What does a CT scan of the temporal bones show?
Ultrathin sections show the integrity of the chain of auditory ossicles, destruction of the walls due to cholesteatoma, sclerosis of the mastoid process, foci of otosclerosis, anomalies of the inner ear, the course of the facial nerve canal, and fractures of the pyramid due to trauma. Based on these data, the ENT surgeon plans the scope of the operation and assesses the risks. If an acoustic neuroma or pathology of the inner ear is suspected, the examination is supplemented with MRI. No preparation required, 5-10 minutes.
Indications
- traumatic brain injury, suspected skull fracture, hematoma;
- acute cerebrovascular accident (stroke) - the first hours;
- headache with alarming signs, convulsions, impaired consciousness;
- chronic sinusitis, polyps, preparation for sinus surgery;
- hearing loss, otitis media, cholesteatoma, preparation for otological operations;
- tumors and anomalies of the bones of the facial skeleton, implantation planning.
What is MSCT
Multislice computed tomography is a layer-by-layer X-ray study in which detectors receive dozens of sections up to 0.5–1 mm thick in one revolution of the tube, and a computer builds a three-dimensional image of the organ. MSCT is performed in 5-15 minutes, accurately shows bones, lungs, stones, hemorrhages, tumors and vessels (with contrast), and is often the method of choice for trauma and acute conditions when MRI is too long or contraindicated.
Preparation and contrast
Non-contrast MSCT does not require preparation. Before a study with intravenous contrast, a test for creatinine (kidney function) and the absence of an allergy to iodine are required; 4–6 hours without eating; When taking metformin, agree on a break with your doctor. Contrast (Unigexol) is administered using an automatic injector; a feeling of warmth for 1–2 minutes is normal. To examine the abdominal and pelvic organs, oral contrast is used, which is drunk 30–60 minutes before the scan. Remove metal objects from the examination area. The radiologist’s conclusion is completed within 1–2 hours, the images are issued on film and disk.
Radiation exposure and safety
Modern devices use low-dose protocols; the dose for one study is comparable to several months of natural background and does not accumulate dangerously when prescribed appropriately. MSCT is not performed on pregnant women (except for vital indications); for children - according to strict indications with a minimum dose. Iodine contrast is contraindicated in severe renal failure, iodine allergy and uncontrolled hyperthyroidism. Pacemaker and metal implants are not a contraindication, unlike MRI.
