Objective : In order to elucidate whether the elasticity of plaques evaluated using the echo tracking method is related to plaque echo density or pathological findings, we studied patients with carotid stenosis.
Methods : We carried out carotid ultrasonographic examination in 21 patients with carotid stenosis exceeding 90% in area, evaluated the echo density of the plaques, and measured the β and Ep values by echo tracking. We then compared the β and Ep values in relation to echo density. Moreover, in patients undergoing carotid endarterectomy, the β and Ep values were also compared with the pathological features of the plaque.
Results : There were12low-echoic plaques in12patients (low－echoic plaque group) and9iso－hyperechoic plaques in9patients (iso－hyperechoic plaque group). The β and Ep values in the low－echoic group were significantly lower than those in the iso－hyperechoic group ( β, 7.3 ± 2.6 vs. 14.0 ± 6.9, p < 0.005, Ep, 101.4 ± 32 vs. 200.7 ± 101, p < 0.005, respectively). Six patients underwent carotid endarterectomy. The AHA tissue type of the plaques was type VI in4cases and V in the other 2. The β and Ep values of the type VI plaques were lower than those of the type V plaques.
Conclusions : It seems that the β and Ep values evaluated by the echo tracking method are related to the echo density and tissue characteristics of plaque.
