RESUMO
Objective To explore the value of the diagnosis of middle cerebral artery (MCA) stenosis with transcranial Doppler ultrasound (TCD). Methods The clinical data in patients with ischemic cerebrovascular disease examined with digital subtract angiography (DSA)and TCD were analyzed retrospectively. DSA was used as a gold standard to analyze the sensitivity and specificity of the diagnosis of MCA stenosis with TCD. The normal and TCD blood flow velocity with different degrees of stenosis were compared. The best cut-off point of the TCD blood flow velocity of MCA at different degree of stenosis was calculated. Results DSA confirmed that 103 patients had MCA stenosis or occlusion, in which 12 were mild stenosis, 22 were moderate stenosis, 40 were severe stenosis, and 39 were occlusion. Compared to DSA, the sensitivity of TCD in detection of moderate and severe MCA stenosis or occlusion was 78. 8%, the specificity was 96. 0%, and the accuracy was 93. 0%, the missed diagnosis rate was 21. 2%, and the misdiagnosis rate was 4. 0%. As to the blood flow velocity, there was no significant difference between the mild stenosis and normal groups; while there was significant difference between the moderate stenosis and normal groups (P ＜0. 001). In addition, there was no significant difference in blood flow velocity between the moderate stenosis and severe stenosis groups. Determining the cut-off value of the best peak systolic velocity of the moderate stenosis was 163. 5 cm/s, while the best cut-off value of the mean velocity was 108. 5 cm/s. Conclusions TCD has certain advantages in the diagnosis of the MCA stenosis or occlusion, and it can be used as a safe and inexpensive screening means before DSA examination.