What Is Vascular Stenosis?

Cerebrovascular stenosis is an important cause and risk factor of ischemic cerebrovascular disease. Cerebrovascular stenosis reduces the amount of blood passing through the cerebral blood vessels, and brain cells die.

Cerebrovascular stenosis

Cerebrovascular stenosis is caused by

There are many causes of cerebral vascular stenosis, and they are related to age. For example, the age of vascular stenosis caused by nodular arteritis is 10 to 30 years old, and those with arteriosclerotic stenosis are often 40 to 80 years old, and even Older people. Children with disease are mostly caused by congenital vascular development abnormalities, and cervical spondylosis is also a predisposing factor for cerebrovascular stenosis.

Treatment of cerebral arterial stenosis includes drug therapy, surgical treatment and

There are three commonly used measurement methods of ICA stenosis rate, namely NASCET method, ECST method and CC method.

The NASCET method is the most widely used. In addition to ICA, it can also be used in vertebral-basal artery and intracranial ICA-MCA systems. The formula is: stenosis rate = (normal diameter of distal stenosis-narrowest diameter of stenosed segment) / distal stenosis Normal diameter × 100%.

The formula of the ECST method is: stenosis rate = (estimated normal diameter of the stenotic segment-narrowest diameter of the stenotic segment) / estimated normal diameter of the stenotic segment × 100%.

The formula of CC method is: stenosis rate = (diameter of common carotid artery-diameter of stenosed segment) / diameter of common carotid artery × 100%.

Asymptomatic stenosis

Symptomatic stenosis (ICA, CA stenosis> 70%, MCA, BA stenosis> 50%)

Type I stenosis: ischemia in the blood supply area of the stenoses, and clinical manifestations of ischemia in the relevant area.

Type stenosis: ischemia due to collateral blood supply area caused by stenosis (

Diagnosis is based on clinical manifestations and auxiliary examinations. Non-invasive examination: ultrasound and magnetic resonance angiography (MRA). Invasive examination: cerebral angiography.

Cerebral arterial ultrasound

Combining B-mode ultrasound imaging and transcranial Doppler examination to detect cerebral arterial stenosis. Transcranial Doppler is currently the most widely used non-invasive detection method for detecting cerebral arterial stenosis. The B-mode ultrasound scan can show the longitudinal section of the artery in real time. Doppler examination can help evaluate the blood flow of the carotid artery, and evaluate the degree of carotid stenosis based on preset parameters.

CT angiography (CTA)

Mainly understand whether the extracranial segment of the carotid system has stenosis, calcified plaque and its extent and scope. If the ultrasound examination method is not sure, CTA examination can be supplemented. CTA can accurately display the diameter of the vascular cavity. If necessary, the film is displayed under the conditions of a window width of 850HU and a window position of 200HU. Can maximize the distinction between blood vessel walls, lumens and soft tissue or calcified plaques. The comparative study of CTA before and after carotid stent implantation has advantages over MRA.

Magnetic resonance angiography

1. MRA: No contrast agent is required, and blood vessel imaging can be performed mainly by relying on the fluidity of blood. It is a non-invasive examination method. And the observation range is significantly larger than that of CTA, from the aortic arch to the intracranial cerebral blood vessels.

2. Enhanced MRI scan: The method of enhanced MRA is significantly better than conventional MRA, which is faster and more sharp. Its imaging quality is very close to that of angiography.

Cerebral angiography

Cerebral angiography is the 'gold standard' for evaluating cerebral blood vessels, but it is an invasive and non-preferred test. When B-, CTA, TCD, and MRA tests are suspected of cerebrovascular stenosis (especially intracranial cerebrovascular stenosis), catheter angiography is necessary to confirm the diagnosis. This kind of examination can dynamically and comprehensively observe the blood flow, cerebrovascular conditions, collateral compensation and the complete condition of the Willis ring.