Spectral contrast optical coherence tomography angiography

1. A method for imaging a target comprising steps of:

performing optical coherence tomography (OCT) scanning on the target with one or more beams of source light, the one or more beams of source light comprising a plurality of wavelengths; wherein performing OCT scanning comprises:

providing the source light to a reference optical path and to a sample optical path, wherein providing the source light to a sample optical path comprises illuminating the target with the source light; and

recording interference data corresponding to an interaction of a light from the reference optical path and a light from the sample optical path;

processing the interference data, comprising:

determining at least a first Fourier transform and a second Fourier transform from the interference data; wherein the first Fourier transform corresponds to a first sampling window and the second Fourier transform corresponds to a second sampling window;

determining at least one spectral contrast OCT (SC-OCT) characteristic based on the at least the first Fourier transform and the second Fourier transform, wherein the at least one SC-OCT characteristic is at least one of a spectral contrast OCT (SC-OCT) ratio of the second Fourier transform to the first Fourier transform and a spectral contrast OCT (SC-OCT) difference between the second Fourier transform and the first Fourier transform; and

identifying blood or one or more blood-features in the target based on an optical attenuation of light in or associated with the sample optical path by the blood or the one or more blood-features.

2. The method of claim 1 , wherein the one or more blood features comprises hemoglobin, red blood cells, or any combination thereof; and the method further comprising differentiating the blood or the one or more blood-features from one or more non-blood-features in the target.

3. The method of claim 1 , wherein the first Fourier transform is a first short time Fourier transform (STFT) and the second Fourier transform is a second short time Fourier transform (STFT); wherein the at least one SC-OCT characteristic is at least one of a spectral contrast OCT (SC-OCT) ratio of the second STFT to the first STFT and a spectral contrast OCT (SC-OCT) difference between the second STFT and the first STFT.

4. The method claim 1 , further comprising generating a spectral contrast OCT (SC-OCT) image of the target using the SC-OCT characteristic.

5. The method of claim 4 , further comprising generating a spectral contrast OCT (SC-OCT) image of the target using at least one of the SC-OCT ratio and the SC-OCT difference.

6. The method of claim 1 , further comprising differentiating the blood or the one or more blood-features from the one or more non-blood-features in the target using the SC-OCT image.

7. The method of claim 1 , further comprising determining an inverse of at the least one of the first Fourier transform and the second Fourier transform; and the method further comprising generating an image based on the inverse of the at least one of the first Fourier transform and the second Fourier transform.

8. The method of claim 1 , further comprising performing a depth integration using the SC-OCT characteristic and generating a depth-integrated SC-OCT (DI-SC-OCT) image.

9. The method of claim 8 , further comprising performing a depth integration using the SC-OCT characteristic and generating a depth-integrated SC-OCT (DI-SC-OCT) image; wherein the SC-OCT image comprises a plurality of pixels and wherein performing depth integration comprises integrating data corresponding to each of the plurality of pixels along a depth and multiplying by data corresponding to the inverse of the at least one of the first Fourier transform and the second Fourier transform.

10. The method of claim 1 , further comprising determining an inverse of at the least one of the first Fourier transform and the second Fourier transform, and further comprising acquiring full-spectrum OCT data of the target and generating one or more three-dimensional (3D) images of the target using at least two of the inverse of the at least one of the first Fourier transform and the second Fourier transform, the SC-OCT characteristic, and a full-spectrum OCT data.

11. The method of claim 1 , wherein determining the first Fourier transform comprises determining a first window function and the first Fourier transform corresponds to the first window function; and wherein determining the second Fourier transform comprises determining a second window function and the second Fourier transform corresponds to the second window function; wherein the first window function corresponds to a first wavelength range and the second window function corresponds to a second wavelength range; and wherein the first wavelength range and the second wavelength range are substantially in the visible light range of the electromagnetic spectrum.

12. The method of claim 11 , further comprising differentiating the blood or the one or more blood-features from one or more non-blood-features in the target based on a difference in a slope of the optical attenuation with respect to wavelength corresponding to the blood or the one or more blood-features from a slope of optical attenuation with respect to wavelength corresponding to the one or more non-blood-features between a center of the first wavelength range and a center of the second wavelength range.

13. The method of claim 1 , wherein performing OCT scanning comprises performing a plurality of OCT scans (a plurality of A-scans) on a plurality of locations of the target; and wherein each scan (an A-scan) of the plurality of A-scans comprises illuminating a location of the plurality of scanned locations of the target via the sample optical path.

14. The method of claim 13 , wherein each location of the plurality of scanned locations substantially corresponds to only a single A-scan.

15. The method of claim 1 , wherein the OCT scanning is performed using a flexible probe, and wherein at least a portion of each of the reference optical path and the sample optical path is within the flexible probe.

16. The method of claim 1 , further comprising determining a concentration of a molecular marker in a bodily fluid in the imaged target, quantifying a flow of a bodily fluid in the imaged target, performing angiography of the target, and/or performing endoscopy.

17. A method for imaging a target comprising steps of:

performing optical coherence tomography (OCT) scanning on the target with one or more beams of source light, the one or more beams of source light comprising a plurality of wavelengths; wherein performing OCT scanning comprises:

providing the source light to a reference optical path and to a sample optical path, wherein providing the source light to a sample optical path comprises illuminating the target with the source light; and

recording interference data corresponding to an interaction of a light from the reference optical path and a light from the sample optical path;

processing the interference data, comprising:

determining at least a first Fourier transform and a second Fourier transform from the interference data; wherein the first Fourier transform corresponds to a first sampling window and the second Fourier transform corresponds to a second sampling window;

determining at least one spectral contrast OCT (SC-OCT) characteristic based on the at least the first Fourier transform and the second Fourier transform;

performing a depth integration using the SC-OCT characteristic and generating a depth-integrated SC-OCT (DI-SC-OCT) image, wherein the SC-OCT image comprises a plurality of pixels and wherein performing depth integration comprises integrating data corresponding to each of the plurality of pixels along a depth and multiplying by data corresponding to the inverse of the at least one of the first Fourier transform and the second Fourier transform; and

identifying blood or one or more blood-features in the target based on an optical attenuation of light in or associated with the sample optical path by the blood or the one or more blood-features.