Spiral CT

Spiral CT breaks through the design of traditional CT. It uses slip ring technology to lead the X-ray tube and detector sliding brush and metal ring connecting the power cable and some signal wires to different metal rings in the fixed frame. The bulb and the detector are not limited by the length of the cable, and rotate continuously and continuously along the long axis of the human body. The scanning bed is synchronously moved at a constant speed (the conventional CT scanning bed is stationary during scanning), and the scanning trajectory is spirally advanced, which can be quickly and uninterrupted. Complete the volume scan. Basic Information Specialist Category: Inspection Category: CT Applicable gender: whether men and women apply fasting: fasting Tips: Abdominal, pelvic and enhanced scans, fasting 6 hours before the scan, check the morning fast. Normal value To quantify the tissue's absorption rate for X-rays, Hounsfield defines a new scale "CT value." The CT values ​​of different tissues vary, and each fluctuates within a certain range. The CT value of the bone is the highest, 1000HU, the CT value of soft tissue is 20~70HU, the CT value of water is 0 (±10) HU, the CT value of fat is -50~-100, and the CT value of air is -1000HU. Clinical significance 1 Volume scanning of the entire organ or a part of a breath holding, will not cause the omission of the lesion. The increase of scanning speed in 2 unit time reduces motion artifacts, improves the utilization rate of contrast agent, and saves the amount of contrast agent. Some people report that it can save about 50%. 3 can be arbitrarily, retrospective reconstruction, no layer interval size constraints and the number of reconstruction times. 4 volumetric scanning improves the quality of multi- and three-dimensional reconstructed images. Precautions Before the examination: abdominal, pelvic and enhanced scanning examination, fasting 6 hours before the scan, check the morning fasting. Remove metal objects from the part to be inspected. Such as hairpins, keys, coins and buttons containing metal substances to prevent the occurrence of counterfeit shadows. For patients who do not affect cooperation, such as infants and young children coma, sedatives must be given in advance. After the inspection: it can be completed in ten minutes, basically no discomfort. Inspection process 1. Do a good job of preparing the patient: Prepare the patient according to the requirements of different parts. Iodine allergy tests must be performed on patients who need to be augmented. Explain to the patient: Eliminate fear and make the patient cooperate with the examination. 2, the choice of scanning conditions: including body position, layer thickness and layer spacing, scanning parameters and scanning methods. Not suitable for the crowd Unsuitable people: iodine allergies, severe liver and kidney dysfunction, severe thyroid patients, acute pancreatitis, acute thrombophlebitis, multiple myeloma and other heterogeneous proteinemia, severe cachexia. Use with caution in patients with high risk factors, such as poor renal function, diabetes, asthma, urticaria, eczema, other allergic diseases, heart disease, other drug allergies, children under 1 year old and elderly over 60 years old.

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