Objective Our aim was to investigate the difference of mechanical properties of carotid plaques in subjects with and without ischaemic cerebralvascular disease using velocity vector imaging technique.
Methods 162 carotid plaques were detected in 121 subjects. All patients were divided into three groups: patient with acute ischaemic infarction (ACI, n=48), patients with transient ischaemic attack (TIA, n=22) and patients without cerebrovascular history (NCD, n=51). With velocity vector imaging technique and syngo US Workplace (Siemens), mechanic parameters such as radial velocity (RV), longitudinal strain (LS) and longitudinal strain rate (LSR) were measured on carotid plaques at proximal base (P1), proximal shoulder (P2), top (P3), distal shoulder (P4) and distal base (P5). Morphological parameters including Intima-median thickness, plaque length and lumen diameter was also measured. Receiver operating characteristic curves were constructed from model that associate mechanical and morphological parameters.
Results Higher RV was found in TIA and ACI than that in NCD. In ACI patients, P2-LS was higher than P1-LS, P4-LS and P5-LS (p<0.05), P5-LSR was higher than P1-LSR (p<0.05). The area under the ROC curve was 0.812 in model that associate mechanical and morphological parameters. Sensitivity and specificity was 78% and 84% separately at the cut-off point.
Conclusion Measurement of mechanical parameters provides a noninvasive approach to the evaluation of plaque mechanical conditions, which is associated with ischaemic cerebralvascular disease. A characteristic of asymmetry was detected among different locations on carotid plaques especially in symptomatic subjects.