Feature Of The Week 9/5/10: Record Breaking OCT Volumetric Image Acquisition Rates by Researchers at Ludwig Maximilians University
Feature Of The Week 9/5/10: As the 2010 academic years begins OCT News will resume its “Feature Of The Week” section. This year starts with an exciting submission by Dr. Robert Huber’s research group at Ludwig-Maximilians-Universität in Munich on record breaking OCT volumetric image acquisition rates that were hard to imagine just a few years ago.
Currently there is an ongoing debate about the optimum imaging speed of Optical Coherence Tomography (OCT) systems, considering the tradeoff between speed and image quality. Huge efforts have been made to push the imaging speed of OCT. This includes the application of faster line scan cameras for spectral domain (SD-) OCT and the development of swept source lasers with faster sweep repetition rate. Current high speed research systems achieve up to ~400kHz scan rate.
Dr. Robert Huber and his group of researchers from the Ludwig-Maximilians-Universität in Munich have put a great effort into pushing the OCT line rate towards the ultimate speed limit while maintaining good image quality. Systematic optimization of numerous core components in their OCT system allows them to achieve record-breaking OCT A-scan rates of up to 20.8MHz with good image quality.
As recently published by Wolfgang Wieser, Benjamin Biedermann, Thomas Klein, Christoph Eigenwillig, and Robert Huber, their system has a 4-spot beam scanning unit where each spot on the sample provides 1.0, 2.6 or 5.2MHz depth scan rate, resulting in a total 3D rate of up to 20.8 million lines per second at a sustained voxel rate of 4.5Gvoxels/s. Shot noise limited sensitivity of ~100dB and an axial resolution of ~10µm in tissue is achieved. The key enabling technology in their OCT system is a low noise Fourier Domain Mode Locked (FDML) laser with a special home-built high speed Fabry-Perot filter running at 325kHz. Subsequent buffering, a technique to increase the sweep rate by time multiplexing of the individual sweeps, increases the sweep rate beyond 1MHz.
Some of the potential advantages of multi-megahertz OCT are demonstrated in a series of imaging examples. Absence of any motion artifacts, improved image quality by advanced averaging protocols and no evident fringe washout indicate the benefits of multi-megahertz OCT.
For more information see recent Article. Courtesy of Dr. Robert Huber.