Three-dimensional contrast-enhanced MR angiography of endovascular covered stents in patients with peripheral arterial occlusive disease.

Abstract

Three-dimensional contrast-enhanced MR angiography was performed to study MR characteristics of Hemobahn devices. Changes in endoluminal signal intensities and the precision of the endoluminal diameter measurement were investigated in phantom studies for different concentrations of gadopentetate dimeglumine. Before and after the Hemobahn devices had been implanted, 10 patients with peripheral arterial occlusive disease were examined on MR imaging and three-dimensional contrast-enhanced MR angiography. Phantom experiments using three-dimensional MR angiography showed stent-related signal void as a dark ring in the axial image orientation, providing a precise delineation of the stent--vessel border (mean endoluminal diameter, 8.2 mm; SD, 0.6 mm). Changes in endoluminal signal intensity were evaluated quantitatively. Stent-related artifacts did not compromise diagnostic imaging quality. All Hemobahn devices were found to be patent without migration of an implanted graft. In one patient, an extensive perigraft reaction (edema and contrast-enhanced perivascular tissue) was postinterventionally detected on MR imaging and corresponded to clinically evident postimplantation symptoms. Three-dimensional contrast-enhanced MR angiography is a suitable tool to follow up the implantation of Hemobahn devices and to detect intra- and extraluminal abnormalities.