Purpose:
Rapid volumetric imaging is critical for Fourier Domain Optical Coherence Tomography (FDOCT) in order to acquire high resolution 3D data without motion artifact. We present a medical imaging interpolation technique called Compressive Sampling (CS) for rapid volumetric acquisition of retina and Optic Nerve Head (ONH) in humans and in rodents.
Methods:
The 3D volumes were acquired with a custom FDOCT system. A reduction in the acquisition time was implemented by modification of the scan pattern to acquire only a subset of the area (up to only 25%) using randomly spaced horizontal and vertical B-scans. Compressive sampling techniques were used to interpolate the missing data with high fidelity for scan time reductions of up to 73% on human ONH volumetric data.
Results:
Reconstructions using the Compressive Sampling (CS) method were performed on sparsely acquired rodent retinal images. Figure 1(A) shows images of the fully acquired rodent retinal volume. A second volume was acquired at the same location on the retina using CS with 62% of the data missing, corresponding to a reduction in scan time of 58%. A representative sparsely acquired B-scan image extracted from this volume is presented in Fig 1 (B). The reconstructed B-scan generated by application of the CS algorithm on the 3D data is presented in Fig 1 (C). The corresponding B-scan from the fully acquired volume is shown in Fig 1 (D).
Conclusions:
We demonstrated that Compressive Sampling can be used to reconstruct 3D FDOCT images with minimal degradation in quality. We showed that there is negligible effect on rodent retinal layers and on clinically relevant morphometric measurements of the human ONH. The potential outcome of this work is a significant reduction in FDOCT image acquisition time for clinical volumetric imaging applications.
Fig 1: A) Volumetric reconstruction of the full data; the shadowed frame shows the location of the B-scans on the right. B) Representative B-scan extracted from the sparsely acquired volume, and C) Compressive Sampling reconstruction. D) Corresponding B-scan from the full acquisition.
Keywords: image processing • imaging/image analysis: clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)