Colonic masses: detection with MR colonography.
OBJECTIVE
To assess magnetic resonance (MR) colonography as a method for detection of colorectal masses, with conventional colonoscopy as the reference standard.


METHODS
MR colonography was performed in 132 patients referred for colonoscopy because of the possible presence of a mass. After rectal filling with a gadopentetate dimeglumine and water enema, T1-weighted three-dimensional gradient-echo MR studies were acquired with the patient in the prone and supine positions. Water-sensitive single-shot fast spin-echo MR images were also obtained. Surface-rendered virtual endoscopic endoluminal views, orthogonal sections in three planes, and water-sensitive MR images were interactively assessed for presence of colorectal masses by two radiologists.


RESULTS
MR colonography was well tolerated without sedation or analgesia. MR image quality was sufficient for diagnosis in 127 (96%) patients. Most small (</=5-mm-diameter) masses were overlooked at MR colonography, but 19 of 31 6-10-mm lesions and 26 of 27 large (>10-mm) lesions were correctly identified. For these large masses, MR colonography had a sensitivity of 93%, specificity of 99%, positive predictive value of 92%, and negative predictive value of 98% for detection of masses.


CONCLUSIONS
MR colonography is a promising modality for help in detecting colorectal mass lesions larger than 10 mm in diameter.
Institute of Diagnostic Radiology, University Hospital Zurich, Switzerland.
W
W
Luboldt
P
P
Bauerfeind
S
S
Wildermuth
B
B
Marincek
M
M
Fried
J F
JF
Debatin
D000285:Administration, Rectal; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003110:Colonic Neoplasms / Q000175:diagnosis*; D003113:Colonoscopy; D003287:Contrast Media / Q000008:administration & dosage; D004733:Enema; D005260:Female; D019786:Gadolinium DTPA / Q000008:administration & dosage; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D016684:Prone Position; D012680:Sensitivity and Specificity; D016683:Supine Position; D014584:User-Computer Interface; D014867:Water
D003287:Contrast Media; D014867:Water; D019786:Gadolinium DTPA