MR colonography with barium-based fecal tagging: initial clinical experience.
OBJECTIVE
To assess a strategy for fecal tagging with barium sulfate as an inexpensive tagging agent in conjunction with magnetic resonance (MR) colonography in patients suspected of having colorectal lesions.


METHODS
Twenty-four patients suspected of having colonic lesions because of rectal bleeding, positive fecal occult blood test results, or altered bowel habits underwent MR colonography and subsequent conventional colonoscopy. A 200-mL dose of a barium sulfate-containing contrast agent was ingested with each of four low-fiber meals, beginning 36 hours before the examination. For MR colonography, the colon was filled with tap water. Gadobenate dimeglumine was injected intravenously. Images were acquired 75 seconds after gadobenate dimeglumine administration by using only a T1-weighted three-dimensional gradient-echo sequence. Images were reviewed by two radiologists blinded to conventional colonoscopic data. By using colonoscopy as the reference standard, sensitivity and specificity of MR colonography were determined for detecting colorectal masses.


RESULTS
On the basis of MR colonography, 15 polyps of 5-20 mm and 10 carcinomas were detected and later confirmed with conventional colonoscopy. Conventional colonoscopy depicted three additional lesions less than 8 mm in diameter. Thus, sensitivity of MR colonography was 89.3% (25 of 28) for lesions and 91.7% (22 of 24) for patients.


CONCLUSIONS
Barium-tagged MR colonography obviates bowel cleansing and depicts all lesions exceeding 8 mm in diameter.
Lauenstein
Thomas C
TC
Department of Diagnostic Radiology, University Hospital Essen, Hufelandstrasse 55, D-45122 Essen, Germany.
Goehde
Susanne C
SC
Ruehm
Stefan G
SG
Holtmann
Gerald
G
Debatin
Jörg F
JF
D000328:Adult; D000368:Aged; D001466:Barium Sulfate; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D003287:Contrast Media; D005243:Feces; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011859:Radiography
D003287:Contrast Media; D001466:Barium Sulfate