Radiology, Vol 175, 479-482, Copyright © 1990 by Radiological Society of North America
Iodinated contrast medium as an aid to gallstone dissolution with methyl tert-butyl ether: in vitro study
J Zhou, SH Lee, B Rawat, JS Fache, U Maciejewska and HJ Burhenne
Department of Radiology, University of British Columbia, Vancouver, Canada.
Methyl tert-butyl ether (MTBE) floats on bile, whereas gallstones sink.
Therefore, stones and MTBE are separated by a layer of bile. This study
investigates the effect of contrast medium on flotation of gallstones in
bile and its role in stone and fragment dissolution with MTBE. Fresh human
gallstones, both calcified and noncalcified, from different patients were
tested in vitro for flotation in bile, with and without addition of
contrast medium. All gallstones or fragments sank in bile before the
introduction of contrast medium. Noncalcified stones floated when the
contrast medium-bile volume ratio was 1:6 or more, while double this amount
of contrast medium was required to float calcified stones. Fragments did
dissolve somewhat in MTBE in the presence of bile alone, but when contrast
medium was added, almost complete dissolution occurred. This is thought to
be due to increased contact between the fragments and MTBE, both floating
on the contrast medium-bile mixture. Contrast material may be a useful
adjuvant in gallstone dissolution therapy with MTBE in vivo.
