The value of HIDA scans in the initial evaluation of patients for cholecystitis.

One hundred twenty-two consecutive patients who had hepato-iminodiacetic acid (HIDA) scans over a 5-month period were reviewed. These scans were found to have 94% sensitivity, but only 36% specificity for correctly diagnosing pathological variants of cholecystitis. Frequently, HIDA scans were misinterpreted to show common bile duct obstruction (CBDO); only 20% of cases of CBDO suggested on HIDA could be confirmed surgically. Sonography gave 88% to 90% sensitivity and 91% specificity in correctly diagnosing pathological variants of cholecystitis and correctly demonstrated CBDO in 80% of the cases. As first-line studies to evaluate biliary tract disease, HIDA scans are costly and should be eliminated.