American Journal of Roentgenology, Vol 161, 409-416, Copyright © 1993 by American Roentgen Ray Society
Value of brominated fluorocarbons for the radiographic diagnosis of small-bowel obstruction: comparison with other contrast agents in rats
SL Wootton, BD Coley, SV Hilton, DK Edwards 3d, JR Amberg and RF Mattrey
Department of Radiology, University of California, San Diego, Medical Center 92103.
OBJECTIVE. The disadvantages of water-soluble gastrointestinal contrast
agents include high osmolality, contrast dilution, and severe toxicity if
aspirated. Perfluorocarbons are nontoxic in the lung and peritoneal cavity.
Because perfluorocarbons are immiscible with water, they have no osmotic
effect and cannot be diluted. Because these properties offer theoretical
advantages over traditional gastrointestinal contrast agents, we compared
two perfluorocarbons with barium and ionic and nonionic iodinated contrast
material in a rat model of small-bowel obstruction. MATERIALS AND METHODS.
Twelve groups of six rats each had ligation of the terminal ileum
(obstruction model) or of the terminal ileum and mesenteric artery
(obstruction with ischemia model). Each rat received 3 ml of barium,
meglumine sodium diatrizoate, iohexol, neat perfluorooctyl bromide, neat
perfluorohexyl bromide, or saline (control animals). Contrast media were
given at the recommended concentrations, and their progression was
evaluated on serial radiographs by an observer who was not aware of the
model or the contrast medium given. When one contrast material reached the
point of obstruction, all rats in the group were sacrificed and a final
radiograph was obtained. Three radiologists, who were not aware of the
contrast medium given, on two separate occasions independently reviewed the
radiographs and ranked the contrast agents for their relative radiopacity,
mucosal definition, speed of transit, gastric retention, and bowel
distension. RESULTS. When data from both models were combined,
perfluorocarbons were judged on the final image to be the most radiodense,
to provide the sharpest mucosal detail, to have the least gastric
retention, and to have faster progression than barium. Whereas meglumine
sodium diatrizoate and iohexol reached the point of obstruction more
rapidly than the perfluorocarbons and barium, they had the greatest gastric
retention, caused the most bowel distension, and were the least radiopaque.
CONCLUSION. Our results show that the radiopaque perfluorocarbons are
suitable as gastrointestinal contrast agents and have favorable
radiographic characteristics in this animal model. When these results are
combined with the low-toxicity profile of perflubron, clinical evaluation
of this agent for the radiographic assessment of bowel obstruction is
warranted.