CT (computed tomography) of eye and orbit
Computed tomography of the eye – the modern method of studying the state of the eyeball, retina, optic nerve and orbit. With CT it is possible to identify morphological changes of the organ, and the degree of functional disorders is estimated indirectly.
CT is indicated for the following diseases of the eye and orbit:
CT of the orbits of the eye, optic nerve and retina is the layer-by-layer x-ray scan of the patient’s body, in particular of the eyeball and orbit in various projections with computer data processing, and summation to get the final result in the form of x-ray slice of the body of the patient in the projection study. On the resulting picture you can see all of the organs, located in the projection research, in the form of a layered cut.
Almost always the CT of the retina, optic nerve and other organs the eye is done in layers – done a few cross sections, allowing to estimate the volume of the pathological process, the degree of damage and the involvement in it of adjacent organs.
Unlike conventional x-ray picture, where the picture only one plane, CT allows to obtain three-dimensional image.
No special preparation is required. Prior to the study, it is recommended to remove any metal jewelry, glasses, lenses.
The patient is placed on hardware table in the supine position. Further, the table moves inside the scanner so that the area of study were eyes. This is followed by a series of pictures that are transmitted to the monitor and recorded in the computer memory. To obtain a complete picture of the condition of the body produced a few series in certain projections. This allows to obtain slices at different levels. Radiologist prints images on paper and store on electronic media. If necessary, detailed study of it can increase the image on the monitor to the desired resolution. In some diseases may require a CT scan using contrast medium.
Duration of treatment – few minutes. When CT scan using contrast to 10-15 minutes.
Absolute contraindications no.
Pregnant women CT should be performed with caution as the possibility exists of exposure of the fetus. In advance to consult an obstetrician-gynecologist.
Study of the use of contrast agents is contraindicated if the patient has Allergy to contrast, iodine. With extreme caution, a CT scan with contrast is performed in acute kidney-liver failure, in General condition of the patient, in decompensated diabetes mellitus II, women during breast-feeding.
The advantages of the method
CT lets you see the condition of the eyeball and orbit, retina, optic nerve. Obtaining three-dimensional images of the head in the projection study provides an opportunity to assess the condition of other organs. This is of particular value in the examination of Oncology patients (allows you to define the involvement of the surrounding tissues), injuries (reveals the degree and nature of damage), when the foreign body (localization, degree of damage to the body).
Potential harms of CT are not higher than the standard radiography. No special training required. Contraindications are almost absent. Complications do not happen.
CT – noninvasive or minimally invasive (when using contrast) procedure. Many other instrumental methods of examination involve interference directly in the structure of the eyeball, which may be unpleasant or painful for the patient and fraught with complications.
Interpretation of results
The CT eye orbits you can clearly see the tumor, located vnutrigospitalina, and in the next part. When this occurs, the marginalization, displacement and change of the contours of the eyeball, optic nerve, deformity of the bones of the orbit, changes in the retina. Each type of tumor has its own morphological and histological characteristics. Previously, to determine the type of neoplasm was only possible during or after surgery. Using CT for a number of radiological signs manage to suggest the type of tumor at the stage of diagnosis. This is particularly important in the choice of tactics of treatment – conservative, surgical, laser destruction.
Exophthalmos when there is an opportunity to identify the cause of the disease – the destruction of the orbital wall, intraorbital tumor, tumor of okolonosovyh sinus.
Injuries, foreign bodies can assess the extent and severity of damage localization, the need for surgical treatment.
CT with contrast allows to study the blood supply of the eyeball and the optic nerve.
CT of the optic nerve, retina, eye orbits and other organs the eye is informative, harmless examination method, which allows the physician to obtain information that is not available when using other diagnostic methods.