Pifferi Antonio, Swartling Johannes, Chikoidze Ekaterine, Torricelli Alessandro, Taroni Paola, Bassi Andrea, Andersson-Engels Stefan, Cubeddu Rinaldo
Politecnico di Milano, ULTRAS-INFM, INF-CNR, Dipartimento di Fisica, P. L. da Vinci 32, I-20133, Milano, Italy.
J Biomed Opt. 2004 Nov-Dec;9(6):1143-51. doi: 10.1117/1.1802171.
The first, to our knowledge, in-vivo broadband spectroscopic characterization of breast tissue using different interfiber distances as well as transmittance measurements is presented. Absorption and scattering properties are measured on six healthy subjects, using time-resolved diffuse spectroscopy and an inverse model based on the diffusion equation. Wavelength-tunable picosecond-pulse lasers and time-correlated single-photon counting detection are employed, enabling fully spectroscopic measurements in the range 610 to 1040 nm. Characterization of the absorption and reduced scattering coefficients of breast tissue is made with the aim of investigating individual variations, as well as variations due to different measurement geometries. Diffuse reflectance measurements at different interfiber distances (2, 3, and 4 cm) are performed, as well as measurements in transmittance mode, meaning that different sampling volumes are involved. The results show a large variation in the absorption and scattering properties depending on the subject, correlating mainly with the water versus lipid content of the breast. Intrasubject variations, due to different interfiber distances or transmittance modes, correlate with the known structures of the breast, but these variations are small compared to the subject-to-subject variation. The intrasubject variations are larger for the scattering data than the absorption data; this is consistent with different spatial localization of the measurements of these parameters, which is explained by the photon migration theory.
据我们所知，首次展示了使用不同光纤间距以及透过率测量对乳腺组织进行的体内宽带光谱表征。使用时间分辨漫射光谱和基于扩散方程的反演模型，对六名健康受试者的吸收和散射特性进行了测量。采用波长可调谐皮秒脉冲激光器和时间相关单光子计数检测，能够在610至1040nm范围内进行全光谱测量。对乳腺组织的吸收系数和约化散射系数进行表征，目的是研究个体差异以及不同测量几何结构导致的差异。进行了不同光纤间距（2、3和4cm）的漫反射测量以及透过率模式下的测量，这意味着涉及不同的采样体积。结果表明，吸收和散射特性因受试者而异，主要与乳腺中的水和脂质含量相关。由于不同的光纤间距或透过率模式导致的受试者内部差异与乳腺的已知结构相关，但与受试者间差异相比，这些差异较小。散射数据的受试者内部差异大于吸收数据；这与这些参数测量的不同空间定位一致，光子迁移理论对此进行了解释。
