When there are symptoms of cerebrovascular, such as headache, dizziness, neurological dysfunction discomfort, how should we do the examination and what does the review include? What are the specific recommendations? When cerebrovascular disease is considered, in addition to neurological examination and blood tests, the most important element is the examination of blood vessels. The general order is to start with non-invasive examinations and then proceed with CT (ComputedTomography), which is an electronic computed tomography scan. It uses precisely collimated X-ray beams, gamma rays, ultrasound, etc., together with a highly sensitive detector to scan around a part of the human body in one section after another, which has the characteristics of fast scanning time and clear images. It is recommended for CT examination of cerebrovascular disease.
How much do you know about cranial CT examination?
1.CT is the first choice for cerebral hemorrhage.
2.CT is the first choice of diagnostic test for arachnoid hemorrhage.
3.CT is the first choice of emergency examination for acute ischemic stroke.
4.NECT should be completed to exclude cerebral hemorrhage and to clarify the presence of hypointense ischemic foci before intravenous rtPA treatment.
5, CT can be used as the initial routine examination for cerebral venous sinus thrombosis; if unexplained edema or cerebral hemorrhage is found in the cerebral cortex and subcortical areas, the possibility of thrombosis should be considered, but at this time, due to the low sensitivity and false positive rate of CT, it is not recommended as the first choice.
What do you know about cranial MRI?
Magnetic resonance imaging is a type of tomographic imaging that uses magnetic resonance phenomena to obtain electromagnetic signals from the body and reconstruct information about the body. Both cranial MRI and cranial CT are commonly used to examine brain diseases. Recommended MRI examinations for cerebrovascular disease.
1. Within 6 hours of the onset of stroke symptoms, diffusion-weighted imaging (DWI) has better sensitivity and specificity than CT and other MRI examination modalities, and is useful for early ischemic stroke diagnosis.
2. If the patient has symptoms for more than 3 hours, it is recommended to improve MRI-DWI or CTA-SI, angiography and perfusion imaging, which is especially important for patients with arterial thrombolysis or embolization.
DWI can assess the severity of stroke in the anterior part of the brain and the final infarct size, but it is not recommended to perform this test in the basal region.
MRI-DWI is useful for predicting the final infarct size and clinical prognosis.
5. MRI is significantly better than CT for the subacute and chronic phases of stroke and post-ischemic hemorrhage.
6.GRE sequence of MRI can diagnose cerebral hemorrhage at an early stage, and it is also significantly better than CT in diagnosing new or old microhemorrhagic foci.
7. For microhemorrhagic foci detected by MRI but not shown by CT, they are not contraindicated for intravenous thrombolysis at present.
What do you know about carotid ultrasound?
It mainly examines the carotid vessels (carotid artery, vertebral artery and subclavian artery) for atherosclerosis and stenosis, as well as the condition of plaque (soft plaque and hard plaque); at the same time, it can detect aneurysm and arterial entrapment. Carotid ultrasound is the most sensitive method of choice for detecting plaque in the carotid vessels. With the advantages of non-invasive, easy and safe, carotid ultrasound can clearly show whether there is thickening of the intima, whether there is plaque formation, the site and size of plaque formation, whether there is stenosis and the degree of stenosis, and whether there is occlusion. Carotid artery ultrasound examination is important for discovering whether there is plaque in blood vessels and whether there is stenosis. Through carotid ultrasound, doctors can evaluate and analyze the condition of plaque and give professional advice.
What do you know about cranial TCD examination?
Transcranial Doppler for short (TCD) is a non-invasive vascular disease examination method that uses the ultrasound Doppler effect to detect the hemodynamics of each major artery and each physiological parameter of blood flow on the arterial ring of the base of the brain within the skull. It is a direct observation of the flow status of intracranial vessels, which has been rapidly developed at home and abroad in recent years and has become one of the important tools for the diagnosis of cerebrovascular diseases at present. In the clinical application of TCD, the diagnosis of intracranial arterial stenosis is one of its most important contributions, and it is mainly used to indirectly determine the degree of stenosis of blood vessels through the measurement of blood flow velocity. Most importantly, it is a functional judgment, with anatomical lesion suggestive value, but it does not accurately infer the lesion from it, and the examination is somewhat subjective.
What do I know about CTA?
CTA is a non-invasive vascular imaging technique, the basic principle of which is to use multi-layer spiral CT to scan the target vessel at multiple levels in rapid succession after intravenous injection of contrast agent at the peak of contrast filling, and to display the target vessel structure after three-dimensional reconstruction. In conclusion, CTA is safe, convenient, rapid, qualitative and clearly localized for the diagnosis of cerebrovascular lesions, and can be used as a method for screening cerebrovascular lesions such as cerebral aneurysms and cerebrovascular malformations.
Although CTA is non-invasive, because it is an intravascular injection of a contrast agent, some people may have some adverse reactions to the contrast agent under certain circumstances, including allergic reactions and neurotoxicity, vascular toxicity, nephrotoxicity, etc., but the risk is generally low.
How much do I know about MRA exams?
Magnetic resonance MRA is based on saturation effect, inflow enhancement effect, and flow dephasing effect to show blood vessels, which can detect the site of stenosis and occlusion, as well as vascular lesions (aneurysm for, arterial malformation, etc.). It includes direct MRA and CE-MRA, both of which have their own advantages. Direct MRA is simple, non-invasive, low-cost, and has become an indispensable clinical examination method because it does not use contrast agents, and CE-MR is more reliable than direct MRA in showing the lumen of blood vessels.
As with CTA, MRA is a good visualization of the arterial phase of the cerebral vessels, while CTV and MRV are better for the venous phase.
What do I know about digital subtraction angiography (DSA)?
Digital subtraction angiography (DSA) is a computer-assisted angiographic method that uses a computer program to perform two imaging sessions. The first imaging is performed before the contrast is injected, and the images are converted to digital signals and stored using a computer. After the contrast is injected, the image is imaged again and converted to a digital signal. The two digital times are subtracted to eliminate the same signal and a contrast-only image of the blood vessels is obtained.
This image is clearer and more intuitive than the conventional cerebral angiography used in the past, and some fine vascular structures can be visualized. It can clearly observe the size of the aneurysm, the width of the aneurysm neck and the relationship with the aneurysm-carrying artery; it can clearly observe the size and shape of the cerebral arteriovenous malformation, the blood supplying artery and the draining vein; it can clearly observe the narrowing or occlusion of the cerebral blood vessels, the shape and the hard and soft ectoplasm of the vessel wall. Cerebral angiography is one of the most effective methods to examine cerebrovascular disease and has become the “gold standard” for diagnosing cerebrovascular disease. Compared with the previous tests, its biggest shortcoming is its invasiveness. When other tests reveal suspicious lesions, DSA is necessary.