The spectrum of cloacal malformations: how to differentiate each entity prenatally with fetal MRI.

The term cloacal malformation is commonly used to describe the classic cloacal malformation where there is a single common urogenital and intestinal channel located at the expected site of the urethra. There is, however, a spectrum of cloacal abnormalities that differ from this classic type and are less well discussed in the radiologic and surgical literature. The aim of this pictorial essay is to familiarize radiologists with the anatomy, appropriate terminology and key prenatal imaging findings that differentiate the six entities that constitute the spectrum of cloacal abnormalities.