Renal agenesis: how sure are you?

Abstract

Objective: The aims of this study were: to review pitfalls in the sonographic diagnosis of renal agenesis; to demonstrate the role of pre-natal magnetic resonance imaging (MRI) in establishing the diagnosis; and to review potential pitfalls in the interpretation of pre-natal MRI. Methods: We conducted a retrospective review of a series of cases in which pre-natal MRI was performed to evaluate possible renal agenesis. Results: MRI showed renal agenesis in three cases of oligo/anhydramnios where kidneys were thought to be present on ultrasound. MRI confirmed the presence of kidneys and showed abnormal placenta in another fetus with anyhdramnios thought sonographically to have renal agenesis. All ultrasound scans were performed by perinatologists experienced in pre-natal imaging. Conclusions: Sonographic diagnosis of renal agenesis can be compromised by maternal body habitus and anyhdramnios. In selected cases, pre-natal MRI is a useful adjunct to confirm the diagnosis prior to offering termination of pregnancy.