Optical Coherence Tomography: Future Applications in Cerebrovascular Imaging

Cross-sectional imaging of biological tissue microstructure using optical backscattering was first demonstrated in 1991.1 The technique, known as optical coherence tomography (OCT), uses low-coherence interferometry to produce a 2-dimensional image of optical scattering from tissues in a way that resembles pulse-echo imaging in ultrasound. Huang et al1 revealed promising clinical and research applications with their in vitro demonstrations of this novel imaging technique in both the peripapillary area of the retina and the coronary arteries. The first in vivo clinical application of OCT was reported in 1993, when it permitted detailed, noninvasive imaging of the anterior eye chamber, as well as other structures, such as the fovea and the optic disc of the retina.2–5 Collaboration between this pioneering group and the New England Eye Center has led to its routine use in ophthalmologic diagnostics and its subsequent commercial availability in 1996.6 Recent advancements in OCT technology have broadened its application to retinal vasculature and nontransparent tissues.7–10 OCT angiography has permitted noninvasive evaluation of retinal vascular abnormalities ranging from detecting neovascularization to quantifying ischemia.11 OCT use in areas ranging from developmental biology research to clinical applications in the fields of gastroenterology, urology, and neurosurgery have now been investigated.8,12–23 Optimization of OCT technology as an imaging modality has been achieved with the use of real-time imaging yielding greater image acquisition rates and laser light sources, which have improved image resolution.12,24–27 The recent US Food and Drug Administration approval of OCT for intravascular imaging has provided an unprecedented level of detail, on the micron level, in the evaluation of vascular pathologies that involve individual vessel wall layers.28 This has also sparked interest in the translation of the technology into the field of …