Methods, systems and computer program products for mixed-density optical coherence tomography (OCT) imaging
Methods, systems and computer program products are provided for acquiring an image set using optical coherence tomography (OCT). A first portion of a defined volume is scanned at a low-density sampling rate to obtain a plurality of low-density frames. A second portion of the defined volume is scanned at a high-density sampling rate, higher than the low-density sampling rate, to obtain at least one high-density frame. The low-density frames and the at least one high-density frame are combined to provide a complete mixed-density image set.
1. A method of acquiring an image set using optical coherence tomography (OCT), comprising:
defining a contiguous scanning sequence structured to acquire at least two portions of a defined volume;
scanning a first portion of the at least two portions of the defined volume at a low-density sampling rate to obtain a plurality of low-density frames;
scanning a second portion of the at least two portions of the defined volume at a high-density sampling rate, higher than the low-density sampling rate, to obtain at least one high-density frame; and
registering the low-density frames and the at least one high-density frame to provide a complete mixed-density image set.
2. The method of claim 1 :
wherein the at least one high-density frame comprises a plurality of high-density frames; and
wherein scanning a first portion and scanning a second portion comprises scanning over the defined volume such that the plurality of high-density frames are separated by the plurality of low-density frames.
3. The method of claim 2 , wherein scanning the first portion is preceded by:
defining the volume to be measured;
defining a sampling density obtaining the plurality of low-density frames;
defining a number low-density frames to be obtained between each of the high-density frames;
defining a sampling density for obtaining the plurality of high-density frames; and
defining a number of high-density frames to be obtained between each of the defined number of the plurality of low-density frames.
4. The method of claim 3 , wherein the number of high-density frames obtained between each of the plurality of low-density frames is greater than one.
5. The method of claim 4 , wherein the number of high-density frames obtained between each of the plurality of low-density frames comprises a series of contiguous high-density frames.
6. The method of claim 5 , wherein scanning the second portion of the defined volume to provide the series of contiguous high-density frames further comprises registering and averaging the acquired high-density frames.
7. The method of claim 6 , wherein scanning the second portion of the defined volume to provide the series of contiguous high-density frames further comprises acquiring the high-density frames using an offset between successive frames.
8. The method of claim 1 , wherein the registering comprises registering the obtained low-density frames with the at least one high-density frame to provide a single contiguous registered image.
9. The method of claim 1 , further comprising creating a mixed-density volume projection intensity image from the complete mixed-density image set.
10. The method of claim 1 , wherein total imaging duration is from about 1.0 to about 5.0 seconds.
11. The method of claim 1 , wherein the low-density sampling rate is from about 80 frames per second to about 400 frames per second and wherein the high-density sampling rate is from about 10 frames per second to about 80 frames per second.
12. The method of claim 1 , wherein the high-density sampling rate exceeds the low density sampling rate by a factor from about 2.0 to about 10.0.
13. The method of claim 1 , wherein defining comprises defining the contiguous scanning sequence without any feedback from the image.
14. A optical coherence tomography (OCT) system for acquiring a mixed density image set, comprising:
at least one processor configured to pre-define a contiguous scanning sequence structured to acquire at least two portions of a defined volume before the defined volume is scanned, the at least one processor including:
a low-density scanning module configured to scan a first portion of the at least two portions of the defined volume at a low-density sampling rate to obtain a plurality of low-density frames;
a high-density scanning module configured to scan a second portion of the at least two portions of the defined volume at a high-density sampling rate, higher than the low-density sampling rate, to obtain at least one high-density frame; and
a combination module configured to register the low-density frames and the at least one high-density frame to provide a complete mixed-density image set.
15. The system of claim 14 :
wherein the at least one high-density frame comprises a plurality of high-density frames; and
wherein the high-density scanning module and the low-density scanning module are further configured to scan over the defined volume such that the plurality of high-density frames are separated by the plurality of low-density frames.
16. The system claim 15 :
wherein the low-density scanning module or the high-density scanning module is further configured to define the volume to be measured;
wherein the low-density scanning module is configured to define a sampling density for obtaining the plurality of low-density frames and a number of low-density frames to be obtained between each of the high-density frames; and
wherein the high-density scanning module is configured to define a sampling density for obtaining the plurality of high-density frames and a number of high-density frames to be obtained between each of the defined number of the plurality of low-density frames.
17. The system of claim 16 , wherein the number of high-density frames obtained between each of the plurality of low-density frames comprises a series of contiguous high-density frames.
18. The system of claim 17 , wherein the high-density scanning module is further configured to scan the second portion of the defined volume to provide the series of contiguous high-density frames by registering and averaging the acquired high-density frames.
19. The system of claim 18 , wherein the high-density scanning module is further configured to scan the second portion of the defined volume to provide the series of contiguous high-density frames by acquiring the high-density frames using an offset between successive frames.
20. The system of claim 14 , wherein the combination module is further configured to register the obtained low-density frames with the at least one high-density frame to provide a single contiguous registered image.
21. The system of claim 14 , further comprising an image creation module configured to create a mixed-density volume projection intensity image from the complete mixed-density image set.
22. The system of claim 14 , wherein total imaging duration is from about 1.0 to about 5.0 seconds.
23. The system of claim 14 , wherein the low-density scanning module is configured to scan the defined volume at the low-density sampling rate of from about 80 frames per second to about 400 frames per second and wherein the high-density scanning module is configured to scan the defined volume at the high-density sampling rate of from about 10 frames per second to about 80 frames per second.
24. The system of claim 14 , wherein the high density sampling rate exceeds the low density sampling rate by a factor from about 2.0 to about 10.0.
25. The system of claim 14 , wherein the system is configured to transition between low-density mode of operation of the low-density scanning module and high-density mode of operation of the high-density scanning module smoothly such that spatial registration between successive frames is maintained.
26. The system of claim 14 , wherein the processor is further configured to define the contiguous scanning sequence without any feedback from the image.
27. A computer program product for acquiring an image set using optical coherence tomography (OCT), the computer program product comprising:
a non-transitory computer-readable storage medium having computer-readable program code embodied in the medium, the computer-readable program code comprising:
computer readable program code configured to define a contiguous scanning sequence structured to acquire at least two portions of a defined volume before the defined volume is scanned;
computer readable program code configured to scan a first portion of a defined volume at a low-density sampling rate to obtain a plurality of low-density frames;
computer readable program code configured to scan a second portion of the defined volume at a high-density sampling rate, higher than the low-density sampling rate, to obtain at least one high-density frame; and
computer readable program code configured to register the low-density frames and the at least one high-density frame to provide a complete mixed-density image set.
28. The computer program product of claim 27 :
wherein the at least one high-density frame comprises a plurality of high-density frames; and
wherein computer readable program code configured to scan a first portion and a second portion comprises computer readable program code configured to scan over the defined volume such that the plurality of high-density frames are separated by the plurality of low-density frames.
29. The computer program product of claim 28 , further comprising:
computer readable program code configured to define the volume to be measured;
computer readable program code configured to define a sampling density for obtaining the plurality of low-density frames;
computer readable program code configured to define a number of low-density frames to be obtained between each of the high-density frames;
computer readable program code configured to define a sampling density for obtaining the plurality of high-density frames; and
computer readable program code configured to define a number of high-density frames to be obtained between each of the defined number of the plurality of low-density frames.
30. The computer program product of claim 29 , wherein the number of high-density frames obtained between each of the plurality of low-density frames comprises a series of contiguous high-density frames.
31. The computer program product of claim 30 , wherein the computer readable program code configured to scan the second portion of the defined volume to provide the series of contiguous high-density frames further comprises computer readable program code configured to register and average the acquired high-density frames.
32. The computer program product of claim 30 , wherein the computer readable program code configured to scan the second portion of the defined volume to provide the series of contiguous high-density frames further comprises computer readable program code configured to acquire the high-density frames using an offset between successive frames.
33. The computer program product of claim 27 , further comprising computer readable program code configured to create a mixed-density volume projection intensity image from the complete mixed-density image set.
34. The computer program product of claim 27 , wherein the computer readable program code configured to define further comprises computer readable program code configured to define the contiguous scanning sequence without any feedback from the image.