Evaluation of 4D Magnetic Resonance Angiography (K-t Blast) of Supraortic Vessels in Acute Ischemic Stroke Patients

The Magnetic Resonance angiography (MRA) of supraaortic vessels is essential for the etiologic of stroke. However, the techniques usually used provide only static evaluation (degree of stenosis, occlusion) but not dynamic. An ultra-fast 3D MRA originally developed for the cardiac imaging, k-t blast (Broad-use Linear Acquisition Speed-up Technique) could be used to review the supraaortic vessels. This MRA offers the following advantages: short acquisition time, wide spatial coverage (of the thoracic aorta to the distal encephalic arteries), 3D spatial resolution and high temporal resolution. These qualities are even more optimal with a high magnetic field (3T). The high temporal resolution is interesting because it provides to repeat a volume every eight seconds and thus to have a dynamic evaluation of vascular filling and to assess the vascular supply of the infarcted territory. This sequence is classified as a 4D MRA.