Electron beam CT

Electron beam CT is also called ultra-fast CT. It uses the electron beam to penetrate the human body and the rapid bed movement to complete the scan. Its fastest scanning speed is 50ms/layer. Overall, it is superior to spiral CT scans. The main reason is that the scanning range per unit time is larger than that of the spiral CT, and the movement produces fewer artifacts than the helical scan. 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. Basic Information Specialist Category: Inspection Category: CT Applicable gender: whether men and women apply fasting: not fasting Reminder: Follow the instructions of the technical staff, keep the position, and check the calm breathing and breath holding. 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 CT examination has a wide range of applications and advantages, but there are still limits. The most important thing is that the sensitivity of the lesion detection is high and the specificity is still not high. Although the chest examination can be found, the hidden X-ray film can not be found. Sexual lesions, but the distinction between benign and malignant lesions of the lungs is still very difficult; the qualitative nature of abdominal lesions also has many problems. In particular, the cost of CT examination is high, and it is difficult to screen for early tumors. It is generally believed that CT, B-ultrasound, conventional X-ray, radionuclide scanning, and MRI are complementary and complementary, and the final qualitative diagnosis still needs cytology. an examination. Precautions Before the test: The patient must carry relevant examination data, including CT, MRI and routine X-ray examination data, as well as other clinical examination data. At the time of inspection: follow the instructions of the technicians, keep the position and do not move, and cooperate with the examination to calmly breathe and hold your breath. 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: severe liver and kidney dysfunction, severe thyroid disease, acute pancreatitis; acute thrombophlebitis; multiple myeloma and other heterogeneous proteinemia, severe cachexia.