Imaging evaluation of gallbladder wall thickening

Gallbladder is a pear shaped organ lying in the inferior margin of the liver, between the right and left lobes of liver. The gallbladder is divided into the fundus, body, and neck; the fundus is the most anterior and often inferior segment. In the region of gallbladder neck, there may be an infundibulum, called Hartmann's pouch, which is a common location for impaction of gallstones. The interlobar fissure, the third structure separating the two hepatic lobes, extends from the origin of the right portal vein to the gallbladder fossa. This fissure has been seen in up to 70% of hepatic ultrasound studies and may also be used as a landmark for the gallbladder fossa. In the gallbladder wall, the muscle layer is muscularis propria and there is no muscularis mucosa present. In the cystic duct and common bile duct, only an attenuated and incomplete muscle layer of muscularis mucosae is present; because there is no muscularis propria, so their contractile function is limited. Differentiating these anatomical muscle structures may be important for the pathologic staging of carcinoma in these organs.