Current Status of Clinical Magnetic Resonance Imaging for Plaque Characterisation in Patients with Carotid Artery Stenosis

Abstract

Based on current literature, it appears premature for routine application of MRI as an imaging modality to assess carotid plaque characteristics associated with plaque vulnerability. Although MRI still holds promise, clinical application for plaque characterisation would require consensus regarding MRI settings and confirmation by histology. Predefined protocols for histology and MR imaging need to be established.

Imaging Intracranial Vessel Wall Pathology With Magnetic Resonance Imaging

“…However, at this moment, the lack of validation of MRI with histology to demonstrate the feasibility of intracranial vessel wall MRI in characterizing plaque components makes it difficult to establish the origin of the lesion on the basis of in vivo data only. For the extracranial arteries, histological validation is already widely available because carotid specimens are obtained with endarterectomy 75,76 and the in vivo MRI can be performed before surgery. For intracranial arteries, however, only a few studies addressed this issue.…”

Intraplaque High-Intensity Signal on 3D Time-of-Flight MR Angiography Is Strongly Associated with Symptomatic Carotid Artery Stenosis

“…4 However, a significant barrier to the widespread use of IPH assessment as a measure of embolic stroke risk has been that most studies have relied on high-resolution imaging by using specialized, dedicated MR imaging surface carotid coils 12 or black-blood coronal T1-weighted fat-suppressed MR imaging techniques. 9 Neither of these techniques are part of the standard sequences routinely obtained in MRA examinations, which rely on TOF techniques to assess luminal diameter stenosis.…”

“…[1][2][3] However, with recent developments in MR imaging technology, it is possible to assess the composition of atherosclerotic carotid lesions to determine the presence of complicated or advanced plaque elements that are at greater risk to cause ischemic symptoms. [4][5][6] One such component of carotid plaque that has been identified as a component of advanced atherosclerotic lesions is intraplaque hemorrhage (IPH). When present in carotid atherosclerotic plaque, IPH has been associated with previous 7,8 and future 9 stroke and has been proposed as a possible marker of not only plaque inflammation 10 but also of generalized cardiovascular risk.…”

CT Angiographic Features of Symptom-Producing Plaque in Moderate-Grade Carotid Artery Stenosis

“…4,6,7 Although hypoperfusion and resultant slow flow from carotid disease likely play a role in a subset of strokes occurring in carotid stenosis, plaque instability causing distal embolus may be a relatively more influential etiologic factor for stroke in carotid disease in general. 8 Although multisequence MR imaging characterization of plaque has allowed the in vivo discrimination of high-risk plaque tissue elements, [9][10][11] its use in clinical practice has been limited, given the time, expense, and challenge of performing multisequence carotid plaque MR imaging by using a dedicated carotid coil. CTA-based measurements of soft and hard (calcified) plaque determined on axial CTA source images have recently been proposed as potential simple alternative markers of vulnerable plaque in high-grade ICA stenosis.…”