Optical coherence tomography for coronary artery disease : analysis and applications

The aim of this thesis was to develop a software pipeline for tissue analysis in IVOCT by systematically addressing different open questions for analysis. In Chapter 2, we report on a first attempt to quantify the correlation between the position of the catheter with respect to the luminal wall and the image intensities. We implemented the Depth-Resolved (DR) model for IVOCT images in Chapter 3. In addition to the attenuation coefficient, we further extended the model to estimate a backscatter term, and proposed an algorithm to exclude the noisy region. For the first time, it was implemented in IVOCT images with fast and robust calculations. Results show that the IVOCT intensity, DR attenuation coefficient and backscatter term extracted with the reported implementation are complementary to each other in characterizing six tissue types. In Chapter 4, we applied an exact histogram specification technique to covert data generated using different vendors e.g. 8-bit Terumo data and 16-bit St. Jude data. For the application of the DR algorithm, the optical parameters were analyzed as features for the maturity of post-stenting neointima in Chapter 5. In Chapter 6, the three values were analyzed for the determination of thrombi types with high reproducibility.