Characterization of Carotid Plaque Components by Quantitative Susceptibility Mapping
M Azuma1, K Maekawa2, A Yamashita2
1From the Departments of Radiology (M.A., Z.A.K., T.H.) minako_azuma@med.miyazaki-u.ac.jp.
AJNR. American Journal of Neuroradiology
|December 28, 2019
Summary
Quantitative susceptibility mapping (QSM) can identify intraplaque hemorrhage and iron deposits in carotid artery plaques. This technique aids in characterizing plaque composition and quantifying hemorrhage severity, crucial for assessing cerebrovascular ischemic event risk.
Area of Science:
- Neuroimaging
- Cardiovascular Imaging
- Medical Physics
Background:
- Intraplaque hemorrhage in carotid arteries increases cerebrovascular ischemic event risk.
- Accurate characterization of plaque components is essential for risk stratification.
Purpose of the Study:
- To evaluate quantitative susceptibility mapping (QSM) for characterizing carotid artery plaque components.
- To assess QSM's ability to quantify the severity of intraplaque hemorrhage.
Main Methods:
- Ex vivo imaging of 9 carotid endarterectomy specimens using 3T MRI and a 3D multi-echo gradient-echo sequence.
- Histological analysis with immunostains (glycophorin A, Prussian blue) for erythrocytes and iron deposits.
- Comparison of histological findings with QSM susceptibility values.
Main Results:
- Intraplaque hemorrhage and iron deposits correlated with hyperintense QSM areas.
- Distinct mean susceptibility values were observed for different plaque components, including hemorrhage, iron, calcification, and fibrous matrix (P < .01).
- Plaque QSM values positively correlated with glycophorin A and Prussian blue staining (P < .001).
Conclusions:
- QSM effectively characterizes carotid plaque composition.
- QSM can quantify the extent of intraplaque hemorrhage and iron deposits.
- QSM holds potential for assessing cerebrovascular ischemic event risk related to plaque hemorrhage.
