[Perioperative evaluation of internal carotid artery stenoses: value of multislab MR angiography].

Purpose: Evaluation of the diagnostic potential of high resolution multislab 3D-TOF-magnetic resonance angiography (MRA) in the pre- and postoperative assessment of carotid artery stenosis in comparison to conventional angiography.
Methods: 120 Patients were evaluated with MRA and DSA prior to carotid endarterectomy (CEA). Additionally 26 patients underwent MRA after CEA. All MRA examinations were carried out on a 1.5 T MR-unit (Siemens Magnetom SP63) using a Helmholtz surface coil. For the visualization of the vascular structures in the head and neck region, flow compensated GE-sequences were employed. Both original MRA data set and MIP angiograms were included in the evaluation. The determination of the extent of stenoses was performed according to the recommendation of NASCET.
Results: In 195 (92.9%) of 210 cases included in the review MRA revealed the same results as DSA (grade I+II: 114, grade III: 24, grade IV: 44, grade V: 13). None of the cases showed a deviation higher than one grade. The sensitivity and specificity of hemodynamic relevant stenoses (> 60%) was 0.964 respectively 0.952. 23 out of 26 patients with postoperative follow-up examination revealed regular reperfusion of the former affected internal carotid artery. The remaining 3 patients showed a restenosis of the operated vessel (n = 2) and a reocclusion of the ICA after surgery (n = 1). MRA proofed to be an accurate and reliable method for the perioperative evaluation of vascular structures in the head and neck region. Despite of some drawbacks MRA reached a high accuracy in the diagnostic imaging before and after CEA. MRA is accurate and useful in screening carotid artery diseases. The indication of MRA employment therefore not only covers the screening of vascular structures but also includes pre- and postoperative evaluation of vascular stenoses.