What is CT and the imaging principle of CT

What is CT and the imaging principle of CT

Computed Tomography (CT) is a new diagnostic technique combined with the rapid development of electronic computer and X-ray in the past ten years. Its main characteristics are high density resolution, 10~20 times higher than ordinary X-ray photographs. It can accurately detect the small difference of radiation attenuation characteristics between different tissues of a certain plane, and display it with images or numbers, and distinguish the different densities of various soft tissues extremely carefully, thus forming a contrast. If the craniocerebral X-ray film can not distinguish brain tissue and cerebrospinal fluid, CT can not only show the ventricle system, but also distinguish the gray matter and white matter of the brain. For example, the contrast agent is introduced to enhance contrast and improve its resolution, so the diagnosis of the disease is widened and the correct rate of diagnosis is raised. But CT also has its limitations, such as vascular lesions, endoluminal lesions, and certain lesions.

CT is used to scan the layer of a certain thickness of the human body by X-ray beam. The detector receives the X-ray of this layer and turns into visible light, then the photoelectric converter is converted to the electrical signal, then the analog / digital converter is converted to the digital, and the computer is transferred to the computer. The processing of image formation is divided into several volumes of the same cuboid, called voxel. The scanned information is calculated to obtain the X – ray attenuation coefficient or absorption coefficient of each voxel, and then arranged into a matrix, that is, digital matrix. The digital matrix can be stored in a disk or disk. The digital / analog converter turns each number in the digital matrix into small squares from black to white, that is, the pixel, and is arranged in matrix, that is, the CT image is formed.

Author: X Ray Machine Accessories