Imaging skin pathology with polarized light
Imaging skin pathology with polarized light
复制标题
DOI：
10.1117/1.1484498
复制
发表时间：
2002-07-01
影响因子：
3.5
通讯作者：
Lee, K
中科院分区：
文献类型：
--
作者：
Jacques, SL;Ramella-Roman, JC;Lee, K
照射皮肤的线偏振光被表层反向散射，并被双折射胶原纤维快速去偏振。可以将这种表面反向散射光与由深入穿透到真皮中的光主导的总漫反射光区分开。该方法涉及通过相机前面的分析线性偏振器获取两个图像，一个图像（I-Par）是用平行于照明偏振取向的分析器获取的，一个图像（I-per）是用垂直于照明取向的分析器获取的。创建基于偏振比Pol =（I-par - I-per）/（I-par + I-per）的图像。本文比较了正常的光图像，代表的I-PER，和Pol图像的各种皮肤病变的试点临床研究，使用非相干可见光谱光。图像包括色素沉着皮肤部位（雀斑、纹身、色素痣）和非色素沉着皮肤部位[非色素沉着皮内痣、神经纤维瘤、光化性角化病、恶性基底细胞癌、鳞状细胞癌、血管异常（静脉湖）、烧伤疤痕]。从剃刀刀片投射到前臂皮肤部位上的阴影的图像说明了阴影边缘附近的Pol值的行为。在阴影边缘附近，Pol的值大约加倍，因为没有I-per光子被阴影区域表面散射到阴影边缘像素中，而I-par光子直接从这些像素的表面层反向散射。该结果表明，Pol像素之间的串扰的皮肤中的点扩散函数具有约390 μ m的半高半宽。(C)2002年，美国光电仪器工程师学会。
Linearly polarized light that illuminates skin is backscattered by superficial layers and rapidly depolarized by birefringent collagen fibers. It is possible to distinguish such superficially backscattered light from the total diffusely reflected light that is dominated by light penetrating deeply into the dermis. The method involves acquisition of two images through an analyzing linear polarizer in front of the camera, one image (I-Par) acquired with the analyzer oriented parallel to the polarization of illumination and one image (I-per) acquired with the analyzer oriented perpendicular to the illumination. An image based on the polarization ratio, Pol = (I-par - I-per)/(I-par + I-per), is created. This paper compares normal light images, represented by I-per, and Pol images of various skin pathologies in a pilot clinical study using incoherent visible-spectrum light. Images include pigmented skin sites (freckle, tattoo, pigmented nevi) and unpigmented skin sites [nonpigmented intradermal nevus, neurofibroma, actinic keratosis, malignant basal cell carcinoma, squamous cell carcinoma, vascular abnormality (venous lake), burn scar]. Images of a shadow cast from a razor blade onto a forearm skin site illustrate the behavior of Pol values near the shadow edge. Near the shadow edge, Pol approximately doubles in value because no I-per photons are superficially scattered into the shadow-edge pixels by the shadow region while I-par photons are directly backscattered from the superficial layer of these pixels. This result suggests that the point spread function in skin for cross-talk between Pol pixels has a half-width-half-max of about 390 mum. (C) 2002 Society of Photo-Optical Instrumentation Engineers.