DISSOLUTION OF CALCIFIED GALLSTONES .1. CORRELATION OF IN-VITRO DISSOLUTION KINETICS IN METHYL TERT-BUTYL ETHER WITH PATTERNS OF CALCIFICATION BY COMPUTED-TOMOGRAPHY

RATIONALE AND OBJECTIVES. The authors evaluated the relationship betwe en stone computed tomography (CT) attenuation patterns and the kinetic s of dissolution with methyl tert-butyl ether (MTBE). METHODS. Single moderately and heavily calcified gallstones from 40 patients were sele cted from a gallstone library and classified for pattern of calcificat ion by in vitro CT scan (dense, rim, core, and laminated). Each stone was placed in a 10-mL aliquot of MTBE for 24 hours. Stone residue was blotted dry and weighed at 8, 16, and 24 hours. Results were normalize d with respect to stone size. RESULTS. Only 1 of 40 (4%) specimens dis solved to particulate matter that was smaller than 2 mm. All (6 of 6) stones that were densely calcified showed virtually no dissolution. Th e rate of gallstone dissolution varied temporally within the rim, core , and laminated stone categories and was related to the composition of the layer exposed to the solvent at any given time. CONCLUSION. The s uccess and rate of dissolution may be predicted by the pattern of calc ification as determined by computed tomography (CT).