In vivo high resolution imaging of gastrointestinal tissue using optical coherence tomography

Micron scale, cross-sectional imaging of tissue microstructure in vivo, could potentially aid the diagnosis and clinical management of disorders of the gastrointestinal tract. In this work, we demonstrate in vivo micron scale cross-sectional imaging of the rabbit gastrointestinal tract with the recently developed imaging technology, optical coherence tomography (OCT). OCT is analogous to ultrasound imaging, measuring the intensity of backreflected infrared light rather than acoustical waves (Science: 254, 681-684, 1991). To perform in vivo imaging, the OCT system has been modified for rapid data acquisition rates (4 frames/sec) and imaging is performed through an OCT endoscope (1 mm diameter). OCT imaging was performed of the esophagus and stomach of anesthetized New Zealand White Rabbits. The axial resolution was measured to be 10 μm and the signal to noise ratio was 106 dB. Images were stored in both analog and digital format. Microscopic morphologic layers such as the mucosa, submucosa, inner muscularis, outer muscularis, serosa, and supportive adipose tissue, can be identified, in addition to intramural blood vessel and glands. The rapid data acquisition rates prevent motion artifacts. This study demonstrates that in vivo imaging at micron scale resolutions can be obtained with OCT. The ability to perform in vivo imaging at a resolution comparable to conventional histopathology may represent a powerful tool for the diagnosis and management of a wide range of gastrointestinal disorders.