Right Upper Quadrant Pain with Cholelithiasis but No Cholecystitis on CT
In a 73-year-old asplenic woman with RUQ pain and CT showing only cholelithiasis without cholecystitis, you should obtain a right upper quadrant ultrasound as the next diagnostic test, because CT has only 75% sensitivity for gallstones and cannot reliably exclude acute cholecystitis without IV contrast enhancement showing wall hyperemia and liver parenchymal changes. 1
Why the CT Finding Is Insufficient
CT detects only approximately 75% of gallstones because up to 80% are noncalcified and appear isodense to bile, making them invisible on standard CT imaging. 1, 2
CT without IV contrast can detect some features of acute cholecystitis (wall thickening, pericholecystic inflammation, gas, hemorrhage) but misses critical early findings such as gallbladder wall enhancement and adjacent liver parenchymal hyperemia—one of the earliest signs of acute cholecystitis. 3, 1
Even contrast-enhanced CT has limitations: it may not visualize all gallstones that are readily apparent on ultrasound, and the absence of CT findings does not exclude cholecystitis if the scan was performed without contrast or early in the disease course. 3
Next Diagnostic Step: Right Upper Quadrant Ultrasound
The American College of Radiology recommends ultrasound as the first-line imaging modality for suspected gallstone disease, with 96% accuracy for gallstone detection and 81% sensitivity and 83% specificity for acute cholecystitis. 1, 4
Key ultrasound findings to evaluate:
- Presence and location of gallstones, particularly impacted stones in the gallbladder neck or cystic duct 5
- Gallbladder wall thickening (>3 mm), wall hyperemia with elevated cystic artery velocities, and mucosal ischemic changes (loss of mucosal echogenicity) 5
- Gallbladder distention with a bulging fundus (tensile fundus sign indicating increased intraluminal pressure) 5
- Pericholecystic fluid and hyperechoic pericholecystic fat indicating inflammation 5
- Sonographic Murphy sign (though relatively insensitive, it is helpful when positive) 5
If Ultrasound Is Equivocal or Negative
When clinical suspicion for acute cholecystitis remains high despite negative or equivocal ultrasound, hepatobiliary scintigraphy (HIDA scan) is the gold standard diagnostic test, with 96-97% sensitivity and 90% specificity. 3, 4, 6
Alternative advanced imaging options:
MRCP has 85-100% sensitivity and 90% specificity for detecting cholelithiasis/choledocholithiasis and is superior to CT for evaluating suspected biliary sources of RUQ pain, particularly for visualizing the cystic duct and common bile duct. 3, 1
Contrast-enhanced CT should be reserved for suspected complications (emphysematous cholecystitis, gangrenous changes, perforation, abscess) or when broader differential diagnoses require evaluation. 3, 1
Management Based on Findings
If acute cholecystitis is confirmed:
Early laparoscopic cholecystectomy (within 1-3 days of diagnosis) is associated with improved outcomes compared to delayed surgery: fewer postoperative complications (11.8% vs 34.4%), shorter hospital stay (5.4 vs 10.0 days), and lower costs. 4
In patients over 65 years, laparoscopic cholecystectomy is associated with lower 2-year mortality (15.2%) compared to nonoperative management (29.3%). 4
If only symptomatic cholelithiasis without cholecystitis:
Approximately 35% of patients with untreated symptomatic gallstones develop complications or recurrent symptoms requiring cholecystectomy. 6
Referral to surgery within 2 weeks is recommended for symptomatic cholelithiasis regardless of severity, as the majority of patients rarely develop complications without first having biliary colic. 7, 8
Critical Pitfall in This Case
The asplenic status of this patient increases her risk for severe bacterial infections, making it particularly important not to miss or delay diagnosis of acute cholecystitis, which can rapidly progress to gangrenous changes and perforation. 5, 4
Do not rely solely on the CT report stating "no cholecystitis"—this may reflect technical limitations (no contrast, early disease) rather than true absence of inflammation. 3
The combination of RUQ pain and documented gallstones warrants ultrasound evaluation even when CT appears negative, because ultrasound provides superior assessment of gallbladder wall characteristics and real-time evaluation of tenderness. 1, 5