Pregnant patients suspected of having acute appendicitis: effect of MR imaging on negative laparotomy rate and appendiceal perforation rate.

Purpose: To investigate the effect of magnetic resonance (MR) imaging on the negative laparotomy rate (NLR) and the perforation rate (PR) in pregnant patients suspected of having acute appendicitis (AA) and to assess the need for computed tomography (CT) in this setting.

Materials And Methods: The data of 148 consecutive pregnant patients (mean age, 29 years; age range, 15-42 years; mean gestational age, 20 weeks; gestational age range, 4-37 weeks) who were clinically suspected of having AA and examined with MR imaging between March 2002 and August 2007 were retrospectively analyzed in an institutional review board-approved HIPAA-compliant protocol. One hundred forty patients underwent ultrasonography (US) before MR imaging.