Ertefai S, Profio A E
Med Phys. 1985 Jul-Aug;12(4):393-400. doi: 10.1118/1.595701.
Diaphanography is an imaging technique using transillumination with visible and near-infrared radiation, and a video camera, to diagnose breast disease, including cancer. Originally based on luminance contrast only, there is now interest in false-color multispectral imaging in selected spectral bands to improve tissue differentiation. Some success has been achieved, but the scientific basis for the results was unknown. This research is concerned with measurements of the diffuse transmittance of breast tissues as a function of wavelength in the 600-1060 nm range (and calculations of contrast with a one-dimensional diffusion theory model). Carcinoma and glandular tissues were found to have similar spectral transmittances with an increase in transmittance between 750 and 900 nm, and an absorption window around 960 nm. Adipose tissue showed a distinct transmittance minimum at 930 nm. In vivo measurement of an intact normal breast showed a minimum at about 825 nm, as yet unexplained. The transmittance data and reflectance data were used to derive the scattering and absorption coefficients. The diffusion length was also determined from radiance versus depth measurements. These coefficients were used for calculations of contrast in a one-dimensional slab model, with and without a layer of cancerous tissue positioned between two slabs of normal tissue.
透照造影术是一种成像技术，它利用可见光和近红外辐射的透照以及摄像机来诊断乳腺疾病，包括癌症。最初仅基于亮度对比度，现在人们对选定光谱波段的伪彩色多光谱成像感兴趣，以改善组织区分。已经取得了一些成功，但结果的科学依据尚不清楚。本研究关注乳腺组织在600 - 1060纳米范围内的漫透射率随波长的测量（以及用一维扩散理论模型计算对比度）。发现癌组织和腺组织具有相似的光谱透射率，在750至900纳米之间透射率增加，在960纳米左右有一个吸收窗口。脂肪组织在930纳米处显示出明显的透射率最小值。对完整正常乳房的体内测量显示在约825纳米处有一个最小值，其原因尚待解释。透射率数据和反射率数据用于推导散射系数和吸收系数。扩散长度也通过辐射率与深度测量来确定。这些系数用于在一维平板模型中计算对比度，模型中有或没有一层癌组织位于两块正常组织平板之间。
