[Ultrasonic features of congenital anomalies of the gallbladder].

Congenital anomalies of the gallbladder (GB) correspond to the ultimate manifestation of the wide range of anatomical variations that may affect the GB. Anomalies may be numerical: duplication, accessory GB, and, rarely, agenesis. Anomalies of position are more common: ectopic GB, floating or wandering GB. Morphological anomalies (septations) are the most common GB anomalies. Most of these anomalies may result in pitfalls at US imaging.