Radiological Society of North America
The Radiological Society of North America (RSNA) is one of the largest radiological societies in the world with more than 54,000 members.
The first American radiological society, the American Roentgen Ray Society (ARRS), was by the mid-1910s, seen very much as an organization of the Eastern portion of the United States; the vast majority of its members were from States in the East of the country, and almost all its meetings were held there. It was difficult for members from the Western portion of the Union to travel to meetings in the East, for both financial reasons and the necessary lengthy absence from their medical practices. The ARRS had made efforts to mitigate this bias, for example, by organizing "Western Section" meetings, however, it was unsuccessful.
In 1915, Edwin C Ernst, a radiologist from St Louis, following his return home after a meeting of the American Roentgen Ray Society, decided that the time had come to establish a separate radiological association for the Western and central US (i.e. Midwest). An inaugural organisational meeting was held at the Sherman Hotel in Chicago on 15-16 December 1915. This new membership organization was called the Western Roentgen Society.
Despite being established as a society for the West of the country, by 1919 it boasted of 472 members from 38 states, and was closer to being a nationwide organization than the older and - more prestigious - American Roentgen Ray Society. Thus in 1920, the Western Roentgen Society became the Radiological Society of North America (RSNA).