Measurement of Anal Sphincter Muscles: Endoanal US, Endoanal MR Imaging, or Phased-Array MR Imaging? A Study with Healthy Volunteers

Abstract

Endoanal US enables reliable measurement of only internal sphincter thickness, whereas both MR imaging methods enable reliable measurement of all sphincter components. Sphincter measurement with phased-array MR imaging is as reliable as that with endoanal MR imaging.