| Objectives Intracranial arterial stenosis or occlusion caused by atherosclerosis plays an important role in the causes of ischemic stroke. Patients with acute cerebral vascular or neck intracranial stenosis occupy about 80% and among which intracranial atherosclerotic stenosis is an important cause of stroke in Asian patients. Middle cerebral artery (MCA) is currently the most studied mechanism of stroke caused by intracranial artery stenosis. The mechanism leading to cerebral infarction includes:â‘ formation of primary thrombusâ‘¡artery to artery embolismâ‘¢low perfusion caused by blood flow dynamicsâ‘£the joint action of low perfusion and artery to artery embolism. Early detection and timely treatment of intracranial arterial stenosis can reduce the incidence of cerebrovascular disease. Therefore, diagnosis by imaging methods and accurate assessment of intracranial artery stenosis is essential in guiding clinical treatment.Now, the commonly used methods in clinical detection of intracranial arteries comprises transcranial Doppler method (TCD), magnetic resonance angiography (MRA), CT angiography (CTA), digital subtraction angiography (DSA) and so on. DSA is the golden standard of diagnosis of intracranial artery stenosis or occlusion, but because of its invasive, time-consuming, expensive characteristics and other shortcomings, it is considered the most vulnerable to disability and the most expensive examination of medical complications. So it is still not the routine examination of screening for intracranial arterial stenosis. TCD is easy to operate, non-invasive, no radiation, repeatable, low cost, and can conduct real-time monitoring of cerebral blood flow. Having the incomparable advantage of other detection methods, it is of significant value for the diagnosis of brain disease, treatment and prognosis assessment.There are a number of previous evaluations of domestic and international middle cerebral artery stenosis TCD diagnosis of clinical value, but most is based on MRA or CTA as the gold standard. Taking DSA as the golden standard is relatively small, the sample less and representativeness is not strong. The purpose of this research is to explore the clinical value of TCD in the diagnosis of cerebral artery stenosis taking DSA as the golden standard.Methods A retrospective analysis of 506 cases with ischemic cerebrovascular disease diagnosed by DSA from July 2006 to October 2009 at Neurology Department of Xijing Hospital, the Fourth Military Medical University. All patients underwent DSA and TCD examination, among which 103 are with middle cerebral artery stenosis or occlusion. Taking DSA as the golden standard analyzes the sensitivity and specificity of cerebral artery stenosis diagnosis by TCD and different degree of stenosis of TCD flow velocity were compared. Also take DSA as the golden standard when calculate the best cut-off point of blood flow velocity with different degree of MCA. The control group comprises 96 cases of neurological inpatients with normal cranial blood vessels determined by DSA examination at the same period.Results The sensitivity of TCD detection of cerebral artery stenosis or occlusion was 67%, the specificity 96% and accuracy 90%, while misdiagnosis rate was 33% and misdiagnosis rate 4%. As to the blood flow velocity, there was no statistical significance between slight stenosis and normal group; moderate stenosis and severe stenosis group, while there was statistical significance between the moderate stenosis and the normal group.Conclusion TCD can not only diagnose MCA stenosis by hemodynamic change, but can also track changes in blood flow velocity in patients with MCA stenosis to observe the process of arterial stenosis, guide treatment, prevent stroke recurrence, reduce stroke incidence, disability and mortality, so as to the early discovery, diagnosis and treatment of ischemic cerebrovascular diseases. TCD can be used as a safe and inexpensive screening method before cerebral angiography.
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