Colorectal neoplasm: magnetic resonance colonography with fat enema-initial clinical experience.
OBJECTIVE
To assess Magnetic resonance colonography with fat enema as a method for detection of colorectal neoplasm.


METHODS
Consecutive twenty-two patients underwent MR colonography with fat enema before colonoscopy. T1-weighted three-dimensional fast spoiled gradient-echo with inversion recovery sequence was acquired with the patient in the supine position before and 75 s after Gadopentetate Dimelumine administration. Where by, pre and post MR coronal images were obtained with a single breath hold for about 20 s to cover the entire colon. The quality of MR colonographs and patients' tolerance to fat contrast medium was investigated. Colorectal neoplasms identified by MR colonography were compared with those identified on colonoscopy and sensitivity of detecting the lesions was calculated accordingly.


RESULTS
MR colonography with fat enema was well tolerated without sedation and analgesia. 120 out of 132 (90.9%) colonic segments were well distended and only 1 (0.8%) colonic segment was poor distension. After contrast enhancement scan, mean contrast-to-noise ratio (CNR) value between the normal colonic wall and lumen was 18.5 +/- 2.9 while mean CNR value between colorectal neoplasm and lumen was 20.2 +/- 3.1. By Magnetic resonance colonography, 26 of 35 neoplasms (sensitivity 74.3%) were detected. However, sensitivity of MRC was 95.5% (21 of 22) for neoplasm larger than 10 mm and 55.6% (5 of 9) for 5-10 mm neoplasm.


CONCLUSIONS
MR colonography with fat enema and T1-weighted three-dimensional fast spoiled gradient-echo with inversion recovery sequence is feasible in detecting colorectal neoplasm larger than 10 mm.
Zhang
Shuai
S
Department of Radiology, Fudan University Cancer Hospital Shanghai 200032, China.
Peng
Jun-Wei
JW
Shi
Qiang-Ying
QY
Tang
Feng
F
Zhong
Min-Guo
MG
D000368:Aged; D000369:Aged, 80 and over; D003106:Colon / Q000473:pathology; D003113:Colonoscopy / Q000379:methods*; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D004733:Enema / Q000379:methods*; D005223:Fats / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity
D005223:Fats