Magnetic resonance angiographic and clinical features of extracranial vertebral artery dissection
- aDepartment of Magnetic Resonance, bDepartment of Radiology, cDepartment of Neurology, University of Innsbruck, Austria
- Dr Stephan Felber, Department of Magnetic Resonance, University of Innsbruck, Anichstrasse 35, A - 6020 Innsbruck, Austria. Telephone 00512 504 4430; fax 00512 504 4419.
- Received 19 February 1997
- Revised 13 August 1997
- Accepted 15 August 1997
Abstract
OBJECTIVES Clinical data and neuroradiological findings of 19 patients with 20 vertebral artery dissections were analysed to describe the features of time of flight magnetic resonance angiography (MRA) for the diagnosis and follow up of this vascular disorder.
METHODS All patients underwent a combined MRI and MRA protocol with 1.5 T scanners, using a three dimensional flow compensated gradient echo sequence for MRA. Duplex sonography was performed on all patients and selective angiography was available from 17 vertebral artery dissections.
RESULTS MRI showed ischaemic lesions of the brain in 18 of 19 patients (95%). In the acute and subacute stage, MRA detected signal abnormalities within the dissected vertebral artery in 94% (16/17) and MRI was specific for a dissection in 29% (5/17). Sensitivity of selective angiography was 100% and specificity was 35% (6/17). Combination of the results of both methods increased the specificity to 50%. Duplex sonography was sensitive in 79% (15/19), but lacked specific results. Follow up magnetic resonance in 16 patients showed recanalisation of the dissected vessel in 10 (63%), persistent occlusion in five (31%), and a dissecting aneurysm in one (6%) patient.
CONCLUSIONS Magnetic resonance improves the triage for selective angiography and discloses complementary information for the diagnosis of vertebral artery dissection. If magnetic resonance identifies a double lumen or a mural haematoma with a stenosis or aneurysmal dilatation, invasive procedures can be omitted.
