Development of medical imaging and patient doses In Germany the x rays were discovered by Wilhelm Roentgen in 1895 and in 1905 he was awarded the Nobel Prize in recognition of his contributions to physics After this discovery the new x ray technology was rapidly applied in clinical medicine There is no published information documenting the starting use of ionizing radiation in diagnosis in Saudi Arabia but in 1950 it began to pay attention to safety health and established the first Public Health Department in Makah This was followed by establishing the first hospital of King Saud in Riyadh as early as 1956 1 Since 1896 the x ray in the United States was rapidly applied in clinical medicine and the number of radiologic examinations increased about tenfold between 1980 and 2006 2 The availability of x ray technology and the volume of medical imaging can vary extensively from country to country however in Saudi Arabia the growing of x ray technology was increased and potentially increase the radiation dose received by the patients and this has concerned physicians and radiation physicists as well as regulatory bodies such as the National Center for Radiation Protection SNCRP in King Abdul Aziz City for Science and Technology KACST