Regression of Plaque Enhancement Within Symptomatic Middle Cerebral Artery Atherosclerosis: A High-Resolution MRI
Wen-Jie Yang1, Jill Abrigo2, Yannie Oi-Yan Soo3
1The Russell H. Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins University, Baltimore, MD, United States.
Abstract:
Objective: Contrast enhancement is a vital feature of the intracranial atherosclerotic plaque on high-resolution magnetic resonance imaging (HRMRI), but its clinical significance is still unclear. We aimed to quantitatively assess plaque enhancement patterns in the middle cerebral artery (MCA) atherosclerotic plaque. Methods: We conducted a cross-sectional study by prospectively recruiting stroke or transient ischemic attack patients with >30% of MCA stenosis of either side. All patients underwent contrast-enhanced HRMRI scans. Enrolled patients were classified into acute phase (<4 weeks), subacute phase (4-12 weeks) and chronic phase (>12 weeks) groups based on the time interval from stroke onset to imaging scan. Plaque enhancement index was calculated for each MCA lesion at the maximal narrowing site. Results: We identified a total of 89 MCA plaques [53 (60%) symptomatic and 36 (40%) asymptomatic; 57 (64%) acute, 18 (20%) subacute and 14 (16%) chronic] in 58 patients on HRMRI. Among the acute lesions, symptomatic plaques had a significantly stronger plaque enhancement than asymptomatic plaques (symptomatic vs. asymptomatic: 38.9 ± 18.2 vs. 18.2 ± 16.2, p < 0.001). Among the symptomatic lesions, plaque enhancement diminished with increasing time after stroke onset (38.9 ± 18.2, 22.0 ± 22.8, and 5.0 ± 10.1 for acute, subacute, and chronic phase, respectively; p = 0.001). Conclusion: Plaque enhancement in the acute atherosclerotic plaque is closely related to recent ischemic events. In symptomatic atherosclerosis, plaque enhancement regresses over time after ischemic stroke, which may offer the potential to monitor the plaque activity in intracranial atherosclerosis using HRMRI.
Insights
Plaque enhancement on high-resolution MRI in middle cerebral artery (MCA) atherosclerosis is linked to recent stroke. Enhancement decreases over time in symptomatic plaques, potentially aiding monitoring of intracranial atherosclerosis activity.
Area of Science:
- Neurology
- Radiology
- Cardiovascular Science
Background:
- Contrast enhancement on high-resolution magnetic resonance imaging (HRMRI) is a key feature of intracranial atherosclerotic plaque.
- The clinical significance of plaque enhancement in middle cerebral artery (MCA) stenosis remains unclear.
Purpose of the Study:
- To quantitatively assess plaque enhancement patterns in MCA atherosclerotic plaques.
- To investigate the relationship between plaque enhancement and recent ischemic events.
Main Methods:
- A cross-sectional study involving patients with >30% MCA stenosis undergoing contrast-enhanced HRMRI.
- Patients were categorized into acute, subacute, and chronic phases based on time from stroke onset.
- Plaque enhancement index was calculated at the site of maximal narrowing.
Main Results:
- Eighty-nine MCA plaques were analyzed in 58 patients; 64% were in the acute phase.
- Symptomatic acute plaques showed significantly higher enhancement than asymptomatic ones (38.9 vs. 18.2, p < 0.001).
- Plaque enhancement in symptomatic lesions decreased significantly over time (acute, subacute, chronic: p = 0.001).
Conclusions:
- Acute plaque enhancement in MCA atherosclerosis correlates with recent ischemic events.
- Plaque enhancement diminishes over time in symptomatic cases, suggesting potential for monitoring plaque activity.
- HRMRI-based assessment of plaque enhancement may offer insights into intracranial atherosclerosis progression.
