Rectal MRI is increasingly used in the context of multidisciplinary approach of rectal cancer for preoperative evaluation in order to select the most appropriate treatment for each patient. The aim of this study is to determine the diagnostic performance of preoperative rectal MRI in the study of rectal carcinoma regarding depth of infiltration in rectal wall and adjacent structures (T), local lymph node involvement (N), implication of mesorectal fascia and distance of lesion relative to anal margin.

Patients were prospectively followed after pelvic MRI for rectal cancer preoperative staging was performed with the following MRI sequences: · AXIAL OBLIQUE T2 (TSE): Thin slices (3 mm maximum) perpendicular to tumor, to accurately assess the tumor and its relationship to the rectal wall, mesorectal fascia and pelvic organs. · CORONAL T2 (TSE): Especially useful for patients with low rectal cancer to evaluate elevator muscles, sphincter complex, intersphincteric plane and relationship with rectal wall. · SAGITAL T2 (TSE): Mainly to calculate the distance to the...

29 patients have been studied, excluding 10 due to not meeting the conditions of the study. In the remaining 19 patients, rectal MRI has correctly calculated the distance to anal margin in 89.47% of cases. Involvement of mesorectal fascia was successfully set at 100%. As for nodal staging, was performed correctly in 73.68%. Regarding degree of depth infiltration in rectal wall and mesorectal adipose tissue T staging was successful in 52.63%. In our study diagnostic performance of MRI scanning in the preoperative assessment of rectal...

Rectal MRI is an excellent diagnostic tool for preoperative evaluation of rectal carcinoma, allowing the correct identification of tumor location, assessing surgical resection margins regarding involvement of mesorectal fascia and estimating properly nodal involvement. In our study, staging depth of infiltration was particularly successful in determining if the tumor infiltrates 5 mm beyond the mesorectal fat, crucial point for the prognosis and tumor treatment planning.

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