Detection of colonic masses with MR colonography

Magnetic resonance colonography based on magnetic resonance imaging is a relatively new diagnostic modality for diagnosing colon pathology. The aim of this study was to evaluate its performance in detecting colorectal masses.

Thirty-three patients (20 male, 13 female; age range 28-85 years; mean age 78.7) suspected of having colonic lesions because of rectal bleeding, positive fecal occult blood test results or altered bowel habits underwent magnetic resonance colonography and subsequent conventional colonoscopy. All patients underwent standard bowel preparation 24 h before magnetic resonance colonography. Patients were placed in a supine position on the magnetic resonance table. After placement of a rectal tube, the colon was filled with of a mixture of 1000-1800 ml 0.9% NaCl solution and 15-20 ml 0.5 mmol/L gadopentetate dimeglumine solution. Once colonic distension was achieved, 3D GRE magnetic resonance colonography and complementary Magnetic resonance images were taken in all cases.

Sensitivity of magnetic resonance colonography for colorectal masses was 90% and specificity was 100%. Percentage of correct diagnosis of magnetic resonance colonography was 94.3%. Magnetic resonance colonography was well tolerated without sedation or analgesia.

Magnetic resonance colonography is a new technique for imaging of the colon. Magnetic resonance colonography has potential advantages of multiplanar capabilities and of being a less-invasive imaging technique; it can be implemented in daily practice and has a role in accurately staging colorectal cancers. In symptomatic patients, this new technique shows promising results for the detection and imaging of colorectal masses.