Intestinal and peritoneal bleeding: detection with an intravascular contrast agent and fast three-dimensional MR imaging--preliminary experience from an experimental study.

PURPOSE: To assess the ability to detect and localize intestinal and peritoneal bleeding with an intravascular contrast agent and fast three-dimensional (3D) magnetic resonance (MR) imaging. MATERIALS AND METHODS: An intravascular contrast agent (NC100150 Injection) was administered into small-bowel specimens at five flow rates; the specimens were imaged with a 3D gradient-echo (GRE) sequence at 1-minute intervals. Radionuclide studies with technetium-99m pertechnetate were performed in the same manner. Subsequently, the MR imaging technique was assessed in vivo. Two intraluminal intestinal and one hepatic bleeding sites were created in an anesthetized pig. Three-dimensional GRE 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 radionuclide and MR imaging after 1 minute. An accumulated volume of 0.2 mL was necessary to demonstrate the bleeding site. In vivo, all bleeding sites were readily detected on MR images. Contrast material accumulated in the intestines and peritoneal space. CONCLUSION: In conjunction with an intravascular contrast agent, 3D MR imaging allows detection and localization of gastrointestinal bleeding. The extent of the bleeding can be determined with repeat data acquisitions.