Computer tomography of the brain: indications, contraindications and varieties
Mar 28, 2018
Computed tomography is a modern kind of X-ray study combined with computer processing of the image of the organs, systems and parts of the human body being studied.Allows you to receive an image in the specified planes.The informativity of the method is superior to all conventional X-ray studies.
He visualizes the bones of the skull, thoroughly "enlightens" the accessory sinuses of the nose, reveals the vascular pathology of the brain, provides irreplaceable help in diagnosing the consequences of head injuries.
Note : the dose of radiation during CT of the brain exceeds the levels that a person receives with the usual radiographic method, therefore computed tomography requires compulsory medical justification of its necessity.The more modern the equipment, the less the patient is exposed to radiation.
The task of this article is to describe what the computer tomography of the brain shows, describe its main varieties, the diseases determined by the technology of sharing the X-ray machine and the computer.
Indications for CTDComputed tomography without contrast agent is performed with:
- traumatic head lesions- bruises, concussions, fractures of the skull bones, hematomas;
- as a screening method in the detection of pathology;
- in dental practice for the detection of anomalies of the maxillofacial area, diagnosis before implantation;
- acute phase of cerebral circulation, to assess the degree of brain atrophy and the presence of fluid( hydrocephalus);
- frequent convulsive conditions with fainting and headaches;
- speech and swallowing disorders, facial muscles asymmetry;
- all kinds of impaired consciousness, in the case of senile dementia.
Computed tomography with the introduction of contrast in the vessels is prescribed in cases:
- suspected of an existing tumor of the brain or its membranes;
- inflammatory diseases - encephalitis, arachnoiditis, meningitis, abscesses;
- assessment of brain states after surgical treatment of tumors;Chemotherapy, irradiation.
The introduction of a contrast agent makes it possible to more clearly recognize pathological foci.
For a detailed description of the principle of examining patients using a combined X-ray machine and computer, see this video review:
Computed tomography-angiography of the brain is a study of the vascular bed in the cranial cavity.With the help of a special injector syringe, a substance is injected into the vein that can "stain" the vessels in such a way that they clearly show through the procedure.Used the ulnar or subclavian vein.Also sometimes involve the direct introduction of contrast in the artery.
The indications for this type of diagnosis are:
- suspected aneurysms of the cerebral vessels( saccule protrusions of the artery walls);
- the presence of stenosis( narrowing) of the vessels.Together with the location of this pathology, the degree of narrowing is determined;
- occlusion of the vessel - its obstruction due to the formation of a thrombus, or blockage by a moving embolus( torn off).
Angiography assesses the structure of the walls of the arteries of the brain, the magnitude of thrombotic masses and cholesterol plaques, the anatomical features of surrounding tissues, the speed of passage of contrast medium.
Computer image processing allows you to view the pathological focus in all details and create a three-dimensional image.
Contraindications to the use of computed tomography of the brain
Computed tomography is a rather complicated method and has its own limitations.
Contraindications to CT of the brain include:
- pregnancy, except in cases that endanger the life of a woman( severe injuries, acute vascular pathology, peritonitis);
- previously available allergic reactions of the patient, accompanied by itching, heart rhythm disturbances, laryngeal edema, vomiting;
- severe forms of bronchial asthma;
- complicated diabetes mellitus;
- renal and hepatic impairment;
- pathology of the thyroid gland;
- presence of mental illnesses of patients with inadequate reactions;
- excess obesity patient( over 200 kg), not allowing the technical characteristics of the device to function normally.
Note: Is the preparation of the patient necessary for the study?To prepare it is necessary only in the event that the contrast medium will be applied.Preparation is that a person is not allowed to take food and water at least 4 hours before the procedure.
How is computerized tomography of the brain
? The examination takes place on a special table, which must be taken to the patient.The table moves during the procedure with respect to the tomograph.Thin bundles of directed X-rays illuminate the investigated regions in given planes and are recorded by a special device that transmits the signal to the computer for subsequent processing.
The duration of the procedure is up to 15-20 minutes.
Spiral computed tomography of the brain( SCT)
This is the most modern X-ray examination method.During the session, not only the table with the patient moves, but also a spiral X-ray tube with circular detectors.The study makes it possible to obtain very qualitative and accurate results with a decrease in the irradiation time.In the images of SCT, there are no inherent interference with other methods created by the blood flow in the vessels.
Important: The multispiral devices developed in recent years( MSCT) have further reduced the time for diagnosis and increased the number of cuts.
Spiral computed tomography of the brain does not require preparation of the patient.
All types of modern diagnostic method - CT, SCT and MSCT of the brain - allow the doctor to obtain data that are not available for other methods of investigation.
How is computed tomography performed and what rules should be observed for the examinee?You will get the answer by watching a short video clip:
Alexander Lotin, radiologist,