RHS Exam Outline- Radiation Safety. Exam Review. Top Questions and answers. Graded A+

RHS Exam Outline- Radiation Safety. Exam Review. Top Questions and answers. Graded A+ Composition of typical radiographic film... - Double-sided or double-emulsion film - In the center of the film, there is a transparent, blue-colored plastic sheet or base. - An emulsion is attached to either side of the base with some type of adhesive. The emulsion is a mixture of silver halide or silver iodobromide crystals, which interact with x-ray photons to produce what is known as a latent or invisible image, and clear gelatin. The silver compounds usually employed are 90% or greater silver bromide (chemical formula AgBr) and silver iodide (AgI) as the remainder. The outer layer on both sides of the radiographic film is a protective coating. Latent image An invisible image that you produced in film emulsion by light an x-ray and is converted into a visible image by processing. Benson Line Focus Principle Reduces the effective dimensions of the focal spot. This is accomplished by an anode design with an angled face to the electron path, typically at 15-20° relative to the cathode. The resultant “effective” focal spot isconsiderably smaller than the spot on the anode and image quality is improved. In addition, the anode can absorb more heat because it is spread over a larger area of that electrode. Electrons are generated in the... tungsten filament of the cathode of the x-ray tube. Kinetic or motion-related energy is... Electrons streaming from the cathode to the anode in an x-ray tube Types of radiation... 1. 2. 3. 1. Bremsstrahlung 2. Characteristic 3.Heterogeneious/Homogeneous Bremsstrahlung radiation Dominant type of x-ray elicited by dental x-ray equipment. Characteristic radiation a high-energy electron from the cathode ionizes or removes an electron from an inner orbit of the target. Heterogeneous radiation Most Brems radiation emitted from a typical dental x-ray tube controlled by alternating current (AC) --- MEANING: The radiation is released in a range of energies and wavelengths. Homogeneous radiation If the apparatus is designed to convert the AC to direct current (DC), MEANING: greater penetration of the soft tissues is achieved, and image quality is improved X-ray generators are composed of two main parts... 1. 2. 1. Control Pannel 2. Tube head assembly Control pannel Controls... 1. exposure time 2. current selection (mA or milliamperes) 3.Potential difference (kVp or kilovoltage peak) Tubehead assembly consists of... The tube and transformers Self-rectification Effective conversion of the alternating current to unidirectional direct current (DC) Transformers are... Electromagnetic pieces of equipment that step the voltage potential difference up or down in an efficient manner More photons of x-ray energy are generated by decreasing/ increasing the exposure time increasing Umbra Central sharp area of a radiographic image Penumbra Blurry area The less sharp penumbra area can be reduced by increasing/decreasing the target area on the anode and the effective focal area. decreasing Definition is directly related to contrast. true or false? true Ionization The conversion of an atom from a neutral to either a positive or negative charge. Ion A charged atom Gamma rays discharged from disintegrating radioactive nuclei X-rays are... Emitted outside the nucleus without mass or electrical charge. X-rays can travel through tissues further than other forms of radiation without/ with focal localization, making them important for forms of diagnostic radiology including dental radiographs. without The long wavelength, low frequency forms include .... 1. 2. 3. 1. alternating current waves 3. television these wave cycles rang