Ultrafast magnetic resonance imaging protocols in stroke

Abstract

Stroke is the third leading cause of death and morbidity in the Western world. Ever since the publication of the major randomized trials showing the benefit of thrombolysis in early acute stroke, there has been growing impetus for the diagnosis of acute stroke to become a medical emergency. Currently, computed tomography (CT) remains the diagnostic method of choice in the assessment of acute strokes. It is practical, rapid, and widely available and, as used in these trials, can robustly exclude acute hemorrhage before potential thrombolysis. Although magnetic resonance imaging (MRI) has a number of advantages over unenhanced CT, the practicalities of performing MRI in the acute setting have hampered its widespread use. There are several reasons why speed of imaging is paramount in acute strokes. Firstly, such patients are often unwell and agitated and, as such, require close monitoring. Moreover, because of the short window within which intravenous thrombolysis can be given, time-consuming imaging studies decrease the therapeutic options available and likelihood of successful intervention. This review summarizes the latest developments in ultrafast imaging protocols that have the potential to improve practical feasibility, and thus propel MRI back to the forefront of acute stroke imaging.

Keywords::

• diffusion
• magnetic resonance angiography
• magnetic resonance imaging
• parallel imaging
• perfusion
• stroke