PMID- 32010512 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20200928 IS - 2156-7085 (Print) IS - 2156-7085 (Electronic) IS - 2156-7085 (Linking) VI - 11 IP - 1 DP - 2020 Jan 1 TI - Gabor optical coherence tomographic angiography (GOCTA) (Part II): theoretical basis of sensitivity improvement and optimization for processing speed. PG - 227-239 LID - 10.1364/BOE.380287 [doi] AB - We previously proposed a Gabor optical coherence tomography angiography (GOCTA) algorithm for spectral domain optical coherence tomography (SDOCT) to extract microvascular signals from spectral fringes directly, with speed improvement of 4 to 20 times over existing methods. In this manuscript, we explored the theoretical basis of GOCTA with comparison of experimental data using solid and liquid displacement sample targets, demonstrating that the majority of the GOCTA sensitivity advantage over speckle variance based techniques was in the small displacement range (< 10 approximately 20 microm) of the moving target (such as red blood cells). We further normalized GOCTA signal by root-mean-square (RMS) of original fringes, achieving a more uniform image quality, especially at edges of blood vessels where slow flow could occur. Furthermore, by transecting the spectral fringes and using skipped convolution, the data processing speed could be further improved. We quantified the trade-off in signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR) under various sub-spectral bands and found an optimized condition using 1/4 spectral band for minimal angiography image quality degradation, yet achieving a further 26.7 and 34 times speed improvement on GPU and CPU, respectively. Our optimized GOCTA algorithm has a speed advantage of over 140 times compared to existing speckle variance OCT (SVOCT) method. CI - (c) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement. FAU - Chen, Chaoliang AU - Chen C AD - Biophotonics and Bioengineering Lab, Department of Electrical, Computer, and Biomedical Engineering, Ryerson University, Toronto, Ontario, Canada. FAU - Shi, Weisong AU - Shi W AD - Biophotonics and Bioengineering Lab, Department of Electrical, Computer, and Biomedical Engineering, Ryerson University, Toronto, Ontario, Canada. AD - Department of Optical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, China. FAU - Ramjist, Joel AU - Ramjist J AD - Biophotonics and Bioengineering Lab, Department of Electrical, Computer, and Biomedical Engineering, Ryerson University, Toronto, Ontario, Canada. FAU - Yang, Victor X D AU - Yang VXD AD - Biophotonics and Bioengineering Lab, Department of Electrical, Computer, and Biomedical Engineering, Ryerson University, Toronto, Ontario, Canada. AD - Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada. AD - Division of Neurosurgery, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada. LA - eng PT - Journal Article DEP - 20191211 PL - United States TA - Biomed Opt Express JT - Biomedical optics express JID - 101540630 PMC - PMC6968745 COIS- The authors declare that there are no conflicts of interest related to this work. EDAT- 2020/02/06 06:00 MHDA- 2020/02/06 06:01 PMCR- 2020/01/01 CRDT- 2020/02/04 06:00 PHST- 2019/10/17 00:00 [received] PHST- 2019/12/05 00:00 [revised] PHST- 2019/12/05 00:00 [accepted] PHST- 2020/02/04 06:00 [entrez] PHST- 2020/02/06 06:00 [pubmed] PHST- 2020/02/06 06:01 [medline] PHST- 2020/01/01 00:00 [pmc-release] AID - 380287 [pii] AID - 10.1364/BOE.380287 [doi] PST - epublish SO - Biomed Opt Express. 2019 Dec 11;11(1):227-239. doi: 10.1364/BOE.380287. eCollection 2020 Jan 1.