Endoscopic fourier domain optical coherence tomography for bladder cancer diagnosis

We report a newly developed endoscopic optical coherence tomography (FDEOCT) system which incorporates Fourier-domain optical coherence tomography (FDOCT) and MEMS mirror for endoscopic laser scanning to improve the frame rate and the dynamic range of the imaging system. Experimental results show that the measured axial resolution of the FDEOCT system is 10.8μm, which is identical to that of the time domain EOCT (TDEOCT) system, and approaches the theoretical limit of 9.5μm for the broadband source (BBS) employed. With the current InGaAs photodiode array, an A-scan rate of 7.7 kHz is achieved, which is 4 times higher than our current time domain system. Experimental results on normal pig bladder are presented, suggesting the ability of FDEOCT to clearly differentiate the three layers of the bladder tissue, critical to early diagnosis of flat bladder cancers.