作者: Brett E Bouma , G.J Tearney
DOI: 10.1016/S1076-6332(03)80465-8
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摘要: Recent advances in optical fiber and wave-guide technologies have led to the availability of clinically viable coherence tomography (OCT) systems. OCT provides cross-sectional images tissue with a resolution approximately 10 m. Its relatively shallow depth penetration (approximately 2–3 mm) requires use fiberoptic catheters endoscopes for accessing internal organs, but flexible, narrow-diameter probes are readily constructed standard telecommunications (diameter, 250 m). studies described imaging several human organ This article reviews current technology an overview recent gastroenterology cardiology. Imaging techniques such as radiography, computed tomography, magnetic resonance (MR) imaging, ultrasound (US) allow noninvasive investigation largescale structures body, resolutions ranging from 100 m 1 mm. For many disease processes, however, including cancer its early stages, higher is necessary accurate diagnosis. In addition, some clinical screening procedures, random biopsies detection high-grade dysplasia Barrett esophagus, could be improved by high-resolution, technique determine which biopsy site corresponds most severe disease. Finally, locations where cannot performed because results would catastrophic (eg, coronary arteries), To address these other problems situ approaching that used conventional histologic studies. OCT, first introduced 1991 (1), can obtain axial (depth) measures path length traveled interrogating beam incident on sample using known interferometry (1,2). process commonly accomplished dividing source light into two identical beams Michelson interferometer directing one reference mirror location. When returns both it recombined at detector, interference between registered. The temporally incoherent allows distance determined, since occur only when arrives detector simultaneously. or system determined property referred length. With advanced femtosecond laser systems, low few micrometers (3–5). A single line scan image obtained changing delay arm recording modulation amplitude function delay. Transverse scanning across specimen during data each lateral location entire two-dimensional formed. center wavelength 850 nm, was posterior anterior Acad Radiol 2002; 9:942–953