May 16, 2008
New growth for optical coherence tomography
Optical coherence tomography is an emerging medical imaging technology with an ever growing list of applications. Marie Freebody speaks to James Fujimoto to find out more.
James Fujimoto is a professor at the Massachusetts Institute of Technology in the US and is one of the key players responsible for the invention and development of optical coherence tomography (OCT) in the early 1990s. Fujimoto also has an active commercial side and has co-founded two companies, one of which was acquired by Zeiss and led to the first OCT instrument for clinical ophthalmology. The second company is currently developing intravascular and endoscopic OCT.
Can you explain how OCT works?
OCT enables micron-scale, cross-sectional and three-dimensional (3D) imaging of biological tissues in situ and in real time. The technique measures the echo time delay and intensity of backscattered light using interferometry with broadband light sources or with frequency swept lasers. The approach is analogous to ultrasound, except that imaging is performed by measuring light rather than sound. The imaging depths are typically around 2 mm, which is shallow compared with ultrasound. However, OCT can provide much higher image resolutions of a few microns.