The scintigraphic score: Assessment of interobserver variability and correlation with sphincter of Oddi manometry (SOM) in patients with suspected sphincter of Oddi dysfunction (SOD)

The scintigraphic score (SS) during cholecystokinin (CCK)-stimulated hepatobiliary scintigraphy (HBS) was repotted to have a perfect sensitivity and specificity of 100% in predicting SOD and to yield a high concurrence rate between two observers. ¹ Basal SO pressures (BSOP) have been found to be the most reliable predictor of outcome from sphincterotomy in patients with SOD. AIMS: To evaluate the SS with respect to agreement on total score between three observers, frequency of concordance in classifying scans as normal or abnormal, and ability to detect elevated BSOP. METHODS: Thirty post-cholecystectomy patients (27F, 3M) classified as Geenen-Hogan Type II (11), and III (19) underwent HBS as described by Sostre et al. ¹ Three blinded nuclear medicine specialists independently reviewed each examination and assigned a scintigraphic score; differences in classifying scans as normal or abnormal were resolved by consensus. ERCP with SO manometry (SOM) with meperidine and midazolam sedation was performed within 48 hours of the HBS using a water perfused triple-lumen catheter with one port sacrificed for aspiration. SOM was considered abnormal if BSOP was ≥ 40 mmHg in both perfusion ports. Two patients were excluded from manometric correlation because of failed biliary manometry. RESULTS: Kendall's coefficient of concordance for the total score between the three observers was 0.84 with significance of p<0.001. However, concordance between observers in classifying scans as normal or abnormal was 24/30 (80%). Scintigraphy correlated poorly with SO manometry, as seen in the table. SOM HBS BSP≥40mmHg BSP< 40 mmHg Abnorma 7 6 Normal 8 7 Sens = 47 % Spec = 54% PPV = 54 % NPV = 47% The scintigraphic score assigned by three blinded observers yielded reasonable agreement. However, there was significant discordance in classifying scans as normal or abnormal in patients with suspected SOD. In addition, the scintigraphic score was a poor predictor of elevated BSOP. CONCLUSIONS: This study suggests that CCK-stimulated HBS is not an accurate predictor of elevated BSOP in post-cholecystectomy patients.