AIM:To assess neovascularization within human ca-rotid atherosclerotic soft plaques in patients with isch-emic stroke.METHODS:Eighty-one patients with ischemic stroke and 95 patients without stroke who had soft athero-sclerotic plaques in the internal carotid artery were studied.The thickest soft plaque in each patient was examined using contrast-enhanced ultrasound.Time-intensity curves were collected from 5 s to 3 min after contrast injection.The neovascularization within the plaques in the internal carotid artery was evaluated using the ACQ software built into the scanner by 2 of the experienced investigators who were blinded to the clinical history of the patients.RESULTS:Ischemic stroke was present in 7 of 33 patients(21%) with grade Ⅰ plaque,in 14 of 51 pa-tients(28%) with grade Ⅱ plaque,in 26 of 43 patients(61%) with grade Ⅲ plaque,and in 34 of 49 patients(69%) with grade Ⅳ plaque(P < 0.001 comparing grade Ⅳ plaque with grade I plaque and with grade Ⅱ plaque and P = 0.001 comparing grade Ⅲ plaque with grade Ⅰ plaque and with grade Ⅱ plaque).Analysis of the time intensity curves revealed that patients with ischemic stroke had a significantly higher intensity of enhancement(IE) than those without ischemic stroke(P < 0.01).The wash-in time(WT) of plaque was signifi-cantly shorter in stroke patients(P < 0.05).The sensi-tivity and specificity for IE in the plaque were 82% and 80%,respectively,and for WT were 68% and 74%,respectively.There was no significant difference in the peak intensity or time to peak between the 2 groups.CONCLUSION:This study shows that the higher the grade of plaque enhancement,the higher the risk of ischemic stroke.The data suggest that the presence of neovascularization is a marker for unstable plaque. AIM: To assess neovascularization within human ca-rotid atherosclerotic soft plaques in patients with isch-emic stroke. METHODS: Eighty-one patients with ischemic stroke and 95 patients without stroke who had soft athero-sclerotic plaques in the internal carotid artery were studied. The thickest soft plaque in each patient was examined using contrast-enhanced ultrasound. Time-intensity curves were collected from 5 s to 3 min after contrast injection. The neovascularization within the plaques in the internal carotid artery was evaluated using the ACQ software built into the scanner by 2 of the experienced investigators who were blinded to the clinical history of the patients .RESULTS: Ischemic stroke was present in 7 of 33 patients (21%) with grade Ⅰ plaque, in 14 of 51 pa-tients (28%) with Grade Ⅱ plaque, in 26 of 43 patients (61%) with grade Ⅲ plaque, and in 34 of 49 patients (69%) with grade Ⅳ plaque (P <0.001 comparing grade Ⅳ plaque with grade I plaque and with grade Ⅱ plaque and P = 0.001 vs. grade Ⅲ plaque with grade Ⅰ plaque and with grade Ⅱ plaque). Analysis of the time intensity curves revealed that patients with ischemic stroke had a significantly higher intensity of enhancement (IE) than those without ischemic stroke (P <0.01). Wash-in time (WT) of plaque was signifi-cantly shorter in stroke patients (P <0.05). The sensi- tivity and specificity for IE in the plaque were 82% and 80%, respectively, and for WT were 68% and 74%, respectively. There was no significant difference in the peak intensity or time to peak between the 2 groups. CONCLUSION: This study shows that the higher the grade of plaque enhancement, the higher the risk of ischemic stroke. The data suggest that the presence of neovascularization is a marker for unstable plaque.