Endorectal ultrasound and magnetic resonance imaging (MRI) scan in rectal cancer: a comparative study

Endorectal ultrasound was compared with magnetic resonance imaging (MRI) in the preoperative staging for patients with Rectal Cancer. Diagnostic accuracy was assessed with regards to the factors that might influence the risk of local relapse such as T, N and CRM (circumferential resection margin).From January 2006 to April 2010, 64 patients with rectal cancer were studied preoperatively either by means of MRI scan of the pelvis or endorectal ultrasound scan in order to assess the intramural extension. For 30 out of 64 patients both methods were used (comparing instrumental with histopathological data) while for 34 patients over 64 only ultrasound scan was used.Endorectal ultrasound resulted to be more reliable in defining the T (parietal infiltration of the tumor) whereas MRI better defined CRM.Both methods are reliable and complementary enabling an accurate staging of patients with rectal cancer.