Team OCT-opus

A Deep Learning Algorithm to Enhance Retinal Images

2020 University of Waterloo Software Engineering capstone design project

Our goal: Develop an algorithm that can be used to infer blood flow from OCT cross-section images of human retinas, from only 1 cross-section per spot, captured by Prof. Bizheva's lab. The sequence of inferred cross-sections can then be combined to form a vascular map of the retina, which empowers clinicians to perform diagnosis and monitoring of diseases affecting the eye.
Our solution: A deep learning based image-to-image translation algorithm using the pix2pix cGAN architecture. The end result is that our predicted images result in vascular maps that resemble ground truth images that were created using the optical microangiography (OMAG) algorithm on multiple acquisitions of each spot. This visual success is mirrored by the quantitative comparison with the ground truth using k-folds cross-validation (k=5, 65 eyes of data) on sedated rat images, revealing a structural similarity index (SSIM) of 0.62.
B-scan example
Structural cross-section (B-scan)

An example of an input structural image.

Inferred image example
Predicted functional cross-section

Our algorithm's corresponding output enhancing visibility of vasculature.

Real OMAG example
Functional cross-section from OMAG algorithm

The ground truth image, obtained from the optical microangiography (OMAG) algorithm, which performs temporal decorrelation of 4 adjacent B-scan images from repeated acquisitions of the same spot.

B-scan example vascular map
En-face vascular map from structural cross-sections (B-scans)
Inferred image example vascular map
En-face vascular map from predicted functional cross-sections
Real OMAG example vascular map
En-face vascular map from OMAG images
Want to hear more?
Take a look at our capstone symposium presentation slides and keep an eye on the 2020 SPIE O+P conference proceedings.