Computer-assisted carotid plaque analysis: characteristics of plaques associated with cerebrovascular symptoms and cerebral infarction.

OBJECTIVE to correlate the echostructural characteristics of carotid plaques with neurological symptoms and cerebral infarcts. MATERIALS one hundred and five plaques were studied in 74 patients by colour-flow duplex ultrasound: 39 were symptomatic and 37 were associated with brain infarction on CT scanning. METHODS the images were digitalised for computer-assisted image standardisation and divided in homogenous (n=67) and heterogenous (n=38) groups. Parameters of the plaque image were analysed. RESULTS global echogenicity was significantly lower in symptomatic and in CT(+)plaques (p<0.05). For homogenous plaques, an echogenic cap (EC) was visualised in 8.3% of symptomatic vs. 33.9% of asymptomatic (p<0. 05) and in 7.7% for plaques that were CT(+)vs. 37.7% for CT(-)(p<0. 05). Surface disruption was visualised in 50% of symptomatic vs. 8. 5% of asymptomatic (p=0.002) and in 46% of CT(+)vs. 9.4% of CT(-)plaques (p=0.002). For heterogenous plaques, the echolucent region was juxtaluminal in 67% of symptomatic and CT(+)plaques vs. 33% in asymptomatic and CT(-)(p<0.01). CONCLUSION echolucent plaques are associated with a higher neurological risk. In homogenous plaques the absence of an echogenic cap and disruption of the plaque surface also correlates with symptoms. In heterogenous plaques, juxtaluminal location of the echolucent region is an additional marker of increased risk.