Imaging Intracranial Vessel Wall Pathology With Magnetic Resonance Imaging
Current Prospects and Future Directions
To date, the probable cause of ischemic stroke is often inferred from the size and location of the infarct, in combination with an evaluation of the heart and the presence of extracranial arterial occlusion or high-grade stenosis.1 Currently used conventional lumenography-based methods such as digital subtraction angiography, computed tomography angiography, and magnetic resonance (MR) angiography are used to determine the presence of such an acute occlusion or high-grade arterial stenosis. From extracranial studies, it is known that luminal narrowing may be absent in patients with severe atherosclerosis owing to arterial remodeling.2–4 Therefore, these methods do not provide information about the underlying pathological processes, which most often involve the vessel wall.5 Vessel wall changes such as vessel wall thickening, enhancement, or the presence of vulnerable atherosclerotic plaques without luminal stenosis are therefore often missed but might be of importance for a better understanding of ischemic stroke.6 Furthermore, intracranial atherosclerosis is an important cause of ischemic stroke7 and often involves the vessel wall. Patients with intracranial atherosclerosis have high recurrent stroke rates,8 and increasingly more attention is being directed to the assessment of the intracranial vessel wall, necessitating an imaging technique directly assessing the intracranial vessel wall. MR imaging (MRI) seems the most promising technique to reliably image intracranial vessel wall pathologies because of its superior soft tissue contrast. Recent advances in MRI9 have made it possible to obtain information about these abnormalities within the intracranial vessel wall, which provides an imaging tool to investigate the role of intracranial vessel wall abnormalities in the diagnosis of stroke.
In this review, we discuss the current status of intracranial vessel wall MRI and its potential to identify different intracranial vessel wall pathologies. First, we present the state-of-the-art MRI methods to visualize the intracranial vessel wall …