AbstractID: 8516 Title: Experimental Verification of Practical Peak Voltage for the
Mammographic Range
This project serves to experimentally verify the concept of Practical Peak Voltage (PPV). The concept of PPV was first published in
1998 by Drs. Kramer and Selbach. PPV is akin to kVp, the current parameter used to characterize the maximum energy of the
photons produced by an x-ray tube. Due to various types of generators used to power x-ray tubes, it is possible to obtain differing
radiographic contrast values for machines measuring the same kVp. This problem led to the creation of PPV, an algorithm that
determines the equivalent voltage applied to a constant potential x-ray machine that would produce the same contrast on a radiograph
as the generator under test. The goal of this project is to check the PPV algorithm found by Drs. Kramer and Selbach with data
collected in the mammographic range of voltages (between 25 to 50 kV). This data consists of air kerma measurements of a constant
potential x-ray generator with and without a contrast material, using an Attix Free Air Chamber. By finding the ratio between those
two air kerma rates, the contrast equivalent voltage (CEV) can be found for a voltage waveform. The measurement has determined
that theory (PPV) and experimental measurement (CEV) for tungsten targets in the mammographic range agree to within 0.5 %. The
PPV algorithm can be easily incorporated into a non-invasive measuring device whose readout will now be directly related to the low
level contrast properties of the radiographic image.