A forward imaging endoscope for optical coherence tomography angiography (OCTA) featuring a piezoelectric fiber scanner is presented. Imaging is performed with an optical coherence tomography (OCT) system incorporating an akinetic light source with a center wavelength of 1300 nm, bandwidth of 90 nm and A-line rate of 173 kHz. The endoscope operates in contact mode to avoid motion artifacts, in particular, beneficial for OCTA measurements, and achieves a transversal resolution of 12 μm in air at a rigid probe size of 4 mm in diameter and 11.3 mm in length. A spiral scan pattern is generated at a scanning frequency of 360 Hz to sample a maximum field of view of 1.3 mm. OCT images of a human finger as well as visualization of microvasculature of the human palm are presented both in two and three dimensions. The combination of morphological tissue contrast with qualitative dynamic blood flow information within this endoscopic imaging approach potentially enables improved early diagnostic capabilities of internal organs for diseases such as bladder cancer.
Journal of biophotonics. 2019 Jan 16 [Epub ahead of print]
Lara M Wurster, Ronak N Shah, Fabian Placzek, Simon Kretschmer, Michael Niederleithner, Laurin Ginner, Jason Ensher, Michael P Minneman, Erich E Hoover, Hans Zappe, Wolfgang Drexler, Rainer A Leitgeb, Çağlar Ataman
Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria., Gisela and Erwin Sick Chair of Micro-optics, Department of Microsystems Engineering, University of Freiburg, Freiburg, Germany., INSIGHT Photonics Solution, Inc., Lafayette, Colorado.