mastoid

The mastoid is concealed because of its location, complex structure, and high difficulty in projection. It can be used for CT examination, especially for the examination of middle ear mastoiditis. For CT-enhanced scanning, if an ion-type contrast agent is used, an intravenous iodine allergy test is required for intravenous contrast, and no reaction can be performed after 20 minutes. Basic Information Specialist Category: Inspection Category: Other Inspections Applicable gender: whether men and women apply fasting: not fasting Tips: Inappropriate people: allergic or ionic contrast agents have a history of allergies (such as the use of ion-type contrast agents also need to do iodine allergy test), infants and elderly patients over 60 years old. Normal value The angiography was normal, the soft tissue density was uniform, the mastoid height was normal, and the small bone, bone, and upper tympanic cavity were not damaged. Clinical significance Abnormal results of simple type showed soft tissue density in different degrees in the middle ear cavity, increased mastoid density, and decreased air chamber. The type of bone ulcer is characterized by soft tissue lesions in the middle ear cavity with sigmoid sinus and part of the skull, ossicle damage, and the edge of bone destruction is unclear. The cholesteatoma type is characterized by soft tissue density in the tympanic cavity, ossicular chain destruction displacement, upper tympanic cavity, sinus sinus enlargement, external wall damage of the drum; tympanic canopy, tympanic wall, lateral semicircular canal, facial nerve canal, sigmoid sinus destruction, At the same time, the hardening ring often appears at the edge of the bone destruction cavity. Patients with ear mastoiditis who need to be examined. Precautions Taboo before inspection: 1. Before the examination, the CT doctor should be informed of the detailed medical history and various examination results. If you have your own saved X-ray film, magnetic resonance film and previous CT film, you need to submit it to CT doctor for reference. 2, remove the inspection site clothing including underwear with metal materials and various items: such as headwear, hairpins, earrings, necklaces, jade, coins, belts and keys. 3, if CT enhanced scan or children, unconscious, need to be accompanied by healthy people. 4, CT enhanced scan If you use ion contrast agent, you need to do intravenous injection of contrast agent iodine allergy test, no response after 20 minutes, before examination. 5, 1 week, do not accept drugs containing heavy metals, do not do gastrointestinal tincture examination. Patients who have been tested for expectorant need to wait for the sputum to empty; if they are eager to have a CT examination, they should be treated with a cleansing enema or oral laxative to sputum. Requirements for inspection: The inspection process should be carried out in accordance with the doctor's password. Do not arbitrarily move to ensure the clarity of the contrast. The CT machine is equipped with an intercom, and if there is any discomfort during the examination or an abnormal situation, the doctor should be informed immediately. Inspection process (1) Flat sweep: Position and range: cross-section, supine position, continuous scan to the sinus sinus with the hearing line. Coronal, prone position, continuous scan of the anterior border of the outer ear hole with the coronal line perpendicular to the sacral line. Scanning baseline: Transverse scan - listening to the sacral line (supine position); coronal scan - coronal line (prone position). Layer thickness and layer spacing: ultra-thin layer 0.5 ~ 2mm; thin layer 3 ~ 5mm. Window width and window position: soft tissue window: L30～50HU, window width: W250～300HU. Bone window: window position L250 ~ 500HU, window width: W1000 ~ 1600HU. Other requirements: high resolution algorithm. (2) Enhanced scanning: Contrast agent: non-ionic iodine-containing contrast agent, 60-100 ml for adults, and 2 ml/kg for children. Injection method: intravenous injection of high-pressure syringe, the rate of 2.0 ~ 3.0ml / s. Scanning time: Scanning starts 15 to 18 seconds after contrast injection. Scanner: The parameters are the same as the sweep. Not suitable for the crowd Inappropriate people: allergic or ionic contrast agents have a history of allergies (such as the use of ion-type contrast agents also need to do iodine allergy test), infants and elderly patients over 60 years old.

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