Magnetic resonance imaging of acute occlusive intestinal ischemia

The mortality of acute superior mesenteric artery occlusion and mesenteric infarction remains high, in part because of the failure to identify the patients with the disorder. A reliable noninvasive diagnostic study may facilitate earlier definitive diagnosis and therapy. Proton magnetic resonance imaging may offer a noninvasive diagnostic alternative. We examined this possibility by using an experimental rabbit model of acute superior mesenteric artery occlusion in this study. Animals were scanned 1 hour after the ischemic insult. Relative intestinal wall signal intensity was increased in experimental (ischemic) animals when compared to sham operated controls on T₂-weighted (4.35 ± 0.5 vs 2.57 ± 0.31, p <0.02) and proton spin density-weighted images (2.1 ± 0.2 vs 1.4 ± 0.21, p <0.05). Significant increases in image intensity were found on T₂-weighted and proton spin density images when compared to control animals. Differences between groups could be further highlighted after the administration of a paramagnetic contrast agent gadolinium diethyltriamine pentacetic acid on T₁-weighted images. The data from this preliminary study demonstrate that proton magnetic resonance imaging may be used to discriminate between ischemic and nonischemic small intestine. This noninvasive tool may someday become clinically useful to enhance our diagnostic capabilities when a diagnosis of acute superior mesenteric artery occlusion is being entertained.