Study To Diagnosis Of Posterior Circulation Ischemia Through TCD Veiocity And Puisatility Index

Purpose: Analysis of transcranial Doppler ultrasound(TCD) on intracranial posterior circulation artery and improve diagnostic sensitivity with the application of optical experiment and PI during the diagnosis of sensitivity and specificity.Method: I have collected 230 cases of posterior circulation ischemia patients which have confirmed 108 patients of posterior circulation infarction lesions and 122 patients of TIA cases in Tianjin Huan Hu Hospital by head MRI which may explain the clinical symptoms of PCI, signs of blood circulation area responsibility lesions from Jun, 2013 to Dec, 2014. All patients have been examined through TCD in one week and have also been examined 3D-CTA in CT room. Through TIA group, 7 patients cannot accept CTA examination, 9 meet with TCD acoustic window sound bad, while through myocardial infarction group, 5 patients are intolerant of CTA examination and 11 encounter TCD acoustic window sound bad. In other 198 cases, 134 cases were male, 64 were female; among aged between 29-88 years old, the average age was 60.66± 8.62 years. In the experiment of light, normal group of 80 patients, 46 patients with unilateral abnormal group.I have also used the calculation value of χ2 to test patients with vascular stenosis of intracranial circulation. With the comparison between TCD and CTA in the detection of intracranial posterior circulation vascular stenosis, I have set infarction group as an example and calculated the sensitivity, specificity, positive predictive value, vascular examination negative predictive value, accuracy and Kappa value respectively. The change rate of proximal and distal PI was used as the assistant index of the stenosis degree and F test was carried out. In the experiment of light, compared to the normal group and unilateral abnormal group, the velocity of PCA and PI on both sides of change and t test.Result: Among 198 patients, there are 92 cases accounted for infarction group and 106 cases accounted for TIA group. CTA no abnormal vascular infarction group was 106(26.3%), mild stenosis 34(8.44%), moderate stenosis 148(36.72%), severe stenosis 82(20.35%), occlusion was 33(8.19%); in group TIA, no abnormal blood vessels 265(30.67%), mild stenosis 51(9.48%), moderate stenosis was 130(24.16%), severe stenosis 73(13.57%) and occlusion was 19(3.53%). TCD no abnormal vascular infarction group was 118(32.51%), mild stenosis 24(6.61%), moderate stenosis 124(34.16%), severe stenosis 72(15.43%), occlusion was 25(3.86%); in group TIA, no abnormal blood vessels 281(57.70%), mild stenosis 34(6.98%), moderate stenosis was 102(20.94%), severe stenosis 56(11.49%) and occlusion was 14(2.87%). The twogroups had no statistically significant differences between the CTA and TCD examination. TCD for no abnormal vascular coincidence rate was 92.98%, mild stenosis of the coincidence rate was 68.20%, moderate stenosis of the coincidence rate was 81.30%, severe stenosis of the coincidence rate was 82.60% and the coincidence rate was 75.00% block. Set infarction group as an example, according to the diagnostic criteria of CTA stenosis, TCD shows no statistically different significance through the diagnosis between VA, BA and PCA. When it goes to the rate of intracranial segment of vertebral artery, its sensitivity arises to 85.71%, its specificity 90.06% and its accuracy 88.59%. The rate of sensitivity of basilar artery goes to 83.93%, specificity 86.11% and accuracy 84.78%. The rate of sensitivity of posterior cerebral artery is 68.18%, specificity 93.75% and accuracy 81.52%. The rate of sensitivity of posterior inferior cerebellar artery is 54.69%, specificity 89.17% and accuracy 77.17%. With CTA as the diagnostic criteria of stenosis, The proximal-distal ratio of PI, no significant difference between no abnormal vascular and mild stenosis. The others were statistically significant.The light in the experiment, no significant difference between the normal group about contrast, unilateral abnormal group on both sides of comparative differences were statistically significant.Conclusion: For the diagnosis of intracranial artery stenosis after circulation, TCD and CTA showed good consistency, while specificity of diagnosis of TCD is relatively high and higher than sensitivity which achieves the highest diagnostic accuracy of intracranial segment of vertebral artery. In the case of different vascular lesions, TCD for abnormal and CTA severe stenosis-diagnosis and the coincidence rate is high which is also the lowest rate of mild stenosis. The PI value can be used to judge the auxiliary index of vascular stenosis, improve the sensitivity of TCD for diagnosis of intracranial posterior circulation arteries. The light in the experiment can be used as an auxiliary means of TCD diagnosis of posterior cerebral artery disease.TCD, as a method of narrow examination to noninvasive screening of intracranial artery, with its advantage of easy control and low price, can be helpful to quantify analysis to hemodynamics, repeat exams and real-time detected of the lesions, thus can be the early methods of screening intracranial arterial lesions.