Along with the mAs ( tube current and exposure time product ) and filtration, kVp (tube voltage) is one of the primary settings that can be adjusted on x-ray machines to control the image quality and patient dose.
2/27/2016 · If a repeat radiograph is necessary and kVp is to be adjusted to either increase or decrease the level of contrast, the 15% rule provides an acceptable method of adjustment. In addition, whenever a 15% change is made in the kVp to maintain the exposure to the IR, the radiographer must adjust the mAs by a factor of 2.
In digital imaging, the kVp affects the variation in radiation intensities exiting the patient and image contrast however, image brightness and contrast are primarily controlled during computer processing. When a kVp that is too low is selected, the brightness and contrast are adjusted, but quantum noise may be visible.
kVp Levels and Automatic Exposure Control Response. The radiographer must set the kVp value as needed to ensure adequate penetration and to produce the appropriate level of contrast. The kVp selected determines the length of exposure time when using AEC. A low kVp requires more exposure time to reach the predetermined amount of exposure.
The image shown above was generated at 75 kV and required an exposure of 36 mAs. The increase in x-ray tube voltage increases the amount of radiation coming out of the x-ray tube, as well as the average photon energy (i.e.
increased penetration).
Kilovoltage peak | Radiology Reference Article …
Exposure Technique Selection | Radiology Key, Exposure Technique Factors | Radiology Key, Exposure Technique Factors | Radiology Key, Adjustments in kVp should be used to control radiographic ___. contrast The factors that affect x-ray emission under the direct control of the radiographer are called the ___ factors.
it is NOT recommended to use kVp to control density. 15% rule. increasing kVp by 15% = doubling mAs (which means increasing kVp by 15% has the same effect as doubling the mAs) increasing kVp by 15% will double the density on an image or increase density by 100%
