Arjen Lindenholz

61 The Use and Pitfalls of Intracranial Vessel Wall Imaging 3 Table 3. Commonly seen imaging characteristics for different intracranial vessel wall diseases Vessel wall pathology Stenosis (MRA / CTA) VW thickening (eccentric / concentric) Location Enhancement† Special considerations Figure Intracranial atherosclerosis 35,42,47,56,70,72 +/- Eccentric More widespread Distal ICA / vertebral Focal lesions +/- Plaque characterization * Intraplaque hemorrhage * Figure 4 CNS vasculitis 73,74 + Concentric More widespread Long trajectory ++ Effect of steroid therapy Guiding best location for biopsy Figure 9 Moyamoya disease 75-79 +/- Concentric Distal ICA Proximal MCA +/- - Figure 10 Arterial dissection 80-83 ++ Eccentric Distal ICA / vertebral + Detection of hematoma & flap Added value of fat suppression in case of an extracranial dissection Figure 11 Intracranial aneurysm 69,84-87 +/- Often enhances when symptomatic Difficult to assess when SAH present Figure 12 RCVS 73,74,88 + Concentric More widespread - String-of-beads on angiography - Iatrogenic 54,55 (after thrombectomy) +/- Eccentric / concentric Thrombectomy site + - Figure 8 Stenosis and enhancement are shown on a scale of 5: -- (virtually never present), - (often not present), +/- (equally present and not present), + (often present) and ++ (virtually always present). CNS, central nervous system; CTA, Computed Tomography Angiography; ICA, internal carotid artery; MCA, middle cerebral artery; MRA, Magnetic Resonance Angiography; RCVS, reversible cerebral vasoconstriction syndrome; SAH, subarachnoid hemorrhage; VW, vessel wall. † Concordant with contrast enhancement of extravascular pathology, contrast enhancement of intracranial vessel wall pathology could reflect a more active phase of disease. 74 *Plaque characterization has mainly been performed in the Asian population, in which large multi-component atherosclerotic plaques are significantly more prevalent. Several case series have shown the possibility of detecting intraplaque hemorrhage; 22,89-93 however, postmortem studies suggest that intraplaque hemorrhage has a lower prevalence in intracranial plaques compared with extracranial (carotid) plaques; 6,47,94 therefore, its role so far remains elusive.