Optical coherence tomography in digestive diseases: advances and clinical applications

Optical coherence tomography (OCT) has emerged as a transformative imaging modality in gastroenterology, offering micrometer-scale resolution for visualizing gastrointestinal tract structures with unprecedented detail. The ability of OCT to provide "optical biopsy" capabilities without tissue removal has revolutionized the diagnostic approach to gastrointestinal diseases, particularly for early cancer detection and characterization of mucosal abnormalities. The clinical utility of OCT in gastroenterology spans multiple applications including disease detection, differentiation of pathological states, and guidance for endoscopic therapies. Unlike traditional histopathology which requires tissue removal and processing, OCT enables real-time, in vivo assessment of gastrointestinal mucosa and submucosa with near-histological resolution. Several key technological innovations have driven OCT's adoption in gastrointestinal imaging. The development of miniaturized endoscopic probes capable of high-speed circumferential scanning has enabled comprehensive evaluation of the gastrointestinal lumen. Furthermore, the integration of OCT with conventional endoscopy systems has facilitated its clinical translation, allowing gastroenterologists to combine macroscopic and microscopic evaluation during routine procedures. Recent advances in image processing algorithms, including spectral estimation techniques, have further enhanced resolution beyond the fundamental limits imposed by light source coherence length, enabling visualization of cellular-level features in gastrointestinal tissues.