title: Electronic cleansing for 24-h limited bowel preparation CT colonography using principal curvature flow.
abstract: CT colonography (CTC) is one of the recommended methods for colorectal cancer screening. The subject's preparation is one of the most burdensome aspects of CTC with a cathartic bowel preparation. Tagging of the bowel content with an oral contrast medium facilitates CTC with limited bowel preparation. Unfortunately, such preparations adversely affect the 3-D image quality. Thus far, data acquired after very limited bowel preparation were evaluated with a 2-D reading strategy only. Existing cleansing algorithms do not work sufficiently well to allow a primary 3-D reading strategy. We developed an electronic cleansing algorithm, aimed to realize optimal 3-D image quality for low-dose CTC with 24-h limited bowel preparation. The method employs a principal curvature flow algorithm to remove heterogeneities within poorly tagged fecal residue. In addition, a pattern recognition-based approach is used to prevent polyp-like protrusions on the colon surface from being removed by the method. Two experts independently evaluated 40 CTC cases by means of a primary 2-D approach without involvement of electronic cleansing as well as by a primary 3-D method after electronic cleansing. The data contained four variations of 24-h limited bowel preparation and was based on a low radiation dose scanning protocol. The sensitivity for lesions ≥ 6 mm was significantly higher for the primary 3-D reading strategy (84%) than for the primary 2-D reading strategy (68%) (p = 0.031). The reading time was increased from 5:39 min (2-D) to 7:09 min (3-D) (p = 0.005); the readers' confidence was reduced from 2.3 (2-D) to 2.1 (3-D) ( p = 0.013) on a three-point Likert scale. Polyp conspicuity for cleansed submerged lesions was similar to not submerged lesions (p = 0.06). To our knowledge, this study is the first to describe and clinically validate an electronic cleansing algorithm that facilitates low-dose CTC with 24-h limited bowel preparation.
authors.forename: Vincent F
authors.initials: VF
authors.lastname: van Ravesteijn
authors.forename: Thierry N
authors.initials: TN
authors.lastname: Boellaard
authors.forename: Marije P
authors.initials: MP
authors.lastname: van der Paardt
authors.forename: Iwo W O
authors.initials: IW
authors.lastname: Serlie
authors.forename: Margriet C
authors.initials: MC
authors.lastname: de Haan
authors.forename: Jaap
authors.initials: J
authors.lastname: Stoker
authors.forename: Lucas J
authors.initials: LJ
authors.lastname: van Vliet
authors.forename: Frans M
authors.initials: FM
authors.lastname: Vos
mesh_terms: D000465:Algorithms; D003106:Colon / Q000033:anatomy & histology; D023881:Colonography, Computed Tomographic / Q000379:methods*; D005243:Feces; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results