Computed tomography in predicting the efficacy of oral cholelitholysis with bile acids.

The efficacy of oral cholelitholytic therapy with chenodeoxycholic acid (CDCA) and ursodeoxycholic acid (UDCA) in 137 patients with gallstones was studied in relation to their CT patterns. The best dissolving results were obtained in patients with the stones in isodensity and faint category (< 50 Hu) on CT. The stones with high density or heterogeneous calcification on CT were insoluble, and therefore, were contraindicated for oral cholelitholytic therapy. The attenuation value of stones was classified as complete dissolution ranged from -2 to 35 Hu (14 +/- 12 Hu, n = 13), and their upper limit of 95 percentiles was 33.4 Hu. CT analysis improved the predictability of dissolving gallstones in comparison with plain abdominal radiography or oral cholecystography (OCG). The complete dissolving rate increased from 9.49% (13/137) in patients selected by classic X-ray to 40.7% (11/27) in isodensity category on CT. Besides, radiolucent gallstones, which showed no obvious filling defect on OCG but distinct echo and shadow on B-type ultrasonography, were also insoluble.