In-Field Testing of a New Instrument for Quality Control in Mammography

Abstract

Routine quality control procedures for mammography need a periodical testing of the X ray units. The checks of kVp accuracy, mA linearity, exposure reproducibility and HVL consistency require several instruments (non-invasive kVp meter, dosemeter, absorbers, etc.) and a lot of time. The use of a new instrument for a quick and easy measurement of kVp ripple, HVL, exposure time and incident air kerma is presented. The instrument, composed of an X ray probe and a portable computer, allows the evaluation of the above parameters in a single shot. Two mammographic units have been routinely tested measuring kVp, HVL, exposure time and incident air kerma. The evaluation has been performed exposing the probe during the execution of a performance phantom radiograph. The relationships between the fluctuations of the measured parameters are compared with the limiting values proposed by CEC guidelines. Correlation analysis of the whole data set allows malfunctioning identification. The instrument works properly and is very useful in quality control activity.