Progressive T1 high-intensity plaques in carotid stenosis: Comparative MRI analyses in asymptomatic and symptomatic phases of low-grade stenosis

Background and Purpose

Carotid artery stenosis, particularly the progression from asymptomatic to symptomatic lesions, is a key factor in cerebrovascular events. This study identifies predictors of symptom development in low-grade carotid stenosis (<50%), focusing on intraplaque hemorrhage (IPH) and dynamic plaque changes.

Materials and Methods

We conducted a retrospective study analyzing 30 cases of symptomatic low-grade carotid stenosis, using carotid MRI before and after symptom onset. Key measures included relative plaque signal intensity (rSI) and high-intensity plaque (HI plaque) volume. Stepwise regression analysis examined the influence of these factors on Symptomatic rSI, Symptomatic plaque volume, and NIHSS scores.

Results

Significant increases were observed in rSI (1.32 ± 0.32 to 1.69 ± 0.25, p < 0.001) and HI plaque volume (296.4 ± 362.7 mm³ to 717.5 ± 554.9 mm³, p < 0.001) from asymptomatic to symptomatic phases. Past smoking (p = 0.008) and statin use (p = 0.04) were associated with higher Symptomatic rSI, while poor risk factor control (p = 0.03) was negatively associated. Female sex (p = 0.007) and current smoking (p = 0.009) were linked to smaller Symptomatic plaque volumes, while ischemic heart disease (p = 0.0002) and poor risk factor control (p = 0.002) predicted larger plaque volumes. Larger plaques were correlated with higher NIHSS scores (p = 0.002).

Conclusions

IPH and plaque volume are key markers of progression in low-grade carotid stenosis. Poor control of cardiovascular risk factors and a history of ischemic heart disease contribute to plaque burden and stroke severity. Continuous monitoring and strict risk management are essential in reducing stroke severity in these patients.