Accuracy of staging rectal tumors with contrast-enhanced transrectal MR imaging.
OBJECTIVE
Our objective was to evaluate the accuracy of contrast-enhanced transrectal MR imaging in staging rectal adenoma and carcinoma by correlating with histopathologic findings.


METHODS
Thirty-five patients underwent transrectal MR imaging on a 1.5-T superconducting unit using unenhanced T1-weighted and T2-weighted spin-echo and turbo spin-echo sequences, a dynamic gadopentetate dimeglumine-enhanced turbo fast low-angle shot sequence, and enhanced T1-weighted spin-echo sequences. For all patients, histopathologic correlation was available from biopsy (n = 15) or surgical resection (n = 20). Two radiologists unaware of each other's interpretations of the scans interpreted each case from which we evaluated qualitative and quantitative data.


RESULTS
Rectal adenomas (n = 15) were identified when imaging revealed an intact muscularis mucosae, a homogeneous internal structure, and high contrast enhancement of the lesion. Carcinomas staged as T1 by TNM criteria (n = 6) were best revealed by dynamic turbo fast low-angle shot sequences, in which an intact muscularis propria could be seen. Visualization of enhancing tumor tissue in the muscularis propria indicated T2 carcinoma (n = 5). All T3 (n = 5) and T4 (n = 4) carcinomas were correctly staged with dynamic and static MR imaging. The stage revealed by MR imaging correlated well with histologic staging results in 89% (observer 1) and 86% (observer 2) of interpretations. However, when interpreting MR imaging, observers tended to overstage and never understaged.


CONCLUSIONS
Transrectal surface-coil MR imaging provided reliable information in staging patients before surgery and in evaluating rectal adenoma and carcinoma.
Vogl
T J
TJ
Department of Radiology, Virchow Hospital, Humboldt University of Berlin, Germany.
Pegios
W
W
Mack
M G
MG
Hünerbein
M
M
Hintze
R
R
Adler
A
A
Lobbeck
H
H
Hammerstingl
R
R
Wust
P
P
Schlag
P
P
Felix
R
R
D018253:Adenoma, Villous / Q000473:pathology*; D002277:Carcinoma / Q000473:pathology*; D003287:Contrast Media; D004338:Drug Combinations; D005260:Female; D005682:Gadolinium; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008536:Meglumine; D008875:Middle Aged; D009130:Muscle, Smooth / Q000473:pathology; D009367:Neoplasm Staging; D009942:Organometallic Compounds; D004369:Pentetic Acid / Q000031:analogs & derivatives; D012004:Rectal Neoplasms / Q000473:pathology*; D012007:Rectum / Q000473:pathology*
D003287:Contrast Media; D004338:Drug Combinations; D009942:Organometallic Compounds; D008536:Meglumine; D004369:Pentetic Acid; D005682:Gadolinium; D019786:Gadolinium DTPA