Matters needing attention in doing CT

The following people can't do CT examination:

1, renal insufficiency.

2, diabetes, multiple myeloma, dehydration, severe cerebral arteriosclerosis and cerebral vasospasm, acute pancreatitis, acute thrombophlebitis, severe cachexia and other serious diseases.

3. Asthma, hay fever, urticaria, eczema and other allergic diseases.

4, heart disease: such as congestive heart failure, coronary heart disease, arrhythmia and so on.

5. Patients with previous history of contrast agent allergy and other drug allergy.

6, 1 children under the age of 60 and the elderly over 60.

Extended data:

Features of CT images:

1, CT image is formed by arranging a certain number of pixels with different gray levels from black to white in a matrix. These pixels reflect the X-ray absorption coefficient of the corresponding voxel. Different CT devices have different pixel sizes and numbers.

2.CT images are expressed in different gray levels, reflecting the degree of absorption of X-rays by organs and tissues. Therefore, like the black-and-white images displayed by X-rays, black shadows represent low absorption areas, that is, low density areas, such as lungs with more gas; White shadow indicates high absorption area, that is, high density area, such as bone.

3.CT images are slice images, which are commonly used in cross sections. In order to display the whole organ, multiple continuous slice images are needed. By using the image reconstruction program on CT equipment, coronal and sagittal images can be reconstructed, and the relationship between organs and lesions can be observed from multiple angles.

Baidu encyclopedia -CT examination

Baidu encyclopedia -CT scanning