Fundamental Physics of Radiology focuses on how radiation is produced, how the rays interact and affect irradiated material, and the principles underlying the apparatus being used. The publication first takes a look at matter and energy, radiation, and spectra, atoms and nuclei, and radioactivity, including electromagnetic radiation, waves and photons, atomic and nuclear structures, and electromagnetic spectrum. The text also ponders on radioactive materials and the effects and production of X-rays. The text examines the measurement of X-ray quantity, roentgen and its measurement, and the Geiger-Müller and scintillation counters, as well as departmental chambers, instruments in practice, and ‘free-air‘ chamber. The manuscript also elaborates on properties of X-ray film, intensifying and fluorescent screens, effect of X-ray absorption on radiographic image, and effects and control of scattered radiation. The publication is a dependable reference for physicists and readers interested in radiology.