Comparison of Degree of Stenosis and Plaque Volume for the Assessment of Carotid Atherosclerosis Using 2-D Ultrasound

The degree of carotid stenosis (%ST) remains the most frequently used parameter for identifying patients with high risk of stroke but the relationship between %ST and the occurrence of stroke remains controversial. The objectives of this study were to check (1) the relationship between the %ST and the plaque volume index (PVI) as measured by echography and Doppler, (2) the relationship between the intima media thickness (IMT), a vessel wall remodeling index and the PVI an atheromatous growth index. For each of the 128 patients, (165 carotid stenosis), we measured the % ST (section or diameter), the max stenosis velocity (Vmax), the PVI and the common carotid IMT. The %ST (section) ranged from 10% to 93% (mean 66 ± 18), Vmax from 0.3 m/s to 3 m/s (mean 1.2 ± 0.8), PVI from 0.61 cm3 to 1.17 cm3 (mean 0.41 ± 0.21) and the IMT from 0.08 cm up to 0.31 cm (mean 0.12 ± 0.03). There was no significant correlation between either PVI and %ST (section or diameter), PVI and minimal stenosis section area (S1) or between PVI and Vmax. There was no significant correlation between IMT and both %ST area and PVI. PVI was significantly correlated with the whole artery section area (S2) and the plaque length (L). The %ST (section or diameter) was significantly correlated with S1 but not with S2. The absence of correlation between the PVI and the %ST confirm that these two parameters describe two different processes of the atheromatous development. (E-mail: arbeille@med.univ-tours.fr)