Evaluation of extracranial carotid artery duplex ultrasound scanning parameters in cerebral ischemic or nonischemic patients without significant cervical carotid artery stenosis

Although extracranial carotid artery duplex ultrasound scanning (ECADUS) is frequently used to detect cervical carotid artery stenosis, the method for interpreting the parameters obtained by ECADUS is not well established when cervical carotid artery stenosis does not exist. We retrospectively studied the parameters obtained from 180 patients without significant cervical carotid artery stenosis. The peak systolic velocity (PSV), end diastolic velocity (EDV), pulsatility index (PI) and diameter of the cervical internal carotid artery, and intima media thickness (IMT) of the common carotid artery were obtained bilaterally. These parameters were evaluated according to the side and the patient's sex, age, and cerebral ischemic symptoms. No significant effects of the side or sex were observed on any parameters. Aging affected the IMT and PI positively and the EDV negatively. The PI correlated positively with the IMT. In the symptomatic group the PSV and EDV decreased; this was still observed after adjustments for age. These results confirm the effects of aging. PI seems to be another indicator of cerebral atherosclerosis, because it correlates well with IMT, a well-recognized indicator. Cerebral ischemic symptoms may be affected by reduced velocity more than by atherosclerotic progression. This phenomenon requires further evaluation.