Dynamic and Interventional CT

Dynamic CT is a continuous plane scan or continuous sputum scan of a target tube in a sensitive region after rapid blood vessel injection of a contrast agent. It provides detailed information on hemodynamics and blood supply; it also effectively increases the contrast between the lesion and normal tissue. In recent years, the application of dynamic CT in liver examination is more common. Interventional CT (CT) is a new technology developed after interventional X-ray diagnosis. It is also part of interventional radiology. Although interventional ultrasound is also performed at the same time, ultrasound is greatly limited to sites containing more gas and sites with more bones such as lungs and brain. Interventional CT mainly achieves two purposes, one is CT-guided diagnosis. The second is CT-guided treatment. Common sites and organs for diagnostic purposes include needle biopsy of the brain, lung, mediastinum, liver, pancreas, kidney, adrenal gland, posterior peritoneum, pelvic mass or lymph nodes, deep muscle and osseous tissue. . Common sites and diseases for therapeutic purposes include puncture drainage and intraluminal drug injection of intracranial, thoracic, abdominal, pelvic organ hematoma or abscess, and can also be used for CT-guided percutaneous puncture to treat intervertebral disc prolapse, and achieved good results. effect. Basic Information Specialist classification: cardiovascular examination classification: microscopy Applicable gender: whether men and women apply fasting: not fasting Tips: Remove the inspection area including underwear with metal materials and various items: headwear, hair clips, earrings, necklaces, jade, coins, belts and keys. For those who need to be fasted for 4 hours before the examination. Normal value There was no abnormality in the angiography. Clinical significance Abnormal results can be diagnosed and treated by common angiography for common sites and diseases such as intracranial, thoracic, abdominal, pelvic organ hematoma or abscess. Patients in need of examination have patients with intracranial, thoracic, abdominal, pelvic organ hematoma or abscess. 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, to explain to the doctor whether there is drug allergy, whether it has asthma, urticaria and other allergic diseases. 3, remove the inspection site clothing including underwear with metal materials and various items: such as headwear, hairpins, earrings, necklaces, jade, coins, belts and keys. 4, need to enhance the person before fasting for 4 hours. 5, if CT enhanced scan or children, unconscious, need to be accompanied by healthy people. 6, CT enhanced scan If you use ion contrast agent, you need to do intravenous injection of iodine allergy test, no response after 20 minutes, before you can check. 7, do not take heavy metal drugs within 1 week, 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: 1. Obey the instructions of the technicians during the inspection, keep the position and do not move, and cooperate with the examination to calmly breathe, hold your breath, do not swallow, and do not blink your eyes. 2. The CT machine is equipped with a walkie-talkie. If there is any discomfort during the examination or an abnormal situation occurs, the doctor should be informed immediately. Inspection process 1, arterial venography CT: refers to the superior mesenteric artery catheterization, 60% iodine solution 70 ~ 100ml, 1.2 ~ 1.5 / s speed injection, from the injection of contrast agent 20 ~ 25s after the start of scanning. The contrast agent passes through the superior mesenteric artery, capillaries, superior mesenteric vein, portal vein, hepatic blood stasis, to the hepatic vein and inferior vena cava. This technique has a high detection rate for small liver cancer, which is superior to MRI, conventional CT and general delayed CT. Because the blood supply of primary or metastatic liver cancer is mostly from the hepatic artery, the normal liver parenchyma is mainly supplied by the portal vein, so the lesion on CTAP shows a low density change. According to the shape and density of lesions on CTAP, benign and malignant lesions can be distinguished. 2, continuous CT angiography scan (CCTA): refers to the injection of contrast agent through the hepatic artery for 3 seconds, after the injection of about 10 ~ 20ml of contrast dose, continuous scanning on the same level for 24 seconds, in turn by the same method layer by layer The method is said to have a sensitivity of 98% to liver metastases and a specificity of 81%, which is significantly higher than ultrasound and conventional CT scans. 3. Biphasic CT: To maintain the proper concentration of contrast agent in the scanned organ. The total amount of contrast agent is divided into two phases, and intravenous injection is performed at different speeds. The first injection speed is fast, 30~50ml contrast agent, 1.3~1.5ml/s, and CT scan is performed 20~30s after the start of injection. . The second phase of injection is slower, 50ml contrast agent, 0.5ml / s injection. Biphasic CT scan can better reflect the hemodynamic changes of the lesion and normal organs. This technique requires an automatic pressure syringe to obtain a satisfactory enhanced CT image. 4, lipiodol CT: CT scan after injection of lipiodol into the hepatic artery, lipiodol will enter the 'cancer area, a round or oval high-density mass, the positive rate can be as high as 96%, negative and cancerous In terms of less blood, in a group of 100 cases of small liver cancer, only one case of liver cancer <3.0cm in diameter showed less blood type, and there was no accumulation of iodine oil contrast agent on CT. Not suitable for the crowd Inappropriate population: patients with severe heart and kidney failure and patients who are allergic to iodine and contrast agents.

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