Application Value Of Transcranial Color-coded Duplex Sonography On The Diagnosis Of Cerebral Artery Stenosis

Objective 1 To evaluate the character of color Doppler and frequency spectrum Doppler of cerebral artery stenosis by examining the patients who were suspected with cerebrovascular disease with TCCS.2 To evaluate diagnostic value of TCCS on the cerebral artery stenosis from comparing with DSA.3 To evaluate the effectiveness of TCCS as a useful rechecking method after the interventional therapy by rechecking patients who accepeted the interventional therapy with TCCS.Methods Patients who were suspected with cerebrovascular disease were involved in the study. The MCA, ACA and PCA were detected through the temporal window; the intracal segment of VA and the BA were detected through the pulvinar window.1 Displayed the major cerebral artery and observed the course and the shape by CDFI.2 Observed the shape of the frequency spectrum and measured each hemodynamics parameter, then compared with the normal value and analyzed the character of the frequency spectrum. All the results from TCCS were compared with DSA, and investigated the value of TCCS on the diagnosis of the cerebral artery stenosis.3 Rechecked a few patients who accepted the interventional therapy with TCCS. Observed the color flow of the stenotic vascular before the therapy, measured the hemodynamics and compared with the data before the therapy.Results 1 The sonogram character of cerebral artery stenosis: the characters imaging of CDFI was that the blood flow beam became narrow where the artery was stenosis and looked like girdling. The color of the foci became bright or inverted. The character of frequency spectrum was that the velocity of the foci increased abnormally, meanwhile the velocity before and after the foci decreased. The severe stenosis and the long stenotic segement may show discontinuity of the blood flow beam. The velocity of the foci did not increase or decrease obviously. The blood flow beam of the occlusive artery can not be seen and we can not get the frequency spectrum on condition that the other artery was visualized well.2 The analysis of the diagnostic value of TCCS according to fourfold table: the validity index, including the sensitivity, specificity, false positive rate, false negative rate, accuracy, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio, and Youden's index, were 75.0%, 81.6%, 18.4%, 25.0%, 78.6%, 77.4%, 79.5%, 4.1, 0.3 and 0.57 respectively. The reliability index, including the agreement rate and Kappa value, were 78.6% and 0.57 respectively.3 Six patients who accepted the interventional therapy were rechecked with TCCS. CDFI showed that all the stenostic vascular before the therapy were visualized well. The velocity of one measured by the PWD increased after the operation, and the others decreased.Conclusions 1 According to the change of the hemodynamics and shape of the PWD, we can suggest the preliminary diagnosis of the cerebral artery stenosis together with the CDFI.2 TCCS is of value on the diagnosis of the cerebral artery stenosis and can be considered as a diagnostic method of early screening by comparing with the DSA.3 TCCS can be a useful rechecking method after the intervention therapy.4 Because of the limitation of acoustic window and the influence of many factors, such as the attenuation of sound introduced by the crinial bone, there are some limitations to the diagnosis of the cerebral artery stenosis with TCCS.