Magnetic resonance imaging in suspected rectal cancer: determining tumor localization, stage, and sphincter-saving resectability at 3-Tesla-sustained high resolution.
OBJECTIVE
To assess image quality and overall accuracy of 3-Tesla (3T)-sustained high-resolution magnetic resonance (MR) imaging for diagnostic preoperative workup in suspected rectal carcinoma.


METHODS
Twenty-three patients with suspected rectal cancer underwent unenhanced and contrast-enhanced fat-suppressed pelvic high-resolution MR imaging using a four-channel phased-array pelvic coil at 3T. Image quality, tumor stage, distance from the anorectal margin, and sphincter-saving resectability were prospectively assessed by two blinded readers. The results were correlated with clinical, surgical, and histopathologic findings.


RESULTS
In all 23 patients, MR images were of diagnostic quality, and malignancy was correctly identified in 21 patients. The accuracy for determining sphincter-saving resectability was 100% (19/19). T stage and N stage were correctly diagnosed in 95% and 91%, respectively. MRI allowed correct identification of tumor extension and its relation to surgically relevant pelvic structures including the anorectal margin and mesorectal fascia. Transverse T2-weighted fast spin-echo images compared superiorly to all other sequences for the diagnosis of mesorectal infiltration and lymph node involvement. Moreover, transverse fat-suppressed contrast-enhanced T1-weighted images were valuable for identifying tumor infiltration, while sagittal sections were useful for the detection of longitudinal tumor extension.


CONCLUSIONS
MR imaging with phased-array receiver coils at 3T facilitated both visualization of different pathologic conditions of the rectum and accurate determination of tumor stage in rectal carcinomas. Thus, this noninvasive diagnostic approach appeared highly suitable for the assessment of patients with suspected rectal carcinoma.
Winter
L
L
Department of Radiology, Charite Medical University Center, Campus Virchow Clinic, Berlin, Germany.
Bruhn
H
H
Langrehr
J
J
Neuhaus
P
P
Felix
R
R
Hänninen
Lopez E
LE
D000230:Adenocarcinoma / Q000175:diagnosis / Q000473:pathology / Q000601:surgery; D018256:Adenomatous Polyps / Q000175:diagnosis / Q000473:pathology / Q000601:surgery; D000368:Aged; D001003:Anal Canal / Q000473:pathology / Q000601:surgery*; D003287:Contrast Media; D003586:Cytomegalovirus Infections / Q000175:diagnosis; D005205:Fascia / Q000473:pathology; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011300:Preoperative Care; D011349:Proctitis / Q000175:diagnosis / Q000821:virology; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D012007:Rectum / Q000473:pathology; D012680:Sensitivity and Specificity
D003287:Contrast Media