Recent advances in gallstones therapy, such as chemical dissolution, and extracoporeal shockwave lithotripsy, have generated interest in the ability of imaging methods to determine the chemical composition of gallstones. The chemical dissolution
of
gallstones can not be accurately predicted since available biliary studies often do not distinguish stone types. Although not proposed as a screening tool, computed tomography(CT) is the most sensitive method to measure the density of gallstones.
The
aim of our study was, therefore, to elucidate whether CT-measurement of stone density allows to predict the chemical composition of gallstones.
Thirty senen samples from 30 gallstones were analyzed in vitro. The attenuation values (Hounsfield unit/HU) were measured by GE 9800 Hilignt, 120 kVp, 100 mA CT scanner in vitro After imaging, these gallstones were dried and chemically analyzed.
Chemical analysis provided quantitative identification of stone component such as cholesterol, calcium, bilirubin, and residue. According to this analysis 7(19%) were classified as cholesterol stones, 18(49%) as mixed and 12(32%) as pigment
stones.
When
the chemically analysed cholesterol content of each stone is compared with the CT attenuation value significant negative correlation is demonstrated. The positive correlation between CT density and calcium content is demonstrated. The attenuation
values
of cholesterol stones amounting to mean-19 HU differed significantly from pigment stones(mean 778 HU).
Since analysis of gallstones by CT scan provides more exact discrimination between cholesterol and pigment stones, we consider. CT-measurenent of gallstones to improve success rate of therapy in vivo.
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