Computed tomographic analysis of gallstones. An in vitro study

Area of Science:

• Medical Imaging
• Gastroenterology
• Biochemistry

Background:

• Accurate prediction of gallstone dissolution is limited by the inability of current biliary studies to differentiate stone composition.
• Gallstone characterization is crucial for determining appropriate treatment strategies, including medical dissolution therapy.

Purpose of the Study:

• To evaluate the predictive value of computed tomography (CT) for classifying gallstone types and predicting their chemical dissolution.
• To establish a correlation between CT numbers (Hounsfield units) and gallstone composition.

Main Methods:

• Sixty-five gallstones were analyzed in vitro using CT.
• Thirty stones underwent simultaneous CT and infrared spectroscopy analysis to correlate CT numbers with stone composition.
• Thirty-five gallstones were subjected to CT analysis followed by in vitro dissolution testing in a chenodeoxycholate solution.

Main Results:

• CT analysis revealed significantly different Hounsfield unit (HU) values for cholesterol (-87.3 +/- 14.5 HU) and pigment gallstones (162 +/- 27.6 HU).
• A linear correlation was observed between CT numbers and cholesterol content.
• Fifty percent (13/26) of gallstones with CT values below 50 HU completely dissolved within three weeks, while no stones with CT values above 50 HU dissolved.

Conclusions:

• CT analysis provides accurate classification of gallstone types.
• CT imaging is a valuable tool for predicting the in vitro chemical solubility of gallstones.
• CT-based gallstone characterization can guide treatment decisions for gallstone dissolution therapy.