Plaque distribution of low-grade basilar artery atherosclerosis and its clinical relevance

Abstract

BackgroundThe underlying pathophysiology of BA distribution is unclear and intriguing. Using high-resolution magnetic resonance imaging (HR-MRI), we sought to explore the plaque distribution of low-grade basilar artery (BA) atherosclerosis and its clinical relevance.MethodsWe retrospectively analyzed the imaging and clinical data of 61 patients with low-grade atherosclerotic BA stenosis (<50%). On HR-MRI, the plaques were categorized based on the involvement of the ventral, dorsal, or lateral sides of BA wall. A culprit plaque was defined if it was on the same slice or neighboring slices of symptomatic pontine infarcts and played a probable causal role (dorsal plaques with median pontine infarcts or lateral plaques with ipsilateral pontine infarcts). The relationships between plaque distribution and clinical presentations were analyzed.ResultsTwenty-five symptomatic and thirty-six asymptomatic BAs with 752 HR-MRI image slices were studied. The average length of BA atherosclerosis plaques was 12.16 ± 5.61mm (10.30 ± 6.44mm in symptomatic and 13.46 ± 7.03mm in asymptomatic patients, p = 0.079). The plaque distribution was similar at ventral (29.0%), dorsal (37.6%) and lateral walls (33.1%). The BA plaques in symptomatic patients were more frequently located at the dorsal (42.5%) and lateral (41.2%) walls than at the ventral walls (16.1%; P < 0.05). Compared with symptomatic patients, asymptomatic patients more likely had their plaques distributed at the ventral walls (P = 0.022). Culprit plaques were observed in 85.0% (17/20) pontine infarcts in symptomatic patients and only 14.3% (2/14) silent pontine infarcts in asymptomatic patients (p < 0.001).ConclusionsLow-grade BA atherosclerosis has a long distribution and evenly involves ventral, dorsal and lateral walls. The plaques at dorsal and lateral walls are associated with symptomatic pontine infarcts but not with silent infarcts.Electronic supplementary materialThe online version of this article (doi:10.1186/s12883-016-0785-y) contains supplementary material, which is available to authorized users.

MRI of plaque characteristics and relationship with downstream perfusion and cerebral infarction in patients with symptomatic middle cerebral artery stenosis

“…The limitation of luminal stenosis to assess disease severity has been widely demonstrated in both intracranial and coronary arteries. 7,24,25 In our study, there was no significant difference in luminal stenosis grade between the patient groups with or without acute infarction, indicating that luminal stenosis alone is a relatively poor predictor of infarction. Our study demonstrated that MTT-ASPECTS and plaque enhancement grade could provide incremental information on the occurrence of cerebral infarction beyond luminal stenosis.…”

“…The limitation of luminal stenosis to assess disease severity has been widely demonstrated in both intracranial and coronary arteries . In our study, there was no significant difference in luminal stenosis grade between the patient groups with or without acute infarction, indicating that luminal stenosis alone is a relatively poor predictor of infarction.…”

“…Severe stenosis was traditionally considered to be an indicative of cerebral ischemia. However, it is increasingly recognized that the disconnect between stenosis severity and the presence of ischemic stroke is common . Recent studies using high‐resolution intracranial vessel wall imaging (HRVWI) have shown that atherosclerotic plaque characteristics, such as plaque enhancement and positive remodeling, are potential high‐risk biomarkers for ischemic stroke .…”

“…However, it is increasingly recognized that the disconnect between stenosis severity and the presence of ischemic stroke is common. [5][6][7] Recent studies using high-resolution intracranial vessel wall imaging (HRVWI) have shown that atherosclerotic plaque characteristics, such as plaque enhancement and positive remodeling, are potential high-risk biomarkers for ischemic stroke. 6,[8][9][10][11] Therefore, plaque characteristics may be a link between stenosis and ischemia.…”

Neovascularization in Vertebral Artery Atheroma—A Dynamic Contrast-Enhanced Magnetic Resonance Imaging-Based Comparative Study in Patients with Symptomatic and Asymptomatic Carotid Artery Disease

“…In clinical practice, duplex imaging is usually used for assessing the direction of blood flow in the VAs and for indirect assessment of VA stenosis by calculating the velocity increase across a stenosis. Imaging modalities such as high resolution magnetic resonance (MR) imaging have been successfully used for vessel wall imaging of the vertebrobasilar circulation [11][12][13] . However, these reports have mainly focused on morphometric assessment of atheromatous plaques.…”