title: Dark-lumen MR colonography with fecal tagging: a comparison of water enema and air methods of colonic distension for detecting colonic neoplasms.
abstract: The purpose was to evaluate MR colonography (MRC) with barium fecal tagging in detecting colorectal pathology and to determine how air-based and water-based colonic distension influences MRC. We studied 83 patients with high risk of colonic neoplasms. All received oral barium sulfate for colonic preparation before unenhanced and enhanced T1-weighted gradient-echo MRC using either water (n=54) or air (n=29) for colonic distension. Fecal tagging, distension, and artifacts were recorded. All patients underwent conventional colonoscopy within 2 weeks of MRC; the techniques were compared for detection of malignant neoplasms and polyps >or=1 cm, 6-9 mm, and <or=5 mm. Fecal tagging was "good" in 76% of the colonic segments in water-distended patients and 46% of air-distended patients. The degree of distension was "good" in 90.7% of water-distended patients and 44% of air-distended patients. Severe artifacts were present in 15% air-distended patients and 0.3% of water-distended patients. Both water-distended and air-distended MRC detected all malignant neoplasms and polyps >or=1 cm, but more air-distended MRC were excluded for poor quality. MRC with fecal tagging is useful for detecting lesions >or=1 cm. Air distension was inferior to water distension in most aspects. Water-based colonic distension should be used for barium-tagging MRC.
authors.affiliation: Department of Radiology, Hospital Clinico of Barcelona, Villarroel, 170, 08036 Barcelona, Spain. srodrig@clinic.ub.es
authors.forename: Sonia
authors.initials: S
authors.lastname: Rodriguez Gomez
authors.forename: Mario
authors.initials: M
authors.lastname: Pagés Llinas
authors.forename: Antoni
authors.initials: A
authors.lastname: Castells Garangou
authors.forename: Carmen
authors.initials: C
authors.lastname: De Juan Garcia
authors.forename: Josep M
authors.initials: JM
authors.lastname: Bordas Alsina
authors.forename: Jordi
authors.initials: J
authors.lastname: Rimola Gibert
authors.forename: Juan R
authors.initials: JR
authors.lastname: Ayuso Colella
authors.forename: Carmen
authors.initials: C
authors.lastname: Ayuso Colella
mesh_terms: D000388:Air; D016477:Artifacts; D001466:Barium Sulfate; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D003287:Contrast Media; D004733:Enema / Q000379:methods*; D005243:Feces; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010349:Patient Compliance; D018709:Statistics, Nonparametric; D014867:Water
chemical_list: D003287:Contrast Media; D014867:Water; D001466:Barium Sulfate; C064925:gadodiamide; D019786:Gadolinium DTPA