History of the Society

The Philadelphia Roentgen Ray Society (PRRS) is the oldest regional radiological society in North America. National and local and national speakers are featured at its meetings held each year between October and May at the historic College of Physicians in Center City Philadelphia.

The Society is a forum of discussion for significant issues in Radiology, serving a large audience of graduate physicians, fellows, resident physicians and members of the allied health professions from the Greater Delaware Valley.

The PRRS fulfills an important function by disseminating significant radiological information while continuing to serve as a venue for good fellowship and promoting a sense of community amongst radiologists and radiation oncologists.

How We Started

The Roentgen Ray Society of Philadelphia was organized February 2, 1905, through the efforts of Dr. Charles Lester Leonard (photo left) who, in 1898, had effectively become the first chair of radiology at the University of Pennsylvania.

Dr. Leonard invited a dozen pioneers in the new field of Roentgenology to his private office to organize a local society for the “study of the roentgen ray and the formation of friendly intercourse.” This group included the physicians responsible for Roentgenology departments in Philadelphia hospitals plus specialists in other medical fields and scientists and engineers who were in some way involved in the development of this new specialty. A number of additional prominent radiologists from other cities were also elected as corresponding members who occasionally attended. This was the beginning of the Philadelphia Roentgen Ray Society.

From the start, this society was interested in radiation protection and new developments in the field. In addition, members also brought x-ray plates from unusual or difficult cases to the meetings leading to informal discussions which provided the early precedent for city-wide film reading sessions.

The prospering of the Society and the rare quality of good fellowship and cooperation among its members were due, in no small degree, to the responsibility which Dr. Leonard was willing to assume as Permanent Secretary. He continued in that position until his death in 1913 from radiation-induced cancer.

As a result of Dr. Leonard’s death, a more formal organization was created. A Constitution and Bylaws were adopted and enacted on December 1, 1913. In the next few years, there was an unimaginable surge of interest and Roentgenology flourished. The following decade saw a large increase in membership. On October 2, 1924, the Society was officially incorporated as the Philadelphia Roentgen Ray Society, Inc., and the Constitution was revised.

In 2005, the Society celebrated the 100th anniversary of its founding at a gala held at the College of Physicians looking forward to another century of service and fellowship for its profession.


Letter to the PRRS Membership from Elizabeth A. Patterson, MD, President, PRRS, at the start of the 1994-1995 centennial of the discovery of x-ray celebration.

From the “Preamble” to the “PRRS Constitution and Bylaws” (dated April 1993) in the PRRS files

Photo of Dr. Charles Lester Leonard from the Department of Radiology at the Hospital of the University of Pennsylvania (via Wikimedia)

Past Presidents of the Society

Data for the Archives

Annual Oration Honorees

Annual Oration Honorees

Outstanding Educator Awardees

The Outstanding Educator Award was established in October 1991 and was named in memory of Mary Stuart Fisher, MD in 2007.

Outstanding Educator Awardees