Imaging of megacystis-microcolon-intestinal hypoperistalsis syndrome before, during, and after the neonatal period: a pictorial review

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS), also known as Berdon syndrome, is a rare genetic congenital disorder of impaired smooth muscle contractility, resulting in functional obstruction of the bladder and bowel. Historically associated with a poor prognosis, recent advances in the use of total parenteral nutrition (TPN), intestinal rehabilitation, and multi-visceral transplantation have led to improvements in survival in patients with MMIHS, with patients now living into the second decade of life. The radiologist plays a key role in the initial workup of these patients and is often the first to suggest the diagnosis. Furthermore, with patients living longer, the radiologist's role now includes the following: (1) identifying complications on follow-up imaging, such as distinguishing mechanical obstruction from dysmotility; (2) following findings of chronic kidney disease; and (3) recognizing cholestatic TPN-related liver disease. With expedient diagnosis and management, survival can be extended, and quality of life can be improved. This pictorial essay aims to demonstrate the spectrum of imaging findings in the prenatal stage, the neonatal period, and later childhood in confirmed cases. Clinical findings, management, and outcomes of MMIHS, as well as imaging features that differentiate MMIHS from similar conditions, will be discussed.