Basic principle of medical-x-ray machine

Introduction

X-ray is found by Germany professor in 1895. This Vacuum tubes issue radiation which can penetrate object and energy is stronger than visible light on electromagnetic spectrum; Wavelength is shorter and frequency is higher; The similar radiation are Cosmic rays and X-rays.

Produces X-rays, there must be x-ray tube and x-ray tube basic structures are Cathod, Anode, Evacuated glass envelope and Power supply.

There are two ways to produce X-ray

Bremsstrahlung: After High-speed electronic slowing down suddenly, kinetic energy turn into energy and release. The energy is the X-ray and it will be different with slowdown extent.

Characteristic: High-speed electronic hit atoms and electronic of peripheral orbit and make it dissociate and release energy, it is X-ray.

Producing way proportion of diagnosis X-ray: 30% is Characteristic and 70% is Bremsstrahlung

X-ray characters: First, It can penetrate object;

Second, it is no visible light

Third, it is in electromagnetic spectrum

Fourth, Wavelength range is widely

Fifth, Linear scattering

Sixth, it runs by light speed

Seventh, it can make Fluorescent object shine

Eighth, it can make film exposure

Ninth, it will cause scattering line

When X-ray go into object, there are three conditions: Firstly, it is absorbed by object;

Secondly, it produces scattering line

Thirdly, Penetration

There are four factors impacting Radiographic Quality

Density, Contrast, Sharpness and Distortion

X-ray wavelength is relative with contrast:

X-ray can penetrate patient and penetration rate is relative with the patient organization structure and X-Ray wavelength.

Short wavelength energy is higher and penetrating is good and it causes lower contrast on film.

Long wavelength X-ray

The energy is lower and is easy to be absorbed by people and penetrating is bad and it causes higher contrast on film.

本文由廣州佳譽(yù)醫(yī)療器械有限公司編輯