Strengths and weaknesses of dark-lumen MR colonography: clinical relevance of polyps smaller than 5 mm in diameter at the moment of their detection.
OBJECTIVE
To assess the clinical relevance of dark-lumen MR colonography (MRC) for the detection of colorectal lesions using conventional colonoscopy (CC) and histopathologic examinations as reference standard.


METHODS
A total of 72 patients underwent MRC and CC. MRC was performed using a contrast-enhanced high spatial resolution T1 weighted 3D volumetric interpolated breathhold examination (VIBE)-sequence. All removed colorectal lesions were evaluated by an experienced pathologist.


RESULTS
CC confirmed 65 polyps less than 5 mm in diameter. Non of those lesions could be detected using MRC. Just two (4%) of the 49 removed lesions smaller than 5 mm showed signs of dysplasia. Additionally, CC confirmed 25 polyps between 6-15 mm in diameter (MRC 22). All those 25 lesions were removed in CC. Only four (16%) of those polyps showed signs of dysplasia and malignancy (11, 13, 13 and 15 mm).


CONCLUSIONS
Dark-lumen MRC failed to detect all polyps smaller than 5 mm in diameter which are generally not clinically relevant at the moment of their detection and thus can be kept under surveillance. However, MRC as a non-invasive imaging modality is a promising alternative to CC in the detection of clinically relevant polyps larger than 5 mm in diameter.
Ajaj
Waleed
W
Medical Center, University Hamburg-Eppendorf, Hamburg, Germany. ajaj@uke.uni-hamburg.de
Ruehm
Stefan G
SG
Gerken
Guido
G
Goyen
Mathias
M
D000328:Adult; D000368:Aged; D003110:Colonic Neoplasms / Q000175:diagnosis*; D003111:Colonic Polyps / Q000175:diagnosis*; D003113:Colonoscopy; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives*; D008875:Middle Aged; D009942:Organometallic Compounds; D011230:Precancerous Conditions / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine