MR imaging for the preoperative planning of sphincter-saving surgery for tumors of the lower third of the rectum: Use of intravenous and endorectal contrast materials
M. Urban et al., MR imaging for the preoperative planning of sphincter-saving surgery for tumors of the lower third of the rectum: Use of intravenous and endorectal contrast materials, RADIOLOGY, 214(2), 2000, pp. 503-508
Citations number
27
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging","Medical Research Diagnosis & Treatment
PURPOSE: To evaluate the value of magnetic resonance (MR) imaging with a fl
exible surface coil in predicting the resectability of tumors in the lower
rectum and the feasibility of sphincteral salvage.
MATERIALS AND METHODS: In a prospective study, 61 patients with histologica
lly proved primary adenocarcincma of the lower or middle third of the rectu
m (<12 cm from the pectinate line) were examined at double-contrast-materia
l-enhanced MR imaging with a circular polarized flexible surface coil.
RESULTS: Assessment of anal sphincteral infiltration at MR imaging was exce
llent, with a specificity of 98% and a sensitivity of 100%. In the determin
ation of tumor infiltration into adjacent organs (T4), the specificity was
100%, and the sensitivity was 90%, with surgical and histologic findings as
the standards. While MR imaging showed negative nodes in 40 patients (stag
e NO at MR imaging), histologic examination showed negative nodes in 27 pat
ients and positive nodes in 34. At MR imaging, sensitivity was 68%, and spe
cificity was 24%.
CONCLUSION: While preoperative staging at MR imaging according to the TNM s
ystem still has limited value and accuracy, MR imaging provides the surgeon
with valuable information regarding the presence of sphincteral invasion a
nd the surrounding structures in patients with cancers in the lower third o
f the rectum.