Influences of tissue absorption and scattering on diffuse correlation spectroscopy blood flow measurements.
Influences of tissue absorption and scattering on diffuse correlation spectroscopy blood flow measurements.
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DOI：
10.1364/boe.2.001969
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发表时间：
2011-07-01
影响因子：
3.4
通讯作者：
Yu G
中科院分区：
文献类型：
--
作者：
Irwin D;Dong L;Shang Y;Cheng R;Kudrimoti M;Stevens SD;Yu G
在这项研究中，我们评估了光学性质假设对近红外漫相关光谱(DCS)流动指数测量的影响。吸收系数(µa)和折合散射系数(µS‘)这两种光学特性使用液体模体独立变化，并使用双波长分布式控制系统流动装置和商用频域组织血氧仪相结合的混合光学系统与流动指数同时测量。在两个波长(785和830 nm)下，使用测量的µa和µS‘或假设常数µa和µS’来计算分散控制系统的流量指数。不准确的S的假设导致的流动指数误差比不准确的µa大得多。低估/高估了−35%/+175%的µS会导致+110%/−80%的流动指数误差，而低估/高估了−40%/+150%的µa会导致−20%/+40%的流动指数误差，无论使用什么波长。对一项涉及人类头颈部肿瘤的临床研究的检查表明，高达+280%的血流指数误差是由患者之间的光学特性变化引起的。这些发现表明，涉及µa和µS显著变化的研究应同时测量血流指数和光学性质，以准确提取血流信息。
In this study we evaluate the influences of optical property assumptions on near-infrared diffuse correlation spectroscopy (DCS) flow index measurements. The optical properties, absorption coefficient (µa) and reduced scattering coefficient (µs′), are independently varied using liquid phantoms and measured concurrently with the flow index using a hybrid optical system combining a dual-wavelength DCS flow device with a commercial frequency-domain tissue-oximeter. DCS flow indices are calculated at two wavelengths (785 and 830 nm) using measured µa and µs′ or assumed constant µa and µs′. Inaccurate µs′ assumptions resulted in much greater flow index errors than inaccurate µa. Underestimated/overestimated µs′ from −35%/+175% lead to flow index errors of +110%/−80%, whereas underestimated/overestimated µa from −40%/+150% lead to −20%/+40%, regardless of the wavelengths used. Examination of a clinical study involving human head and neck tumors indicates up to +280% flow index errors resulted from inter-patient optical property variations. These findings suggest that studies involving significant µa and µs′ changes should concurrently measure flow index and optical properties for accurate extraction of blood flow information.