Open Collections

Maloufi, Sina

University of British Columbia

Optical coherence tomography (OCT) is a non-invasive imaging modality that provides high-resolution, three-dimensional images of biological tissue. Since its introduction in the 1990s, it has gained widespread adoption in ophthalmology, and it has also garnered interest in other clinical applications, such as dentistry, endoscopy, and dermatology. More recently, functional extensions of OCT have been developed that allow not only for traditional structural imaging, but also for imaging with functional contrasts in polarization. Skin cancer is a prevalent health burden in the western world, and it is currently diagnosed primarily through an invasive biopsy. As a non-invasive imaging modality, OCT can potentially result in faster skin disease diagnosis and improve quality of care. Studies have shown that OCT can be successful in diagnosing skin cancers such as basal cell carcinoma and squamous cell carcinoma, but traditional OCT has had difficulties in diagnosing melanoma. The further study of OCT’s functional extensions could solve this potential gap. This thesis focuses on Jones matrix polarization-sensitive OCT (PS-OCT), which allows for the simultaneous acquisition of multiple contrasts in intensity, phase retardation, local birefringence, and degree of polarization uniformity (DOPU). Algorithms and methods developed for PS-OCT are explored and show that advanced quantification of skin properties is possible using polarization measurements. We were able to demonstrate that polarization-based measurements are more sensitive to roughness than traditional OCT, and that specific skin layers exhibit unique polarization properties. Finally, A clinical pilot study with 18 healthy volunteers is presented in this thesis. Different skin locations in the body can be differentiated based on their polarization properties, and it is shown that PS-OCT is sensitive to changes related to aging. Additionally, case studies of eczema and vitiligo are examined with PS-OCT, and it is demonstrated that PS-OCT can differentiate features associated with both skin diseases. Our study shows that PS-OCT has high potential for applications in skin disease diagnosis.

Text

2023-10-18

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/86201

Biomedical Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/