A brain CT scan that shows the preparation, conduct
Most informative in the study of the brain are considered to be methods of layer-by-layer scanning with subsequent image reconstruction. Computed tomography of the brain carried out using x-ray: scanning the body of the patient involves obtaining a large number of layer images, which are then processed by a computer program. The accuracy depends on how many shots and how a gap receives the device in the course of the study.
Using x-ray computer tomography is impossible to obtain the same information as when conducting, for example, MRI, but this study is cheaper and is much faster. Therefore, if time is limited, often prescribed. If the study is necessary to control the dynamics and make it will often, CT is not the right method.
- Signs liquore-hypertensive syndrome: shows the volume and configuration of the ventricles of the brain, gives an idea about the type and causes of hydrocephalus.
Computed tomography is the ideal method of investigation in head injuries and acute disorders of cerebral circulation. Using this method you can get the necessary information quickly and without unnecessary financial costs.
In some cases, imaging of the brain junk?
Contraindications to CT scan associated with potential harm from exposure to ionizing radiation and the technical capabilities of the device. CT is desirable to conduct:
- In children, if it is possible to obtain the same information using other methods of diagnosis. Radiation exposure during CT of the brain is quite high, so the purpose of this study should be justified.
- For patients who undergo radiation therapy for malignant tumors. This requires careful calculation of the total annual radiation dose will depend on whether and how many times you can make a survey. The threshold level is a contraindication to CT.
- Pregnant women, especially during the first trimester, the study is contraindicated. II and III trimester is a relative contraindication, CT can be carried out in exceptional cases for health reasons. It is better to use MRI.
- In the presence of a claustrophobic study without the use of sedatives or anaesthesia is not possible, if necessary do a CT scan with anesthesia.
- When the patient’s weight over 150 kg study because the device is not designed for this load.
- Patients with kidney disease, diabetes and other chronic diseases in decompensation and also with a known Allergy to iodine-containing drugs, CT scans with contrast are not possible.
Computed tomography is not suitable for:
- state monitoring of tumor dynamics, in this case it would have to do too often, and radiation exposure would exceed the permissible level;
- diagnosis of demyelinating diseases of the Central nervous system and metabolic disorders;
- preparation for routine operations on the brain when it is important to determine not only the localization of the lesion, but also the location of pathways and other important functional relationship formations.
Computed tomography with intravenous contrasting
CT diagnosis of brain gives the ability to detect volume concentrations of liquid: you can see the hematoma or aneurysm of large size. But to fully visualize the vascular network is impossible, since the degree of rentgenoprosracne tissue and small vessels is about the same. Intravascular introduction of a contrast agent solves this problem. CT with contrast gives a complete picture about the state of the circulatory system of the brain and can detect the smallest defects. However, this procedure increases not only the informativeness of the study, but the level of associated risks. If the possible negative effect of the use of standard techniques of CT is limited by the action of ionizing radiation, the administration of iodinated contrast may be accompanied by severe allergic reactions, impaired renal function. Why expose the patient to the dangers of excess, if the same information can be obtained with MRI without application of contrast?
The use of contrast not only improves the informative value of CT, but also the risk of related complications and the cost of the study. In this case, it is advisable to discuss with your doctor the possibility of MRI
To reduce the risk, doctors prefer non-ionic or ionic isoosmolar means that do not alter the properties of the peripheral blood. A contrast agent when performing computed tomography of the brain with increased intravenously. While there may be a number of side reactions: itching, sneezing and coughing, headache, nausea, vomiting, and symptoms of allergic reactions of varying severity. Patients who have mounted an allergic reaction to the iodine contrast is not introduced or, if absolutely necessary, used after a preliminary introduction of antihistamines and corticosteroids. Pregnant women and patients with kidney disease, such a study is not carried out.
Prepare and conduct computed tomography
Special preparation for CT scan of the brain is not required, so this method is ideal for diagnosis of diseases requiring emergency care. Before the introduction of contrast it is advisable to refrain from eating and drinking for 4 hours. All removable metal objects: jewelry, hairpins, hearing AIDS, dentures need to be removed as they are due to the high rentgencontrastnoe can cause interference on the finished picture.
The patient is placed on the sliding bed of the scanner, which moves inside the tunnel of the machine. All x-ray computed tomography, in contrast to the devices for MRI have a closed contour, it is connected with technical features. The scan is accompanied by a slight noise in the process of the study daybed can additionally be moved. The patient should keep perfectly still during the whole time of the study, otherwise the results will be inaccurate. The process of reading information lasts no more than 15-20 minutes, followed by a stage of computer processing.
Obtained during the scanning data are then digitized and are used by the program for plotting a three-dimensional image. The radiologist performs a snapshot, which is not a diagnostic conclusion, and is addressed primarily to the doctor, not the patient. In addition, you get disk full of information and a series of main sections, printed on x-ray film.