American Roentgen Ray Society excuse whatever" for anyone being injured during medical X-rays, which "could be taken in a fraction of a second". American Roentgen Ray Society The American Roentgen Ray Society (ARRS) is a radiology society in the United States. It was founded in 1900, in the early days of X-ray and radiation study. Headquartered in Leesburg, Virginia, the society publishes a monthly peer-reviewed journal: "American Journal of Roentgenology" (previously "American Journal of Radiology"), providing a forum for advances in radiology and related fields. It provides scholarships, and presents awards. Its educational programs include seminars and a program of continuing education for radiologic
Roentgen (unit) 1962 it was redefined. The CCU decided to define the SI unit of absorbed radiation in terms of energy per unit mass, which in MKS units was J/kg. This was confirmed in 1975 by the 15th CGPM, and the unit was named the "gray" in honour of Louis Harold Gray, who had died in 1965. The gray was equal to 100 rad. The definition of the roentgen had had the attraction of being relatively simple to define for photons in air, but the gray is independent of the primary ionizing radiation type, and can be used for both kerma and