Acute cholecystitis is acute inflammation of the gallbladder, caused by gallstone obstruction of the cystic duct in 90-95% of cases (calculous cholecystitis). Following cystic duct obstruction, edema, inflammation, and ischemia develop in the gallbladder wall. If untreated, it may progress to gangrenous cholecystitis, perforation, and peritonitis. US is the primary diagnostic modality, and gallstones, wall thickening, pericholecystic fluid, and positive sonographic Murphy sign constitute the classic tetrad. Clinically presents with right upper quadrant pain, fever, and leukocytosis.
Age Range
30-80
Peak Age
55
Gender
Female predominant
Prevalence
Common
The pathophysiology of acute cholecystitis begins with gallstone obstruction of the cystic duct. Following obstruction, bile accumulates within the gallbladder, intraluminal pressure increases, and mucosal irritation develops. Prostaglandin release triggers the inflammatory cascade, causing wall edema and vascular congestion. This vascular congestion forms the basis for wall thickening (>3 mm) and hyperemic mucosa seen on US. Inflammation extends into pericholecystic fat tissue, producing pericholecystic fluid and edema — visible on CT as pericholecystic fat stranding. In advanced cases, vascular compromise leads to gangrenous changes and wall necrosis. Gangrenous cholecystitis may develop intramural gas (emphysematous cholecystitis) or wall defect (perforation). The positive sonographic Murphy sign reflects the localized pain response produced when transducer pressure compresses the inflamed gallbladder against the peritoneal surface.
Pain response arresting the patient's inspiration when the ultrasound transducer is pressed on the gallbladder fundus. A clinical-radiological finding with high specificity for acute cholecystitis. The advantage of US is real-time confirmation that the transducer is positioned exactly over the gallbladder. May be false negative in gangrenous cholecystitis due to necrosis of sensory nerve endings — this paradox between a negative Murphy sign and severe cholecystitis is clinically important.
Hyperechoic structure with posterior acoustic shadowing (gallstone) in the gallbladder lumen together with gallbladder wall thickening (>3 mm). Layered (striated) appearance may be seen due to wall edema.
Report Sentence
A hyperechoic structure with posterior acoustic shadowing (gallstone) is seen in the gallbladder lumen with wall thickening (… mm).
Anechoic fluid collection around the gallbladder. Pericholecystic fluid is the US indicator of inflammatory exudation and strongly supports the diagnosis of acute cholecystitis.
Report Sentence
Pericholecystic fluid is observed around the gallbladder.
Patient experiences pain that arrests inspiration when the transducer is pressed over the gallbladder fundus. Has high positive predictive value for acute cholecystitis (>90%).
Report Sentence
Positive sonographic Murphy sign is elicited with transducer pressure over the gallbladder fundus.
Increased vascularity in the gallbladder wall on Doppler US. Reflects inflammatory hyperemia and neovascularization.
Report Sentence
Increased wall vascularity is seen on Doppler US, consistent with inflammatory hyperemia.
Pericholecystic fat stranding, wall enhancement, and distension on contrast-enhanced CT. Pericholecystic fluid and transient hepatic enhancement at the liver-gallbladder interface may be seen.
Report Sentence
Pericholecystic fat stranding, wall enhancement, and distension are observed on CT, consistent with acute cholecystitis.
High signal in the gallbladder wall (edema) and pericholecystic fluid on T2-weighted MRI. The wall may show layered appearance. MRI is particularly superior in evaluating gangrenous cholecystitis complications.
Report Sentence
High signal consistent with edema in the gallbladder wall and pericholecystic fluid are seen on T2-weighted MRI.
Non-visualization of gallbladder on HIDA (hepatobiliary iminodiacetic acid) scintigraphy — the most reliable indicator of cystic duct obstruction. Considered diagnostic if the gallbladder does not fill at 60 minutes and remains unfilled after 30 minutes of morphine augmentation.
Report Sentence
The gallbladder is not visualized at 60 minutes on HIDA scintigraphy, supporting the diagnosis of acute cholecystitis with cystic duct obstruction.
Criteria
Acute cholecystitis due to gallstone (90-95%). Impacted stone in the cystic duct or stone in the gallbladder neck/infundibulum is observed.
Distinct Features
Wall thickening and positive Murphy sign together with gallstone or sludge on US. Localization of the stone in the cystic duct is important.
Criteria
Acute cholecystitis developing without gallstones (5-10%). Usually occurs in ICU patients, severe trauma, burns, prolonged TPN, HIV/AIDS patients.
Distinct Features
No gallstones on US but wall thickening, pericholecystic fluid, and distension are present. Higher complication rate (gangrene, perforation). HIDA scintigraphy is the gold standard for diagnosis.
Criteria
Complicated cholecystitis characterized by ischemia and necrosis of the gallbladder wall. Precursor to perforation.
Distinct Features
Irregular wall thickening, intraluminal membranes/debris on US, Murphy sign may paradoxically be negative. Wall enhancement defects, intramural gas, pericholecystic abscess on CT. Emergency surgical indication.
Distinguishing Feature
Wall thickening is present in chronic cholecystitis but pericholecystic fluid, positive Murphy sign, and acute clinical presentation are absent. The wall is fibrotic and smooth. Gallstones are frequently present.
Distinguishing Feature
Gallbladder carcinoma shows focal or asymmetric wall thickening, intraluminal polypoid mass, or liver invasion. Pericholecystic fat stranding may be present but clinical presentation is not acute. Hepatic invasion and biliary obstruction in advanced cases are distinguishing.
Distinguishing Feature
Wall thickening is seen in adenomyomatosis but comet-tail artifact (from cholesterol crystals in Rokitansky-Aschoff sinuses) and intramural cystic spaces are pathognomonic. Acute inflammatory findings (pericholecystic fluid, Murphy) are absent.
Distinguishing Feature
In xanthogranulomatous cholecystitis, the wall is markedly thickened with intramural hypodense nodules (xanthoma granulomas). Pericholecystic fat stranding may be present but intramural hypodense nodules are distinguishing. Can mimic carcinoma.
Urgency
urgentManagement
surgicalBiopsy
Not NeededFollow-up
specialist-referralAcute cholecystitis is a condition requiring urgent surgical consultation. Early laparoscopic cholecystectomy (within 72 hours of symptom onset) is standard treatment — according to Tokyo Guidelines 2018, management is planned based on severity grade (Grade I-III). Grade I (mild) early surgery, Grade II (moderate) early surgery + antibiotics, Grade III (severe — organ dysfunction) initial medical stabilization + percutaneous cholecystostomy followed by interval cholecystectomy. Complications: gangrene, perforation, pericholecystic abscess, biliary peritonitis. Biopsy is not needed — treatment is surgical excision.
Acute cholecystitis requires urgent surgical consultation. Early laparoscopic cholecystectomy (within 72 hours) is the standard treatment. Complications include gangrenous cholecystitis, perforation, and pericholecystic abscess.