CT skull is a method of high-precision tomographic X-ray diagnostics that allows visualizing the bones of the cerebral and facial skull, soft tissues of this anatomical zone. The study is performed during the diagnosis of traumatic brain injuries, fractures of the bones of the facial skull, tumors, developmental abnormalities, foreign bodies, inflammatory changes and pathological processes of other etiology. CT of cranial bones is carried out with and without contrast, does not require special training. Before contrasting, it is necessary to refuse to eat.
Indications
Radiation examination allows you to examine the bones of the cerebral and facial skull, maxillary and frontal sinuses, assess the integrity and symmetry of solid structures, identify the divergence of sutures, determine the size and shape of cavities. CT skull can be used for traumatic brain injury. The technique makes it possible to establish the presence, localization and nature of the fracture, to confirm damage to the medulla. With the help of the procedure, the causes of liquorrhea are determined with a fracture of the base of the skull, pathologies of the temporal bone with possible damage to the hearing aid, curvature of the nasal septum, localization of uncut teeth are diagnosed. The procedure is indicated for the detection of tumors of the bones of the skull and paranasal sinuses (including the germination of neoplasms from neighboring areas), metastases, polyps, cysts. The technique is prescribed to exclude multiple bone lesions in fibrotic dysplasia, which may be asymptomatic in the initial stages.
Soft-tissue structures are less visible than bones when using the method, so CT scans of the skull with contrast are sometimes used to study them. The procedure is performed for bruises, swelling of the face and neck, hematomas, inflammatory processes, tumors in soft tissues. As indications, a severe course of frontitis, sinusitis can be considered in case of suspected spread beyond the sinus with damage to soft-tissue and hard structures. In addition, scanning is performed before complex reconstructive operations in order to pre-plan the course of surgical intervention (especially plastic surgery) and in the postoperative period to evaluate the results of the operation.
Contraindications
During the scan, the patient receives a small dose of radiation, so the passage of the study according to the indications is quite safe. Pregnancy is an absolute contraindication, since X-ray radiation has a teratogenic effect and is dangerous for the fetus even in minimal doses. Tomography is not performed for children under 14 years of age. The exception is cases when during pregnancy or in childhood manipulation is performed for vital indications. There are restrictions on body weight related to the load capacity of the equipment. The presence of metal implants (for example, plates after plastic surgery of a skull bone defect) in the study area is not a contraindication, but may negatively affect the information content of the procedure. Contrast tomography is contraindicated in patients with iodine intolerance, endocrine disorders, severe kidney and liver pathology, diabetes mellitus.
Preparation
The procedure is performed on an outpatient basis (at the direction of the doctor or at the request of the patient) or during inpatient treatment. Contrast-free examination does not require preparation. Contrast CT skull is performed on an empty stomach. Before applying the contrast, a skin test is carried out, revealing the intolerance of iodine preparations. If its result is negative, the contrast is injected intravenously, a uniform distribution of the substance is expected and a scan is performed. During the introduction of contrast, there is a feeling of warmth, slight dizziness, itching, nausea may occur. The drug is excreted from the body within two days, the process accelerates copious drinking. The introduction of a contrast agent can be performed by venipuncture (simultaneously) or using an infusion system.
Methodology of conducting
Immediately before the scan, the patient removes all metal objects, puts on comfortable cotton clothes. Some clinics offer disposable underwear sets. The patient is placed on a mobile tomograph table. During the study, it is important to remain motionless, so the patient’s head is fixed with special rollers. The table moves automatically during the CT scan, and the scanner rotates around the head of the subject, taking readings. There are no unpleasant sensations during the scan. To communicate with the doctor in the next room, a two-way microphone communication is provided in the tomograph. Sometimes the patient is asked to hold his breath. The duration varies from 5 to 30 minutes, depending on the type of study (contrast or native).
The decryption of the received information is carried out on the day of manipulation, the pictures and the conclusion are given to the patient on paper. It is possible to record the results on a digital medium or send them by e-mail. After a CT scan of the skull, it is necessary to contact the attending physician who sent for the study. If a pathology is detected, a specialist can prescribe additional diagnostic techniques, determine the tactics of outpatient treatment, issue a referral for emergency or planned hospitalization.
Advantages
The advantages of the study are the ability to simultaneously examine all the structures of the skull, create three-dimensional images based on multiple scans, print out images or save them electronically. The disadvantages of the method are the use of X-rays and the accumulation of the radiation dose with a possible excess of the standards for too frequent studies (the radiation load for one procedure is 2-3 mSv, which is below the permissible norm). In addition, some patients have allergic reactions to the introduction of contrast. An alternative to CT (depending on the nature of the alleged pathology) is conventional radiography and MRI.
