Detectability of Absorption and Reduced Scattering Coefficients in Frequency-Domain Measurements Using a Realistic Head Phantom

Sensors

Xiaofeng Zhang¹ 

[1]Department of Radiology, Duke University Medical Center, DUMC 3808, Durham, NC 27710, USA

关键词: near infrared;    absorption;    scattering;    fast signal;    detectability;    sensitivity;    frequency domain;    phantom;    human head;   

DOI  :  10.3390/s130100152

来源: mdpi

【 摘 要 】

Detection limits of the changes in absorption and reduced scattering coefficients were investigated using a frequency-domain near-infrared system in a realistic head phantom. The results were quantified in terms of the maximum detectable depth for different activation volumes in the range of 0.8–20 microliters. The non-linear relation between the maximum detectable depth and the magnitude of changes in the absorption coefficient conform well with the Born approximation to the diffusion equation. The minimal detectable changes in the reduced scattering coefficient measured in terms of the phase signal were found to be approximately twice as large as that of the absorption coefficient using the AC signal for the same volume and at the same depth. The phase delay, which can be used to quantify the fast neuronal optical response in the human brain, showed a linear dependence on the reciprocal of the reduced scattering coefficient, as predicted by the Rytov approximation.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.