DR is mainly composed of X-ray tube, X-ray high voltage generator, flat panel detector, mechanical parts and imaging system. The key to X-ray imaging is the density value. Features: low price, simple, radiation.
X-rays, visible light, and ultraviolet light are all forms of the electromagnetic spectrum, but with different wavelengths and frequencies. Because the wavelength of X-ray is very short, shorter than the wavelength of atoms, and the energy is very penetrating, it can interact with atoms, thereby ionizing it. The ions continue to react and interact with the DNA to cause mutations, the radiation problem we all care about.
Film is sensitive to X-rays, and X-rays expose the film, so CT was born. Shoot multiple images from different angles, and then use the algorithm to superimpose them into 3 dimensions. The bone density is high, so it is very bright when shooting.
Using the difference in the signal generated by the absorption of X-rays by the human body to image, the X-ray film is equivalent to pressing the person into a plane, and then look at the difference in the absorption density of X-rays on this plane.
Therefore, X-rays are good for high-density substances such as bones. Especially foreign bodies, because foreign bodies generally have a relatively high density. In the examination of bones, spine, joints and other organic lesions, the location, size, degree and relationship with the surrounding soft tissue of the lesions are clearly defined.
Post time: Mar-02-2022