Preoperative magnetic resonance staging of rectal cancer with an endorectal coil and dynamic gadolinium enhancement.
BACKGROUND
The aim of the study was to assess the value of endorectal coil magnetic resonance imaging (MRI) with gadolinium enhancement in the preoperative staging of rectal cancer.


METHODS
In addition to standard evaluation, patients with rectal lesions were assessed by MRI obtained with a pelvic phased-array coil in combination with an endorectal coil.


RESULTS
The study group comprised 29 patients with rectal cancer staged with an endorectal coil who had surgery without preoperative adjuvant therapy. In addition to standard T1- and T2-weighted images, dynamic contrast-enhanced images were acquired in all patients. Considerable interobserver variation was noted, particularly for pathological tumour stage pT1 or pT2 (kappa = 0.36). Compared with pathological findings, endorectal MRI correctly staged nine patients, overstaged 16 and understaged four. Whilst lymph node metastases were accurately detected in 70 per cent of patients, the positive predictive value was only 58 per cent.


CONCLUSIONS
MR staging of rectal cancer with an endorectal coil and gadolinium enhancement is inaccurate for early tumours (stage T1 or T2) and is associated with a considerable degree of interobserver variation for individual scan sequences.
Drew
P J
PJ
Academic Surgical Unit, University of Hull, UK.
Farouk
R
R
Turnbull
L W
LW
Ward
S C
SC
Hartley
J E
JE
Monson
J R
JR
D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D009367:Neoplasm Staging / Q000379:methods* / Q000592:standards; D015588:Observer Variation; D011300:Preoperative Care; D012004:Rectal Neoplasms / Q000175:diagnosis*; D012680:Sensitivity and Specificity
D019786:Gadolinium DTPA