Abdominal hereditary angio-oedema caught on magnetic resonance imaging

A 17-year-old woman presented with a 3-year history of recurrent, severe abdominal pain with spontaneous resolution within a few days. An ultrasound revealed nothing more than free fluid within the pelvis. An MRI of the small bowel was done within 24 hours of abdominal pain onset, which revealed extensive submucosal oedema associated with moderate volume ascites. A repeat MRI of the small bowel after 72 hours showed near-complete resolution of these changes. Checking C1 inhibitor levels confirmed a diagnosis of hereditary angio-oedema with an abdominal presentation. This is a rare cause of recurrent abdominal pain and, to our knowledge, the first case in which MR images have been obtained during and after an acute attack.