Li Wenjing, Venkataraman Sankar, Gustafsson Ulf, Oyama Jody C, Ferris Daron G, Lieberman Rich W
STI Medical Systems, 733 Bishop Street, Honolulu, Hawaii 96813, USA.
J Biomed Opt. 2009 Jan-Feb;14(1):014020. doi: 10.1117/1.3079810.
Cervical intraepithelial neoplasia (CIN) exhibits certain morphologic features that can be identified during a colposcopic exam. Immature metaplastic and dysplastic cervical squamous epithelia turn white after application of acetic acid during the exam. The whitening process occurs visually over several minutes and subjectively helps to discriminate between dysplastic and normal tissue. Digital imaging technologies enable us to assist the physician in analyzing acetowhite (acetic-acid-induced) lesions in a fully automatic way. We report a study designed to measure multiple parameters of the acetowhitening process from two images captured with a digital colposcope. One image is captured before the acetic acid application, and the other is captured after the acetic acid application. The spatial change of the acetowhitening is extracted using color and texture information in the post-acetic-acid image; the temporal change is extracted from the intensity and color changes between the post-acetic-acid and pre-acetic-acid images with an automatic alignment. In particular, we propose an automatic means to calculate an opacity index that indicates the grades of temporal change. The imaging and data analysis system is evaluated with a total of 99 human subjects. The proposed opacity index demonstrates a sensitivity and specificity of 94 and 87%, respectively, for discriminating high-grade dysplasia (CIN2+) from normal and low-grade subjects, considering histology as the gold standard.
宫颈上皮内瘤变（CIN）具有某些可在阴道镜检查中识别的形态学特征。在检查过程中，未成熟的化生和发育异常的宫颈鳞状上皮在涂抹醋酸后会变白。变白过程在几分钟内肉眼可见，主观上有助于区分发育异常组织和正常组织。数字成像技术使我们能够以全自动方式协助医生分析醋酸白（醋酸诱导）病变。我们报告了一项旨在从用数字阴道镜拍摄的两张图像中测量醋酸白变过程多个参数的研究。一张图像在涂抹醋酸前拍摄，另一张在涂抹醋酸后拍摄。利用醋酸后图像中的颜色和纹理信息提取醋酸白变的空间变化；通过自动对齐从醋酸后图像和醋酸前图像之间的强度和颜色变化中提取时间变化。特别是，我们提出了一种自动方法来计算表示时间变化等级的不透明度指数。成像和数据分析系统对总共99名受试者进行了评估。以组织学为金标准，所提出的不透明度指数在区分高级别发育异常（CIN2+）与正常和低级别受试者方面分别表现出94%和87%的敏感性和特异性。
