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 stereophotogrammetry Roentgen stereophotogrammetry Roentgen stereophotogrammetry (RSA) is a highly accurate technique for the assessment of three-dimensional migration and micromotion of a joint replacement prosthesis relative to the bone it is attached to. It was introduced in 1974 by Goran Selvic. Several studies have found implant migration to be predictive of long-term implant survival and, for most devices, measurement over 2 years might therefore provide a surrogate outcome measure with relatively low numbers of subjects, e.g. from 15 to 25 patients in each group in randomized studies. A smaller number of subjects can be used in these studies as a consequence of