Ct is a kind of photography operated and processed by computer.

Ct is an image photography processed by computer operation.

Introduction to CT:

CT is a fully functional disease detection instrument, which is the abbreviation of computerized X-ray tomography. CT examination is based on the different absorption and transmission of X-rays by different tissues of the human body, measuring the human body with highly sensitive instruments, and then inputting the measured data into an electronic computer.

After processing the data, the computer can take a cross-section or three-dimensional image of the examined part of the human body and find tiny lesions in any part of the body.

Matters needing attention in CT examination:

1, fasting for 4 hours before abdominal CT examination, preferably starting the night before.

2. 1 week refused to accept drugs containing heavy metals, and did not do gastrointestinal barium meal examination. Patients who have undergone barium examination must wait until the barium is emptied; Those who are eager for CT examination should be given clean enema or oral laxatives to expel barium before CT examination.

3. Be sure to remove the high-density or metal objects at the inspection site before inspection.

4. Patients who need enhanced scanning should do iodine allergy test in advance. Requirements during examination: actively cooperate with doctors and pay attention to protective shielding outside scanning examination.

The process of CT examination and its clinical significance;

1, inspection process:

(1) Plain scan refers to ordinary scan without contrast enhancement or contrast. Usually, a normal scan is performed first.

(2) Contrast-enhanced scanning is a method of intravenous injection of water-soluble organic iodine, such as 60%-76% meglumine diatrizoate, and then scanning. After the concentration of iodine in blood increases, the concentration of iodine in organs and lesions can be different, resulting in density difference, which may make the lesions develop more clearly. Methods There are three methods: group injection, intravenous drip and intravenous drip.

(3) Contrast scanning is a method to compare organs or structures before scanning. If 8- 10 ml lipiodol or 4-6 ml air is injected into the cisterna cerebri for cisternography, and then the cisterna cerebri and its small tumor can be clearly displayed by CT scanning.

Clinical significance:

Middle ear cancer can be manifested as bone destruction centered on the middle ear, complete disappearance of ossicles and local soft tissue masses. The CT manifestations of sinusitis are mucosal thickening, increased density in the cavity and formation of effusion or pus. On plain scan, most liver cancers show low density areas. The CT manifestations of liver cirrhosis include uneven liver surface, unbalanced proportion of each lobe, uneven density of liver parenchyma and splenomegaly.

Patients with acute pancreatitis present with subchronic enlargement, deformation and blurred edges of the pancreas.