Association between carotid plaque composition assessed by multidetector computed tomography and cerebral embolism after carotid stenting.

Background: We aimed to assess the relationship between atherosclerotic carotid plaque composition analyzed using multidetector computed tomography (MDCT) and the appearance of new ischemic lesions detected by diffusion-weighted images (DWI) after carotid artery stenting (CAS).

Methods: We quantitatively and qualitatively analyzed plaque characteristics in carotid arteries using MDCT before CAS in 19 patients. Carotid plaques were expediently subdivided into four components with Hounsfield unit (HU) values of <0, 0-60, 60-130, and >600. The incidence of distal embolism was evaluated with DWI. Pearson's correlation analyses were used to assess the association between plaque composition and the incidence of cerebral embolization.

Results: Fifteen patients (79%) demonstrated new DWI lesions after CAS. High-signal DWIs were noted as follows: one in six patients, 2 ~ 5 in five patients, 6 ~ 10 in two patients, and >10 in two patients. The mean volumes of the plaque components for HU < 0, 0-60, 60-130, and >600 were 5.4, 200, 260, and 59 mm(3), respectively. There was a strong correlation between the number of high-signal DWI lesions in the ipsilateral side and the plaque volume of HU < 0 (r = 0.927; P < 0.0001). There was a moderate correlation between the number of high-signal DWI lesions and the plaque volume of HU 0-60 (r = 0.568; P = 0.0099) and the sum total of HU < 0 and HU 0-60 (r = 0.609; P = 0.0047).

Conclusions: Quantitative and qualitative tissue characterization of carotid plaques using MDCT might be a useful predictor for silent ischemic lesions after CAS.