There are several photos in neurology. What are they tested for?

Computed tomography (CT): With the help of CT, doctors can widely detect diseases of the brain and spine.

Magnetic resonance imaging (MRI):MRI is to place the patient's head or whole body in a strong and uniform magnetic field to obtain a clear anatomical image of the patient's examined part. There is no X-ray in MRI, which is very safe. MRI is superior to CT in the diagnosis of old stroke, most brain tumors, brain stem and cerebellar diseases and multiple sclerosis. A clearer image can be obtained by intravenous contrast agent enhanced imaging. The new computer program of magnetic resonance imaging can measure the function of the brain.

Echocardiography: Echocardiography is a brain imaging examination using ultrasound. Because its examination process is simple, painless and relatively cheap, it is suitable for the examination of cerebral hemorrhage in children under 2 years old. Cases of ventricular enlargement (hydrocephalus) caused by hydrocephalus can be examined by bedside. This kind of examination has been replaced by CT or MRI in older children and adults.

Positron emission tomography (PET)

PET is an image of the internal structure and functional state of the brain obtained by displaying the distribution of special radionuclides in the body. The function of brain can be measured by transmitting radionuclide tracer to brain tissue through blood. For example, when candidates do mathematical calculations, PET can show that a certain part of the brain has the most active function, and PET is also suitable for checking epilepsy, brain tumor, stroke and so on. PET is mainly used for research.

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Single photon emission computed tomography

SPECT uses radionuclides to understand the changes of blood supply and metabolic function of brain. Once the injected or inhaled radionuclide enters the brain tissue through blood, its intensity in different parts of the brain reflects the blood supply of the brain or the function of the neurotransmitter receptor that can absorb the radionuclide. The accuracy and specificity of this technology are worse than that of PET.

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Cerebral angiography

Cerebral angiography is to inject contrast agent (visible substance under X-ray) into the blood vessels supplying cerebral blood and display the image of cerebral blood flow, so as to check abnormal cerebrovascular diseases such as aneurysm, arteritis, arteriovenous malformation and cerebral vascular occlusion. The improved MRI image can also show the blood supply of the neck and brain base, but its image is not as detailed and clear as that of cerebral angiography.

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Doppler ultrasound scanning

Doppler ultrasound scanning evaluates the risk of stroke by measuring the blood flow of carotid artery and skull base artery. Different cerebral blood flow is displayed in different colors on the monitor. The advantage of this technique is that it is painless, can be examined at the bedside, and is relatively cheap.

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Spinal myelography

Myelography is to inject contrast agent into the spinal cavity and examine the spinal cord by ct or X-ray. Myelography can detect spinal diseases, such as disc herniation or carcinomatosis. The CT scan of this technique is particularly clear. Because MRI is simple and safe, and the image is more detailed and clear, myelography is mostly replaced by MRI at present.

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electroencephalogram

EEG examination is simple and painless. Electroencephalogram (EEG) is to put 20 wires on the scalp to detect and record EEG activity. EEG recording of various waveforms is helpful to diagnose epilepsy and some rare brain metabolic diseases. For some intractable epilepsy, 24-hour recording is used. But this kind of inspection can't provide obvious specific information.