Non-Invasive X-ray Multimeters used in Diagnostic Radiology

This review briefly presents the status of non-invasive X-ray multimeters (NIXMs), which are used for quality control (QC) measurements in the useful beams of diagnostic X-ray devices. NIXMs are designed to measure multiple X-ray beam parameters such as the X-ray tube voltage, the dose, the dose rate, the dose per pulse, the irradiation time, the tube current-time (mAs) product, the waveform, the half-value layer (Quick-HVL) and the total filtration (TF) in a single exposure. NIXMs are mainly used in general radiography, fluoroscopy and mammography. Some instruments have been developed for applications in computed tomography (CT). This review includes basic principles, general components, instrument examples, typical specifications, calibrations, international standards and independent performance tests, as well as future challenges.