Dual-energy Electronic-cleansing CT Colonography for Colon Cancer Screening

描述（申请人提供）：筛查是目前早期发现结肠癌最有效的方法。计算机断层结肠镜（CTC）或虚拟结肠镜检查已成为一种有效的非侵入性结肠癌筛查技术，可以替代光学结肠镜检查（OC）。然而，目前的CTC检查要求检查前进行肠导泻准备，这与OC的要求基本相同。在CTC检查前，与严格的肠泻准备相关的感觉不适和不便已被确定为广泛接受结肠筛查的主要障碍。将非泻性肠道准备应用于CTC检查的主要技术障碍是缺乏一种有效的电子清洗（EC）方案来减去CTC图像中标记的粪便物质，因为目前的EC方法中遇到的清洗伪影太严重，无法使非泻性CTC图像具有诊断质量。双能CT （Dual-energy CT, deCT）是一种新的成像技术，它可以根据两个同步CT在不同能量下采集的CT衰减值来区分材料。非泻性双能CTC (deCTC)，即将deCT应用于非泻性CTC图像采集，具有显著提高EC质量的潜力。在本项目中，我们将开发一种非泻性deCTC的EC方案，称为双能EC (deEC)，其中患者将进行非泻性肠准备检查并使用deCT扫描仪成像。在图像采集后，本文提出的deEC方案通过一套新的双能量背景下的图像处理方法，有效地去除CTC图像中结肠内残留的粪便物质。deCTC的材料区分能力为消除现有EC方法中存在的主要清洗伪影提供了一个新的维度，从而提供了具有诊断质量的CTC图像。为了评估目的，我们将建立一个非泻性DE-CTC数据库。拟议DE-EC方案的质量和性能将在模拟研究、人工清洁研究、息肉计算机辅助检测（CAD）研究和观察者研究中进行评估。这项研究的创新之处在于，非泻性deCTC及其deEC方案的发展尚未尝试过。建议的deEC方案的成功开发和验证将为放射科医生提供诊断质量的清洁CTC图像，用于检测结肠癌，并将患者从结肠筛查的主要关注点中解脱出来。这种deec辅助的非泻性deCTC检查可以大大提高筛查的依从性、安全性和结肠癌筛查的能力。因此，本研究将大大提高结肠息肉和癌症的筛查率和早期发现。

DESCRIPTION (provided by applicant): Screening is currently the most effective way for early detection of colonic cancer. Computed tomographic colonography (CTC), or virtual colonoscopy, has become an effective technique for non-invasive colon cancer screening that can be an alternative to optical colonoscopy (OC). However, current CTC examinations require pre-examination cathartic bowel preparation, essentially identical to that required for OC. The perceived discomfort and inconvenience associated with the rigorous cathartic bowel preparation before a CTC examination has been identified as the main barrier to wide acceptance of colon screening. The main technical barrier in applying non-cathartic bowel preparation to CTC examination is the lack of an effective electronic cleansing (EC) scheme for subtraction of tagged fecal materials in CTC images, because the cleansing artifacts encountered in current EC methods are too severe to allow non-cathartic CTC images of diagnostic quality. Dual-energy CT (deCT) is a new imaging technique that allows materials differentiation based on CT attenuation values derived from two synchronous CT acquisitions at different energies. Non-cathartic dual-energy CTC (deCTC), i.e., applying deCT to non-cathartic CTC image acquisition, has the potential significantly to improve the quality of EC. In this project, we will develop an EC scheme for non-cathartic deCTC, denoted as dual-energy EC (deEC), in which patients will be examined with non-cathartic bowel preparation and imaged with a deCT scanner. After image acquisition, the proposed deEC scheme will effectively remove the residual fecal materials in the colon in CTC images by a set of novel image processing methods developed in a dual-energy context. The capability of material differentiation in deCTC provides a new dimension for obviating the major cleansing artifacts existing in current EC methods, and thus provides CTC images of diagnostic quality. For evaluation purposes, we will establish a non-cathartic DE-CTC database. The quality and performance of the proposed DE-EC scheme will be evaluated in a phantom study, a manual cleansing study, a computer-aided detection (CAD) of polyps study, and an observer study. This research is innovative in that the non-cathartic deCTC and the development of its deEC scheme have not yet been attempted. The successful development and validation of the proposed deEC scheme will provide radiologists with cleansed CTC images of diagnostic quality for detecting colon cancer, and it will release the patients from the main concern regarding colon screening. Such an deEC-aided non-cathartic deCTC examination could substantially increase the screening compliance, safety, and the capacity for colon cancer screening. Thus, the proposed research will substantially raise the screening rate and the early detection of colonic polyps and cancers.