[en] Objective: To investigate the feasibility of catheterization of cerebral arteries under the real-time MR imaging guidance in experimental pigs. Methods: Ten small-sized female pigs were selected for this study. Via the femoral access, percutaneous catheterization with a 3 F active MR-tracking microcatheter was performed under real-time MRI guidance and the microcatheter was separately placed into bilateral ascending pharyngeal arteries. After the procedure, all the pigs were sacrificed and sent for pathologic examination. Gross pathologic examination of aortic arches, brachio-cephalic arteries, carotid arteries and ascending pharyngeal arteries was performed to search for the perforation and dissection. Results: MR angiography revealed that in pigs the bilateral ascending pharyngeal arteries formed an arteriolar network at the cranial base, supplying blood flow to the brain. Catheterization of ascending pharyngeal arteries from the femoral artery access was successfully performed in all 10 pigs with the help of real-time MR imaging-guidance. A single procedure took about 4-12 minutes. Macroscopically, no evidence of vascular injury of aortic arches, brachio-cephalic arteries, carotid arteries and ascending pharyngeal arteries was found. Conclusion: Under real-time MRI guidance the catheterization of cerebral arteries can be correctly and quickly accomplished in experimental pigs. (authors)

[en] Objective: To investigate the feasibility of thrombolytic therapy for cerebral arteries in experimental pigs under real-time MR imaging guidance. Methods: Ten domestic female pigs (produced in U.S.A.) were enrolled in this study. After puncturing femoral artery with percutaneous technique, the bilateral ascending pharyngeal arteries were catheterized with 3 F active MR-tracking microcatheter under the guidance of real-time MR imaging. Then, aged thrombi were injected via the microcatheter to occlude the pharyngeal arteries. After 30-60 minutes, 500,000-750,000 units of urokinase were infused through the microcatheter into either one of the occluded ascending pharyngeal arteries for thrombolysis. Intraarterial contrast enhanced MRA and T1 fat suppressed coronal MR images were obtained to assess the vessel occlusion and the results of thrombolysis. Results: MR angiography revealed that the major cerebral blood supply in pigs was obtained from the basicranial micro-vascular network which was formed by bilateral ascending pharyngeal arteries. Catheterization of ascending pharyngeal arteries via the femoral artery access was successfully performed in all 10 pigs under the guidance of real-time MR imaging. Both ascending pharyngeal arteries were totally occluded in all pigs after injection of aged thromboli. After urokinase infusion into the ascending pharyngeal arteries, the blood clots were resolved with re-established blood flow. Conclusion: It is feasible to perform thrombolytic therapy for cerebral arteries under real-time MR imaging guidance. (authors)