Objective: To evaluate the accuracy of preoperative magnetic resonance imaging (MRI) with water-bag in rectum in prediction of pathological staging of rectal cancer.
Methods: Clinical data of 19 patients with rectal carcinoma assessed by MRI with water-bag in rectum for tumour (T) and mesorectal nodal (N) staging were analyzed retrospectively. Preoperative MRI assessment was compared with postoperative histopathological findings.
Results: The tumors were correctly staged by MRI in 15 patients, understaged in 2 and overstaged in 2. The accuracy of T stage was 78.9% (15/19). Mesorectal node were correctly staged in 11 patients, overstaged in 2 and understaged in 6. The accuracy of node staging was 57.9% (11/19), sensitivity was 3/9, and specificity was 80%(8/10).
Conclusion: Preoperative MRI with water-bag in rectum can not provide correct predictive data on mesorectal node stage, but has certain value in the T staging of rectal carcinoma.