title: Hematocrit dependence of flow signal in optical coherence tomography angiography.
abstract: The hematocrit dependence of flow signal (split-spectrum amplitude decorrelation angiography-SSADA decorrelation value) was investigated in this paper. Based on the normalized field temporal correlation function and concentration dependent particle scattering properties, the relationship between hematocrit and flow signal was analytically derived. Experimental verification of the relationship was performed with custom-designed microfluidic chips and human blood with 45%, 40% and 32% hematocrit. It was found that, in large flow channels and blood vessels, the normal hematocrit is near the decorrelation saturation point and therefore a change in hematocrit has little effect on the SSADA decorrelation value (flow signal). However, in narrow channels in the capillary size range, the effective hematocrit (adjusted for the overlap between OCT beam and channel) is in the range of 6.7-9.5% and therefore variation in hematocrit does significantly affect the flow signal.
authors.affiliation: Casey Eye Institute, Oregon Health and Science University,3375 SW Terwilliger Blvd, Portland, Oregon, 97239, USA; Co-first authors.
authors.forename: Jianlong
authors.initials: J
authors.lastname: Yang
authors.affiliation: Casey Eye Institute, Oregon Health and Science University,3375 SW Terwilliger Blvd, Portland, Oregon, 97239, USA; Co-first authors.
authors.forename: Johnny
authors.initials: J
authors.lastname: Su
authors.affiliation: Casey Eye Institute, Oregon Health and Science University,3375 SW Terwilliger Blvd, Portland, Oregon, 97239, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.affiliation: Casey Eye Institute, Oregon Health and Science University,3375 SW Terwilliger Blvd, Portland, Oregon, 97239, USA.
authors.forename: Silu
authors.initials: S
authors.lastname: Men
authors.affiliation: Casey Eye Institute, Oregon Health and Science University,3375 SW Terwilliger Blvd, Portland, Oregon, 97239, USA.
authors.forename: Yali
authors.initials: Y
authors.lastname: Jia
authors.affiliation: Casey Eye Institute, Oregon Health and Science University,3375 SW Terwilliger Blvd, Portland, Oregon, 97239, USA.
authors.forename: David
authors.initials: D
authors.lastname: Huang
authors.affiliation: Casey Eye Institute, Oregon Health and Science University,3375 SW Terwilliger Blvd, Portland, Oregon, 97239, USA.
authors.forename: Gangjun
authors.initials: G
authors.lastname: Liu
keywords: (110.4500) Optical coherence tomography; (170.3880) Medical and biological imaging; (170.4460) Ophthalmic optics and devices