DETECTION OF REPERFUSED ISCHEMIA OF THE RAT INTESTINE - VALUE OF MAGNETIC-RESONANCE-IMAGING WITH SMALL-MOLECULAR-WEIGHT DYSPROSIUM AND GADOLINIUM CHELATES

Rationale and Objectives. The authors assessed whether the small-molec ular-weight magnetic resonance (MR) imaging contrast agents dysprosium diethylenetriamepentaacetic acid bismethylamide (sprodiamide injectio n), which enhances T2, and gadolinium diethylenetriamepentaacetic aci d bismethylamide (gadodiamide injection), which enhances T1, could imp rove the detection of reperfused ischemia of the rat intestine, Method s. Eighteen rats were subjected to vascular occlusion of the distal il eum for 30 minutes, followed by reperfusion. Ten minutes after reperfu sion, T1- and T2-weighted spin-echo (SE) images were obtained before a nd after administration of sprodiamide, gadodiamide, or both, The same imaging protocol was applied in another group of 18 rats subjected to 10 minutes of occlusion and reperfusion. Histologic examination of th e intestine was performed after MR imaging, Results. Villous injury (i e, denudation) was observed in most cases after 30 minutes of occlusio n, but not after 10 minutes of occlusion. After 30 minutes of occlusio n, the superficial part of the ischemic intestine was hyperintense to the normal intestine on unenhanced T2-weighted images. Administration of sprodiamide improved the contrast between the normal and ischemic i ntestine on T2-weighted images, and administration of both gadodiamide and sprodiamide improved the contrast on T1- and T2-weighted images. After 10 minutes of occlusion, no contrast was discernible before or a fter contrast material administration.Conclusion. These results sugges t that the detection of reperfused intestinal ischemia of sufficient d uration to cause villous injury can be improved by using sprodiamide i njection alone or in combination with gadodiamide.