Benign anorectal disease comprises a broad group of processes with very diverse origins; these processes may be congenital or acquired as well as inflammatory or tumor related. However, benign anorectal disease has received less attention in the scientific literature than malignant disease. We present an image-based review of the most common benign diseases of the anus and rectum. In this first part, we review the anatomy of the region and provide a brief description of the peculiarities of the high resolution protocol that we use with 3.0 T MRI. We go on to describe the most common benign anorectal tumors and developmental cystic lesions, together with their differential diagnoses, as well as congenital and acquired anomalies of the anorectal sphincter complex.
Keywords: Anal canal; Canal anal; Lower gastrointestinal tract; Magnetic resonance imaging; Recto; Rectum; Resonancia magnética; Tracto gastrointestinal inferior.
Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.