Summary RADIOLOGY

Plain film x-ray is the most common diagnostic radiological modality used in hospitals today. They were first discovered and used for imaging purposes by Wilhelm Röntgen on 8th November 1895, when he took an image of his wife’s hand X-rays are a type of electromagnetic radiation (just like visible light). There are three criteria that must be met to allow electromagnetic radiation to be used for imaging purposes: Ability to create to the electromagnetic radiation at the wavelength required Ability to focus the radiation on a particular area Ability to detect the radiation once it has passed through the patient The radiation is created when an electric current is generated from a high voltage generator. This causes electrons to “boil-off” from the cathode end of an X-ray tube assembly. These electrons are emitted from a filament on the cathode and rush towards a target material known as the anode. This process is known as thermionic emission. The electrons emitted by the cathode rush towards the anode, which holds a disc made of tungsten. When the electrons collide with the tungsten, several interactions occur at the atomic level. One of these interactions causes electrons to be expelled from the outer orbits of the atoms releasing a X-ray photon. Energy levels of the X-ray photon will vary and can be adjusted when selecting a parameter known as kVP or kilovolts peak