ECE Deparmental Seminar 

Computed Tomography Colonography (Virtual Colonoscopy): What we have done, and what challenges remain?

Jerome Zhengrong Liang, PhD

Department of Radiology, Stony Brook University

Friday, 2/2/18, 11:00am
Light Engineering 250

Abstract: Colorectal cancer (CRC) remains the 2nd leading cause of cancer-related death. Different from many other cancers, CRC can be prevented by detection and removal of its precursor lesion, the adenomatous polyps. CRC is amenable to screening because of the long time interval (~10 years) of adenoma-carcinoma sequence. For example, it takes >2 years for an adenomatous polyp to grow to 5mm size with far less than 1% cancer risk, an extra 3 or more years to grow to 10mm size with cancer risk approaching 1%, and another 5 or more years grow to 20mm size and 10% cancer risk. Therefore, a safe, convenient, cost-effective screening method is clinically desired to screen the large population of age 50 and older at an adequate time interval.

Virtual colonoscopy using computed tomography (CT) technologies, called CT colonography (CTC), has been under development in the past two decades and has achieved comparable performance to the clinical optical colonoscopy (OC) for detection of polyps of size 8mm and larger. This presentation will report our recent research progress in advancing the CTC detection capability to smaller polyps down to 5mm and flat polyps as well.

With the good detection rate of CTC, we expect to detect a large number of small polyps of size from 5mm to 10mm. A significant portion of the polyps in this size range are hyperplastic, which is harmless and resecting them gains nothing but getting risks of sedation, perforation, bleeding, etc. Therefore, differentiating the hyperplastic from adenomatous polyps in the detected polyp pool is clinically desirable. CTC provides the fully three-dimensional (3D) imaging data, which contains very rich information for the differentiation or diagnosis task and offers a superior opportunity that OC may not have. This presentation will report our recent research progress in advancing the current CTC detection-only paradigm to a new level of not only detection but also diagnosis of the detected polyps for personnel-managed healthcare.