Effect of using endorectal coil in preoperative staging of rectal carcinomas by pelvic MR imaging.
OBJECTIVE
To assess the accuracy of magnetic resonance imaging with pelvic phased-array and endorectal coils prospectively, and evaluate if endorectal coil provides any additional information to high resolution pelvic MR imaging in rectal carcinoma staging.


METHODS
Preoperative MRI of 25 patients with rectal carcinoma was performed with pelvic phased-array coil alone, and with both phased-array coil and endorectal coil placed. Staging was made by evaluating images obtained by using both coils prospectively, and correlated with histopathologic staging. The images were then assessed separately, and compared to each other retrospectively.


RESULTS
Two and 3 of the 5 histopathologically proved T1 tumors were staged correctly on MRI with pelvic phased-array coil alone and after the endorectal coil placement, respectively. Histopathologically identified five T2 tumors were staged correctly as T2 in 4 of the cases, 1 was understaged and 10 of 14 patients who had T3 tumor were staged as T3, 4 of them were understaged as T2 on both techniques. Specificity, sensitivity and accuracy rates for staging of T3 tumors were found as 71%, 100% and 84%, respectively, for each technique. Sensitivity and positive predictive value of N staging were both 88% on both techniques.


CONCLUSIONS
Pelvic MR imaging after the placement of endorectal coil in addition to the phase-array coil was not superior to the imaging with phased-array coil alone in T staging of rectal carcinomas and the latter achieved better visualization of the lymph nodes by means of larger field of view.
Donmez
Fuldem Yildirim
FY
Department of Radiology, Baskent University, Faculty of Medicine, 06490 Bahcelievler, Ankara, Turkey. fuldemyildirim@yahoo.com
Tunaci
Mehtap
M
Yekeler
Ensar
E
Balik
Emre
E
Tunaci
Atadan
A
Acunas
Gulden
G
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000473:pathology*; D012004:Rectal Neoplasms / Q000175:diagnosis*; D012007:Rectum / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity