MR colonography without colonic cleansing: a new strategy to improve patient acceptance.
OBJECTIVE
MR colonography permits accurate detection of colonic polyps larger than 8 mm. Patient acceptance remains limited because of the need for bowel cleansing. The aim of this study was to develop and assess a strategy obviating colonic cleansing by performing MR colonography in conjunction with fecal tagging based on the oral administration of barium.


METHODS
Six healthy volunteers and six patients with suspected colorectal tumors, undergoing conventional colonoscopy within 1 week of MR imaging, were included in this study. For fecal tagging, 200 mL of a barium-containing contrast agent was ingested with each of four principal meals preceding the examination. For MR colonography, the colon was filled with a barium and water mixture while gadobenate dimeglumine (0.2 mmol/kg) was injected IV.


RESULTS
The combination of fecal tagging and colonic filling with barium resulted in a homogeneously low signal throughout the colonic lumen in all 12 subjects. IV injection of gadolinium caused avid enhancement of the colonic wall. Similarly, lesions arising from the colonic wall enhanced avidly. In the six evaluated patients, MR colonography correctly identified two colonic carcinomas in two patients and one polyp in each of another two patients.


CONCLUSIONS
Fecal tagging obviates bowel cleansing and should, therefore, enhance patient acceptance for MR colonoscopy. Barium used as the tagging agent is promising because it is inexpensive, commercially available, and characterized by an excellent safety profile.
Lauenstein
T
T
Department of Diagnostic Radiology, University Hospital Essen, Hufelandstr. 55, D-45122 Essen, Germany.
Holtmann
G
G
Schoenfelder
D
D
Bosk
S
S
Ruehm
S G
SG
Debatin
J F
JF
D000328:Adult; D001466:Barium Sulfate; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010349:Patient Compliance; D011859:Radiography / Q000379:methods
D001466:Barium Sulfate