What are image quality indicators?
IQI – Image Quality Indicator – is a device for showing the quality of a radiograph. The unsharpness or blurring of the image; The contrast or change in density on an image for a known change in thickness in the specimen; The noise on the image, eg the graininess of the film.
What is sensitivity in radiography?
The sensitivity is taken as the smallest diameter wire that can be seen divided by the component thickness, expressed as a percentage. Most application codes specify a sensitivity of between 2-4% ; this is a maximum, the smaller the figure the greater the sensitivity of the radiograph.
What is 2 2T sensitivity?
Normally a plaque in which T is 2% of the specimen thickness is used (ASTM E 1025-95) but, in some applications, a 1% plaque may be specified. If the 2T hole in a 2% plaque is discernible, this is quoted as 2-2T ASTM sensitivity level.
What is the purpose of IQI?
The IQI is used to indicate the quality of the radiographic technique and not intended to be used as a measure of the size of a cavity that can be located on the radiograph.
Why are image quality indicators used in radiography testing?
The image quality indicators (IQIs), which are also referred to as penetrameters, are test pieces used to control a radiograph’s quality. IQI indicates the contrast sensitivity and definition of the radiograph and serves the purpose of product testing.
What is radiographic density?
Radiographic Density – the overall amount / degree of darkening on a radiograph. In routine radiography, the useful range of density varies from 0.3 to 2.0 density. The density below 0.3 is due to the density produced by the base and by some fog on the film (base plus fog).
What is sensitivity in digital radiography?
Sensitivity in digital radiograph images shows very high quality image at minimum reduction of exposure time.
What are the 5 basic radiographic densities?
The five basic radiographic densities: air, fat, water (soft tissue), bone, and metal. Air is the most radiolucent (blackest) and metal is the most radiopaque (whitest).
What is wire IQI?
Wire-type IQIs or penetrameters consist of a series of metal wires mounted in a flexible plastic holder. The wires are mounted parallel to each other, about 5 mm apart and about 60 mm long. Image quality indicators (IQI) wire type penetrameters are also available in plaque and hole type.
How do I select IQI in radiography?
The IQI is placed on a radiography film while doing the radiography. The image will be caught in the film. If the wire having 0.16mm diameter is visible in the radiography film, then we can say that the film is having a sensitivity of this 2%. The IQI that is commonly used is of ASTM and DIN standards.