PET-CT brain is a modern research method that allows using special radiopharmaceuticals to obtain information about the functional state of various parts of the brain. While MRI and CT are used to study the anatomical structure of brain tissue, PET-CT is used to assess its functional activity, and therefore it is called functional tomography. Thus, positron emission tomography is a qualitatively new diagnostic method, thanks to which it became possible to diagnose diseases at the earliest stage of their development – before the appearance of morphological changes.
Positron emission tomography of the brain in neurology is most often prescribed to assess such metabolic processes of brain tissue as oxygen utilization, glucose metabolism, capillary blood flow and perfusion, affinity of specific receptors and their number. The information obtained makes it possible to identify abnormalities in the vital activity of brain cells that occur at the initial stages of the disease. Due to this, many neurological pathologies are diagnosed much earlier than during CT or MRI of the brain.
In vascular diseases, PET-CT makes it possible to detect even minor hemodynamic disorders, determine the degree of their severity and prevalence, and differentiate vascular dementia from its other types. In the diagnosis of volumetric processes of the brain, PET is used for early detection of tumors, their differential diagnosis with other volumetric formations (abscess, cyst), assessment of the degree of malignancy. In addition, the technique is used to clarify the size and boundaries of neoplasias that are not clearly visualized on CT or MRI, to evaluate the results of radiological treatment and chemotherapy, and the radical removal of neoplasms.
In epilepsy, the procedure is prescribed to identify the location of the epileptic focus. Using this method, neurosurgeons determine the most significant functional areas of the brain in order to avoid their damage during surgery. Acute injuries and the post-traumatic period are indications for PET-CT in cases where CT or MRI data do not provide a complete explanation of the clinical picture available to the patient.
Since positron emission tomography is a radiation method of investigation, it is absolutely contraindicated during pregnancy. The technique is used with caution in patients with sub- and decompensated form of diabetes mellitus (blood sugar > 6.5 mmol / L), acute infections and exacerbation of chronic inflammatory diseases. In a serious condition of the patient, manipulation is not recommended because of the need to remain motionless for a long time. In the presence of relative contraindications, PET-CT brain can be performed if it is vital for the patient.
Methodology of conducting
The patient is advised not to eat for 6 hours before the study. The night before, you should refrain from a hearty dinner (it is better to have dinner with sour-milk products). The procedure is performed using tomographs resembling MRI and CT machines. Before starting the manipulation, the patient is intravenously injected with a radiopharmaceutical, which is a radionuclide-labeled chemical compound involved in the metabolism of brain cells. Glucose is usually used.
Then the patient needs to lie quietly for 30-60 minutes so that the drug has time to be distributed throughout the body. It is forbidden to move or talk, because the compound may accumulate in the working muscles, which will affect the reliability of the results. Then the patient is placed in a tomograph chamber, where special moving sensors register areas of accumulation of radiopharmaceuticals and features of its distribution. The received information is sent to the monitor in the form of functional images. Scanning lasts 30-40 minutes. After the procedure is completed, the patient is recommended to drink copious amounts to accelerate the elimination of the drug from the body. Processing of the received data can take from 2-3 hours to several days.
Complications during PET-CT are not observed. The labeled drug used during the manipulation is practically harmless and does not cause adverse reactions, since it is administered in a very small dose. The dose of X-ray irradiation does not exceed the radiation load during chest radiography.