Acute cholecystitis (AC), defined as inflammation of the gallbladder, is mainly caused by gallstones. Over 90% of AC results from obstruction of the cystic duct by stones or sludge, which subsequently increases the intraluminal pressure within the gallbladder and, in conjunction with the presence of bile supersaturated with cholesterol, activates an acute inflammatory cascade. Clinical features play an important role in the diagnosis of AC. The Tokyo Guidelines 2018 for acute cholecystitis designates the presence of local inflammatory signs and systemic inflammatory signs for a suspected diagnosis. It requires confirmation by radiological imaging along with these two factors for a definitive diagnosis. Thanks to less invasiveness, easy availability, ease of use, and cost-effectiveness, ultrasound (US) is usually accepted as the first choice in suspicious AC patients. A meta-analysis comparing methods of diagnosis for AC reported that the US has 81% of sensitivity and 83% of specificity. Abdominal computed tomography is recommended for diagnosing emphysematous or gangrenous cholecystitis. Meanwhile, acute acalculous cholecystitis (AAC) is a life-threatening disease mainly in severely ill patients. It usually affects the patients hospitalized for multiple trauma, burns, cardiopulmonary bypass surgery, long-term total parenteral nutrition or sepsis. The diagnosis of AAC is quite challenging and requires a high index of suspicion. Currently, cholecystectomy is the treatment of choice for AC, although the optimal time for surgery is still controversial. Due to high morbidity and mortality in high surgical risk groups, percutaneous gallbladder drainage can be a safe and feasible alternative to cholecystectomy, particularly for patients unfit for the surgery.

서 론
본 론
    1. 급성 결석성 담낭염(acute calculous cholecystitis
    2. 급성무결석담낭염(acute acalculous cholecystitis,AAC)
결 론
요 약
REFERENCES

• 김국현(영남대학교 의과대학 내과학교실) | Kook Hyun Kim (Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Korea)