Magnetic resonance imaging for the visualization of cholesterol gallstones in hamster fed a new high sucrose lithogenic diet.

Cholesterol gallstone induction in hamster gallbladder is usually achieved by specific diets. An X-ray in vivo follow-up of cholelithiasis development in this species is impossible, since cholesterol gallstones are transparent as long as they are not calcified. Moreover, their size (0.2 to 1 mm) also prevents their detection by ultrasonography. The current study presents an in vivo cholesterol gallstone detection by magnetic resonance imaging in hamsters fed a new high sucrose diet containing a low proportion of cholesterol (0.015%) and a normal ratio of lipids (10%). The diet produced gallstones and an increase in the cholesterol saturation index in about 50% of animals after a 5-week feeding period. The visualization of gallstones by magnetic resonance imaging in anaesthetized animals required synchronization between breathing movements and image acquisition. A high magnetic field was also necessary to allow a fine image resolution, adapted to gallstone size. Two major advantages of this technique are a direct selection of lithiasic animals with a functional gallbladder (in spite of the presence of gallstones) and a possible adjustment of the treatment period of potential litholytic drugs.