Monitoring hypoxia induced changes in cochlear blood flow and hemoglobin concentration using a combined dual-wavelength laser speckle contrast imaging and Doppler optical microangiography system.

Roberto Reif,Jia Qin,Lei Shi,Alfred L Nuttall,Zhongwei Zhi,Ruikang K Wang,Suzan Dziennis,Arrate Muñoz-Barrutia

doi:10.1371/journal.pone.0052041

Roberto Reif, Jia Qin + Show 6 more

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https://doi.org/10.1371/journal.pone.0052041

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Abstract

A synchronized dual-wavelength laser speckle contrast imaging (DWLSCI) system and a Doppler optical microangiography (DOMAG) system was developed to determine several ischemic parameters in the cochlea due to a systemic hypoxic challenge. DWLSCI can obtain two-dimensional data, and was used to determine the relative changes in cochlear blood flow, and change in the concentrations of oxyhemoglobin (HbO), deoxyhemoglobin (Hb) and total hemoglobin (HbT) in mice. DOMAG can obtain three-dimensional data, and was used to determine the changes in cochlear blood flow with single vessel resolution. It was demonstrated that during a hypoxic challenge there was an increase in the concentrations of Hb, a decrease in the concentrations of HbO and cochlear blood flow, and a slight decrease in the concentration of HbT. Also, the rate of change in the concentrations of Hb and HbO was quantified during and after the hypoxic challenge. The ability to simultaneously measure these ischemic parameters with high spatio-temporal resolution will allow the detailed quantitative analysis of several hearing disorders, and will be useful for diagnosing and developing treatments.

Highlights

Several hearing disorders such as noise-induced hearing loss, age related hearing loss, sudden sensorineural hearing loss, tinnitus and Meniere’s disease, have been related to cochlear ischemia [1,2,3,4,5,6,7,8,9]
Laser Doppler flowmetry has been used to measure the relative changes of cochlear blood flow (CBF) during loud sound exposure [17], and during the use of vasodilators [18]
In this paper we propose to use a synchronized dual-wavelength laser speckle contrast imaging (DWLSCI) system [20] which is combined with a Doppler optical microangiography (DOMAG) system, to determine several cochlea ischemic parameters

Summary

Introduction

Several hearing disorders such as noise-induced hearing loss, age related hearing loss, sudden sensorineural hearing loss, tinnitus and Meniere’s disease, have been related to cochlear ischemia [1,2,3,4,5,6,7,8,9]. It has been difficult to obtain information regarding cochlea ischemia in humans given that the invasiveness of the techniques carries the risk of increasing the functional loss. Laser Doppler flowmetry has been used to measure the relative changes of cochlear blood flow (CBF) during loud sound exposure [17], and during the use of vasodilators [18]. This technique has been limited because it averages the changes in blood flow within a large volume of the cochlea (a hemisphere with a ,1–1.5 mm radius); there is uncertainty about which vessels contributed to the measured signal [19]

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