Pandian P S, Singh Megha
Biomedical Engineering Division, Indian Institute of Technology Madras, Chennai 600 036, India.
Indian J Exp Biol. 2010 Oct;48(10):993-1001.
Laser backscattering from biological tissues depends on their composition and blood flow. The onset of the tissue abnormalities is associated with the change in composition at a specific location which may affect laser backscattering. The objective of the present work is to detect the compositional changes in tissue-equivalent phantom of fat, prepared by mixing paraffin wax with wax colors, and to characterize these in terms of their optical parameters. For this purpose these phantoms are scanned by a multi-probe non-contact automatic laser scanning system and images of the normalized backscattered intensity (NBI) are constructed. By scanning the background subtracted image of the phantom the location of the abnormality and its size from the full width at half maximum (FWHM) are determined. The data obtained by ultrasonic technique for localization of the abnormalities are in agreement with that as obtained by the present method. The optical parameters of the abnormality are obtained by matching the measured surface profiles of the abnormality with that of the profile obtained by Monte Carlo simulation. This analysis shows the possibility of detection of changes at the onset stage in tissues as required for planning of the photodynamic therapy.
生物组织的激光背向散射取决于其组成和血流情况。组织异常的出现与特定位置的组成变化相关，这可能会影响激光背向散射。本研究的目的是检测通过将石蜡与蜡色混合制备的脂肪组织等效体模中的成分变化，并根据其光学参数对这些变化进行表征。为此，使用多探头非接触式自动激光扫描系统对这些体模进行扫描，并构建归一化背向散射强度（NBI）图像。通过扫描体模的背景扣除图像，从半高宽（FWHM）确定异常的位置及其大小。通过超声技术获得的用于异常定位的数据与本方法获得的数据一致。通过将测量的异常表面轮廓与蒙特卡罗模拟获得的轮廓进行匹配，得到异常的光学参数。该分析表明，按照光动力疗法规划的要求，在组织发病阶段检测变化是有可能的。
