Contrast-enhanced CT scan

CT contrast-enhanced scanning is a method of intravenous injection of a dose of iodine-containing water-soluble contrast agent at the same time or immediately after CT scan. Although the plain CT scan has a higher density resolution than ordinary X-ray examination, there are still some lesions. In the case of a CT scan with an equal density change, or a lesion that has been shown on a plain CT, but it is not clear whether the blood supply is abundant, it is necessary to enhance the lesion by means of contrast. The amount and distribution of contrast agents in various parts of the body often show a certain density and morphological difference according to the characteristics of different tissues and organs and their internal structures (mainly vascular structures). Clinical practice has fully proved that enhanced scanning is markedly The resolution and diagnostic accuracy of CT examination of some organs have been improved. Taking the CT examination of the brain as an example, the accuracy of plain CT is 82%, and the accuracy of enhanced scanning is increased to 92%~95%. CT is suitable for the detection of new organisms in various parts of the body, the location diagnosis of a small number of tumors, the extent of tumor distribution, infiltration and metastasis, and CT-guided biopsy; suitable for the detection of inflammation in most parts of the body and the determination of its size. Such as brain, sputum, sinus, mediastinum, liver (inflammation or abscess such as bacteria or protozoa) inflammation of the pancreas and bones; for the detection of major vascular lesions (vascular malformations, hemangioma, vascular occlusion, bleeding) And qualitative diagnosis; has important value for determining the quantitative and qualitative bleeding of important organ trauma, is also very valuable for the location of a variety of traumatic foreign bodies, and is very sensitive to the detection of calcification or stones in some areas. CT is also suitable for the detection of a degeneration or congenital anomaly, such as liver steatosis and congenital abnormalities of the central nervous system. Basic Information Specialist classification: growth and development check classification: CT Applicable gender: whether men and women apply fasting: not fasting Tips: For patients who have an enhanced scan, the morning checker fasts breakfast and the afternoon checker fasts Chinese food. Normal value There was no abnormality in the CT examination image. Clinical significance Abnormal results CT-enhanced scan can show the gray matter and white matter of the brain tissue, ventricular system and subarachnoid space, which can directly display brain tumor, cerebral hemorrhage, cerebral infarction and other changes; lung examination can clearly show the fine texture of the lung; can be clearly displayed Organs, contours and lesions of the liver, spleen, pancreas, kidney, adrenal gland, etc. Patients who need to be examined for brain tumors, cerebral hemorrhage, cerebral infarction, lung disease, liver, spleen, pancreas, kidney, adrenal gland and other organ diseases. Precautions Taboo before inspection: 1. For patients who do enhanced scanning, the morning examiner fasts breakfast, and the afternoon examiner fasts Chinese food. 2, patients with abdominal CT scan, before the examination should be oral dose of water containing contrast agent, patients with pelvic CT scan, take a large amount of water, or contain contrast water, after the bladder feels full, then CT scan . 3. Patients undergoing CT examination should remove metal objects from the inspection area to reduce artifacts. Requirements for inspection: Actively cooperate with doctors. Inspection process The commonly used CT-enhanced contrast agent in China is 60% of the diatrizoate. The adult dosage is usually 60~100ml. We use 80ml. The dosage of children is calculated according to 1.5ml per kilogram of body weight of 60% diatrizoate, which can achieve satisfactory enhancement effect. . Most of the injection methods use a one-time injection method. The whole amount is injected at about 1.5 minutes, and the scan is immediately performed. The main advantage is that the operation is simple, and the concentration of the contrast agent in the body is high in a short period of time, so it is easy to display the structure of the large blood vessel and its lesions. For quick scanning. With the use of CT pressure injectors, the enhanced scanning of intravenous drip input methods has also been eliminated. CT pressure syringe is used for vein enhanced CT scan. It has been widely used in developed countries. According to the application experience of nearly 500 cases in our hospital, it is considered to be the most ideal vein enhanced CT scan method. It can control the injection under the computer setting program. The total dose of the drug, the staging dose and the speed, and the precise control of how long the injection starts to scan, the biggest advantage is that the side effects of nausea and vomiting after the patient's injection are basically disappeared, and the enhancement effect is good. At present, in the developed countries, non-ionic iodine contrast agents are basically used to replace the ionic iodine contrast agent, and the side effects of the iodine contrast agent are also significantly reduced, but the iodine allergy shock reaction of the non-ionic contrast agent still exists, and it must not be underestimated. Not suitable for the crowd Inappropriate crowd: In general, both ionic and non-ionic contrast agents are used for CT-enhanced scanning, but non-ionic contrast agents should be used instead of ionic contrast agents. First, allergies or ionic contrast agents have a history of allergies (such as the use of ionic contrast agents also need to do iodine allergy test). Second, intracranial intraspinal tumors, aneurysms, vascular malformations and infections. Third, there is a history of epilepsy. Fourth, heart, lung, liver, kidney dysfunction. Five, malignant tumor caused by hungry state, hypoproteinemia, water and electrolyte imbalance. Sixth, infants and elderly patients over 60 years old. Seven, diabetes, hyperthyroidism, eosinophilic patients. Eight, some special scanners (such as dynamic scanning of various parts, liver dual-phase / three-phase scanning, CT angiography, etc.).