INTESTINAL AND PERITONEAL BLEEDING - DETECTION WITH AN INTRAVASCULAR CONTRAST AGENT AND FAST 3-DIMENSIONAL MR-IMAGING - PRELIMINARY EXPERIENCE FROM AN EXPERIMENTAL-STUDY

PURPOSE: To assess the ability to detect and localize intestinal and p eritoneal bleeding with an intravascular contrast agent and fast three -dimensional (3D) magnetic resonance (MR) imaging. MATERIALS AND METHO DS: An intravascular contrast agent (NC100150 Injection) was administe red into small-bowel specimens at five flow rates; the specimens were imaged with a 3D gradient-echo (CRE) sequence at 1-minute intervals. R adionuclide studies with technetium-99m pertechnetate were performed i n the same manner. Subsequently, the MR imaging technique was assessed in vivo. Two intraluminal intestinal and one hepatic bleeding sites w ere created in an anesthetized pig. Three-dimensional CRE imaging data sets were acquired after intravenous injection of the contrast agent. Imaging findings were confirmed with macroscopic inspection. RESULTS: Contrast material injected at 0.5-2.0 mL/min was detected with both r adionuclide and MR imaging after 1 minute. An accumulated volume of 0. 2 mL was necessary to demonstrate the bleeding site. In vivo, all blee ding sites were readily detected on MR images. Contrast material accum ulated in the intestines and peritoneal space. CONCLUSION: In conjunct ion with an intravascular contrast agent, 3D MR imaging allows detecti on and localization of gastrointestinal bleeding. The extent of the bl eeding can be determined with repeat data acquisitions.