Acalculous Cholecystitis: Inflammation of the GALLBLADDER wall in the absence of GALLSTONES.Cholecystitis: Inflammation of the GALLBLADDER; generally caused by impairment of BILE flow, GALLSTONES in the BILIARY TRACT, infections, or other diseases.Cholecystitis, Acute: Acute inflammation of the GALLBLADDER wall. It is characterized by the presence of ABDOMINAL PAIN; FEVER; and LEUKOCYTOSIS. Gallstone obstruction of the CYSTIC DUCT is present in approximately 90% of the cases.Gallbladder: A storage reservoir for BILE secretion. Gallbladder allows the delivery of bile acids at a high concentration and in a controlled manner, via the CYSTIC DUCT to the DUODENUM, for degradation of dietary lipid.Technetium Tc 99m Disofenin: A radiopharmaceutical used extensively in cholescintigraphy for the evaluation of hepatobiliary diseases. (From Int Jrnl Rad Appl Inst 1992;43(9):1061-4)Gallbladder Diseases: Diseases of the GALLBLADDER. They generally involve the impairment of BILE flow, GALLSTONES in the BILIARY TRACT, infections, neoplasms, or other diseases.Cholecystectomy: Surgical removal of the GALLBLADDER.Imino AcidsBiliary Dyskinesia: A motility disorder characterized by biliary COLIC, absence of GALLSTONES, and an abnormal GALLBLADDER ejection fraction. It is caused by gallbladder dyskinesia and/or SPHINCTER OF ODDI DYSFUNCTION.Cholecystostomy: Establishment of an opening into the gallbladder either for drainage or surgical communication with another part of the digestive tract, usually the duodenum or jejunum.Acute Disease: Disease having a short and relatively severe course.Cholecystectomy, Laparoscopic: Excision of the gallbladder through an abdominal incision using a laparoscope.Emphysematous Cholecystitis: A variant of acute cholecystitis with inflammation of the GALLBLADDER that is characterized by the pockets of gas in the gallbladder wall. It is due to secondary infection caused by gas-forming organisms, and has a high risk of perforation.Gallbladder Emptying: A process whereby bile is delivered from the gallbladder into the duodenum. The emptying is caused by both contraction of the gallbladder and relaxation of the sphincter mechanism at the choledochal terminus.Gangrene: Death and putrefaction of tissue usually due to a loss of blood supply.Cholelithiasis: Presence or formation of GALLSTONES in the BILIARY TRACT, usually in the gallbladder (CHOLECYSTOLITHIASIS) or the common bile duct (CHOLEDOCHOLITHIASIS).