Three-dimensional sonographic evaluation of gallbladder contractility: comparison with cholescintigraphy

PURPOSE: To compare three-dimensional sonography (3D US) with quantitative cholescintigraphy for assessing gallbladder contractility. METHODS: Gallbladder radioactivity was assessed in 35 patients with suspected gallbladder disease using a gamma camera 5, 30, 60, and 90 minutes after technetium 99m (Tc-99m) DISIDA injection and 30 and 60 minutes after ingestion of a high-fat meal. Immediate gallbladder images were obtained via 3D US. Gallbladder radioactivity at 120 minutes after injection of Tc-99m DISIDA was defined as 100%, and gallbladder contractility was calculated. Gallbladder volume on 3D US was calculated using a dedicated software. Pearson correlation analysis and simple linear regression analysis were used. RESULTS: The mean gallbladder volume on 3D US was 25.3 ml after fasting and 6.6 ml after a high-fat meal. The mean gallbladder contractility index was 77.7% on cholescintigraphy (range, 18-99) and 73.4 on 3D US (range, 16.7-97.3). A linear correlation between cholescintigraphy and 3D US contractility indices was observed. The r value on Pearson analysis was 0.92 and R(2) of the coefficient of determination was 0.85. The difference in measured contractility between the 2 methods ranged from +21.5% to -15.0% (mean +/- SD, 4.4 +/- 8.7%). CONCLUSIONS: 3D US is a reliable and easy method for clinical measurement of the volume of the gallbladder and its contractility.