Optical coherence tomography (OCT), a non-invasive, high-resolution imaging modality, has seen an increasing role as a clinical diagnostic, screening, and therapeutic imaging method over the years. Medical specialties such as ophthalmology, interventional cardiology and gastroenterology have been able to take full advantage of OCT’s minimally invasive near-cellular depth resolution to stage and diagnose different disease states and medical conditions. Although we have seen a wide spread use of OCT in the aforementioned specialties, there remains a plethora of medical specialties that could potentially benefit from the use of a non-invasive, high-resolution imaging modality. This thesis concentrates on developing the use of OCT and analytical image processing methods to address clinical unmet needs in interventional pulmonology, head and neck cancer and dermatology. The work presented will specifically discuss nosocomial ventilator associated pneumonia, oral squamous cell carcinoma (SCC), and androgenic alopecia (AA) respectively.
Each medical condition studied required a unique imaging system and imaging probe to properly assess the presented clinical need. Ventilator associated pneumonia (VAP) utilized a high-speed Fourier domain OCT (FD-OCT) imaging system with side-viewing probe, a microscope-based fluorescence lifetime imaging (FLIM) system, and a bench top terahertz spectroscopy system. Using the three imaging modalities, the macroscopic structure of bacterial biofilm in-situ as well as biofilm bacterial phenotype composition could be resolved. OSCC required the development of a portable low-cost spectral domain OCT(SD-OCT) imaging system and low-profile forward viewing scanning probe to transport the system overseas to Bangalore, India where oral cancer has a high prevalence. Using intensity-based OCT as compared to the histology gold standard, differences between normal, dysplastic and malignant oral mucosa were determined. Lastly, androgenic alopecia better known as male or female pattern baldness, utilized a larger 3D scanning hand held microscope probe that provided a wide field of view yet a high lateral resolution to observe differences in hair shaft and hair follicle structure between varying stages of balding.
Structural intensity-based OCT biomarkers are effective in analyzing various disease conditions, as evidence by the clinical OCT imaging applications. These biomarkers provide a means of assessing and staging the state of the medical condition in the spectrum between normal and abnormal. With such an imaging tool and outlook, physicians could further guide medical intervention, determine treatment efficacy and monitor disease progression.