title: Information-Preserving Pseudo-Enhancement Correction for Non-Cathartic Low-Dose Dual-Energy CT Colonography.
abstract: In CT colonography (CTC), orally administered positive-contrast fecal-tagging agents can cause artificial elevation of the observed radiodensity of adjacent soft tissue. Such pseudo-enhancement makes it challenging to differentiate polyps and folds reliably from tagged materials, and it is also present in dual-energy CTC (DE-CTC). We developed a method that corrects for pseudo-enhancement on DE-CTC images without distorting the dual-energy information contained in the data. A pilot study was performed to evaluate the effect of the method visually and quantitatively by use of clinical non-cathartic low-dose DE-CTC data from 10 patients including 13 polyps covered partially or completely by iodine-based fecal tagging. The results indicate that the proposed method can be used to reduce the pseudo-enhancement distortion of DE-CTC images without losing material-specific dual-energy information. The method has potential application in improving the accuracy of automated image-processing applications, such as computer-aided detection and virtual bowel cleansing in CTC.
authors.affiliation: 3D Imaging Research, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 25 New Chardon Street, Suite 400C, Boston, MA 02114, USA.
authors.forename: Janne J
authors.initials: JJ
authors.lastname: Näppi
authors.affiliation: Institute for Cancer Research and Treatment, Candiolo Str. Prov. 142, 10060 Turin, Italy.
authors.forename: Rie
authors.initials: R
authors.lastname: Tachibana
authors.forename: Daniele
authors.initials: D
authors.lastname: Regge
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yoshida
keywords: CT colonography; Dual-energy CT; Pseudo-enhancement; Virtual colonoscopy