Cholecystokinin-stimulated mebrofenin ( Tc-Choletec) hepatobiliary scintigraphy in asymptomatic postcholecystectomy individuals: assessment of specificity, interobserver reliability, and reproducibility

Cholecystokinin-stimulated hepatobiliary scintigraphy (CCK-HBS) is a noninvasive method reported to be highly accurate in the diagnosis of sphincter of Oddi dysfunction. Our primary aim was to assess the specificity of CCK-HBS by evaluating its ability to exclude disease in 20 asymptomatic postcholecystectomy individuals. Secondary aims were to assess the interobserver reliability in scoring the CCK-HBS examinations between three blinded observers and to assess reproducibility of CCK-HBS repeated in the same individuals. Twenty asymptomatic postcholecystectomy individuals with normal liver serum chemistries underwent CCK-HBS on two separate occasions. Three nuclear medicine specialists read each CCK-HBS study in a blinded fashion. There was good agreement between the three observers reading the same scans for both the first scan (κ = 0.554) and the second scan (κ = 0.507). There was poor agreement between the first and second scans on the same patient, read by the same nuclear medicine specialist (κ = 0.062–0.385). The overall specificity of the CCK-HBS score was 77.5%; however, the specificity was only 60% when a true negative was defined as two negative CCK-HBS examinations. Quantitative CCK-HBS is of poor specificity in asymptomatic postcholecystectomy individuals. Hence, it is of questionable value in excluding sphincter of Oddi dysfunction in patients suspected to suffer from this disorder.