The Overuse of Hepatobiliary Scintigraphy (HIDA) Scans: Are We Unnecessarily Using Nuclear Medicine Resources Instead of Proven Clinical Guidelines for Diagnosing Acute Cholecystitis?

Background Gallstone disease significantly burdens the United States healthcare system. While ultrasonography (US), physical exam, and laboratory findings are the recommended primary workup and diagnostic modalities, hepatobiliary scintigraphy (HIDA) scans are occasionally used as an adjunct for diagnosis. This study evaluates HIDA scan utilization in comparison to clinical and US findings based on the Tokyo guidelines for diagnosing acute cholecystitis.

LC determination of impurities in methoxsalen drug substance: isolation and identification of isopimpinellin as a major impurity by atmospheric pressure chemical ionization LC/MS and NMR.

A gradient elution LC method was developed to separate methoxsalen from three of its known impurities: isopimpinellin, bergapten, and ammidin. The method employs a methanol-6%THF (aq) mobile phase, phenyl column, and detection at 254 nm. The gradient LC procedure was applied to seven lots of methoxsalen from five different manufacturers.