What is the small sac located between the junctional fold and the neck of the gallbladder called?

Hartmann's pouch refers to the small sac that can be found between the junctional fold of the gallbladder and its neck. This anatomical structure is significant because it can sometimes harbor gallstones, which may not be visible in other areas of the gallbladder. Hartmann's pouch occurs due to the normal anatomical variant in the shape and positioning of the gallbladder, particularly where the gallbladder neck meets the body. Understanding this is important in the context of diagnostic ultrasound, as it aids in recognizing potential pathological conditions, such as cholecystitis or gallstone disease, which may originate from this area. The identification of Hartmann's pouch can even influence the choice of surgical interventions if surgery is required.