American Roentgen Ray Society 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 technologists. Its 9th meeting, in 1908, was held in New York City. There, it announced that there was "no
Roentgen (unit) In radiation protection the absorbed dose is the energy absorption which is an indication of likely acute tissue effects occurring at high dose rates, and from low levels of absorbed dose the equivalent dose, representing the stochastic health risk, can be calculated; for which the current SI units used are the gray (Gy) and the sievert (Sv) respectively. The roengten has been redefined over the years. It was last defined by the US National Institute of Standards and Technology (NIST) in 1998 as , with a recommendation that the definition be given in every document where the roentgen is used.