part, on a relationship between vessel perimeter pixels in the vessel perimeter map and vessel skeleton pixels in the vessel skeleton map.

9. The method of claim 1 wherein the vessel complexity index is determined based, at least in part, on a relationship between vessel perimeter pixels in the vessel perimeter map and vessel pixels in the binary vasculature map.

10. A method of operating a medical imaging system to evaluate a region of interest of a subject, the method comprising:

transmitting a plurality of light pulses from a laser light source toward the region of interest of the subject;

receiving backscattered light from the region of interest at a detector optically coupled to the laser light source;

acquiring data from the region of interest using signals generated by the detector that are indicative of backscattered light received at the detector;

based on the acquired data, generating a binary vessel map;

based on the binarized vessel map, generating a vessel skeleton map and a vessel perimeter map;

based on the binary vessel map, the vessel skeleton map, and the vessel perimeter map, determining each of—

a vasculature density index;

a vessel diameter index; and

a vessel complexity index.

11. The method of claim 10 , wherein determining a vasculature density index comprises determining each of: a vessel area density, a vessel skeleton density, and a vessel perimeter density, and wherein:

the vessel area density is determined based on the binary vasculature map;

the vessel skeleton density is determined based on the vessel skeleton map;

the perimeter vessel density is determined based on the vessel perimeter map;

the vessel diameter index is determined based on both the binary vasculature map and the vessel skeleton map; and

the vessel complexity index is determined based on both the binary vasculature map and the vessel perimeter map.

12. The method of claim 10 , further comprising identifying a flow impairment zone in the region of interest based on the vessel skeleton map.

13. The method of claim 10 wherein the vasculature density index comprises a vessel perimeter index, and wherein the vessel perimeter index is determined based on a relationship between vessel perimeter pixels in the vessel perimeter map and total pixels in the vessel perimeter map.

14. The method of claim 10 wherein the vessel diameter index is determined based on a relationship between vessel perimeter pixels in the vessel perimeter map and vessel skeleton pixels in the vessel skeleton map.

15. The method of claim 1 , wherein the vessel complexity index is determined based on a relationship between vessel perimeter pixels in the vessel perimeter map and vessel pixels in the binary vasculature map.

16. A medical imaging system configured to produce and analyze images of a subject, the system comprising:

a light source configured to produce laser light;

an imaging module optically coupled to the light source, wherein the imaging module is configured to (a) direct the laser light toward a region of interest in the subject and (b) receive backscattered light from the subject;

a detector optically coupled to the imaging module, wherein the detector is configured to produce electrical signals that correspond to light received from the imaging module; and

a processor and memory operatively coupled to the detector, wherein the memory includes instructions that, when executed by the processor, are configured to perform the operations including—

acquiring image data from the region of interest in the subject using the signals produced by the detector;

constructing a binary vasculature map based on the acquired image data;

constructing a vessel skeleton map and a vessel perimeter map based on the binary vasculature map;

based on the binary vessel map, the vessel skeleton map, and the vessel perimeter map, determining each of—

a vasculature density index;

a vessel diameter index; and

a vessel complexity index.

17. The system of claim 16 wherein the memory further includes instructions that, when executed by the processor, are configured to perform the operations such that determining a vasculature density index comprises determining each of: a vessel area density, a vessel skeleton density, and a vessel perimeter density, and wherein:

the vessel area density is determined based on the binary vasculature map;

the vessel skeleton density is determined based on the vessel skeleton map;

the perimeter vessel density is determined based on the vessel perimeter map;

the vessel diameter index is determined based on both the binary vasculature map and the vessel skeleton map; and

the vessel complexity index is determined based on both the binary vasculature map and the vessel perimeter map.

18. The system of claim 16 wherein the memory further includes instructions that, when executed by the processor, are configured to perform the operation of identifying a flow impairment zone in the region of interest based on the vessel skeleton map.

19. The system of claim 16 wherein the memory further includes instructions that, when executed by the processor, are configured to perform the operation of indicating detection of a physiological abnormality based on one or more of the determined vasculature density index, vessel diameter index, the vessel complexity index, or flow impairment zone.