What's the difference between filming and ct?

Generally speaking, X-ray examination is only used for filming, and the obtained images are overlapping images. Many lesions can not be diagnosed accurately by radiography, and the rate of missed diagnosis is also high.

CT is X-ray computed tomography, which can eliminate the interference of overlapping images and improve the diagnostic accuracy, but at the same time, it receives more X-ray radiation than radiography.

2, the working principle is different

Shooting process: Gray filter is to turn a picture into a gray image. Inverse filter inverts all visual properties of an object, including color, saturation and brightness values. X-ray filter is to make an object reflect its contours and highlight these contours, which is the so-called "X" optical film.

The working procedure of CT: It measures the human body with a highly sensitive instrument according to the different absorption and transmission of X-rays by different tissues of the human body, and then inputs the measured data into an electronic computer. After processing the data, the electronic computer can take a cross-sectional or three-dimensional image of the examined part of the human body and find tiny lesions in any part of the body.

Extended data:

1, X-rays are audio-visual materials.

Audio-visual materials include audio tapes, video tapes, cinematographic films or sounds, moving images and graphics stored in computer-related equipment. Knowledge carrier, also known as audio-visual materials or direct-feeling materials, is generally recorded in the form of sound and image. Audio-visual materials can generally be divided into three types:

1) Visual materials are also called silent image materials, including pictures, photographic films, slides, slides, silent video tapes, silent movies and silent machine-readable materials.

2) Auditory materials, also called recording materials, include records and tapes.

3) Audio-visual materials are also called audio-visual materials or audio-visual materials, including movies, TV series, audio-visual films, audio-visual discs, etc.

2.CT scanning methods include plain scanning, enhanced scanning and enhanced scanning.

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

2) Enhanced scanning: inject water-soluble organic iodine agent, such as 60% ~ 76% meglumine diatrizoate 60ml, and then scan. 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 The main methods are mass injection and intravenous drip.

3) Contrast scanning: It is a method to compare organs or structures before scanning. If 8 ~ 10 ml lipiodol or 4 ~ 6 ml air is injected into the cistern for cisternography and then scanned, it is called cisternography CT scan, which can clearly show the cistern and its small tumors.

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