A comparison of computed tomography and endorectal ultrasound in staging rectal cancer.

Endorectal ultrasound was used prospectively to stage 85 patients with rectal cancer. All patients had surgical exploration and histological analysis. Demonstration of tumour, extension into perirectal fat and lymph node involvement were evaluated. Eighty-one tumours were successfully imaged by endorectal ultrasound. The results suggest that: endorectal ultrasound is more accurate than CT in detecting the site of tumour; endorectal ultrasound is more accurate than CT in detecting perirectal fat infiltration; endorectal ultrasound is slightly more accurate than CT in detecting level II lymph node involvement.