About the Department of Radiology

Our department traces its roots to the beginning of radiology as a scientific and medical discipline. The world's first x-ray image was produced at Penn in 1890 by physics professor Arthur W. Goodspeed and W.N. Jennings, but, at the time, the two did not realize the significance of what they had done. In 1895, German physicist Wilhelm Conrad Roentgen announced his seminal discovery of x-rays, called Roentgen rays at the time. Goodspeed then realized they had produced x-rays years before.

He quickly teamed with Penn surgeons J. William White and Charles Lester Leonard to produce one of the first recorded patient exposures using x-rays. Initially called a skiagraph, it was used to locate a toy jack swallowed by a child. Goodspeed and Leonard wrote the first analytical paper on systematic applications of Roentgen rays to medicine. Leonard was named the first "skiagrapher” at Hospital of the University of Pennsylvania (HUP) in 1896, a post he held until 1902.

In 1897, the Division of Roentgenology Services officially opened at HUP as part of the Department of Surgery, due to surgical interest in x-ray use. It is believed to be the first radiology division or department in the United States. Residents were appointed to the service by the following year. There was one x-ray unit for clinical work and one for research. Soon, the hospital was using the skiagraph to help with diagnosis and treatment of ailments including cancer and lung disease, urological conditions, and for examining the gastrointestinal tract.

Leonard was the first physician in the U.S. to use x-rays as a method to identify urinary stones. He also wrote the first paper on the hazards of X-rays. That work began a long tradition of Penn research into developing better, and safer, x-ray equipment and techniques. Leonard was one of several radiology pioneers who would eventually lose his life due to x-ray exposure from his groundbreaking work.

Henry Pancoast followed Leonard as chief skiagrapher. He identified the utility of bismuth and barium for contrast in radiology studies. Among other contributions, he is known for his description of Pancoast's tumor (a lung tumor that occurs at the apex of the lungs and can cause symptoms that mimic cervical spine disease due to its impact on the nerves that cross the lung apex). He described the relationship of prolonged irradiation to the development of leukemia, as well as x-ray use in the treatment of Hodgkin's disease and leukemia. In 1911, he was appointed the first Professor of Radiology (roentgenology) in the U.S. Pancoast was chairman of the department from 1902 to 1939.

As a "towering figure in radiology for more than half a century," George Edward Pfahler was one of early Penn researchers to study x-ray safety issues. He served as Vice Dean of Radiology at Penn's Graduate School of Medicine.

Residents had entered the radiology service almost from the beginning. A radiology residency training program was formally established at HUP in 1928.

National professional organizations for the field began to form and Penn radiologists were chosen for key roles. Pancoast became the founding president of the American Board of Radiology. Eugene P. Pendergrass was the first chairman of education in the American College of Radiology.

The department itself was evolving to serve scholarly and patient care missions. In 1939, it changed from being a division within the Department of Surgery to become an independent department. Pendergrass chaired the department from 1939 to 1961.

The University's Eldridge Reeves Johnson Foundation for Medical Physics started experiments with ultrasound in 1940 and launched the first biomedical applications of this new discovery. Later in the decade, Britton Chance, a pioneer in biophysics and its applications to medicine, became director of the Johnson Foundation. He trained generations of eminent scholars and researchers in the radiological sciences. With his associates, Chance later developed the technique of optical imaging.

The William H. Donner Center for Radiology, a new campus building, was established. Mortimer Mendelsohn opened the Radiation Biology Laboratory. His work contributed significantly to studies of human cancer treatments.

In the 1960s, Penn researchers were among the pioneers in new types of imaging technology. As the science grew more sophisticated, radiology became a medical specialty, with multiple subspecialties. HUP obtained its first linear accelerator.

Radiologist Stanley Baum, who would become chairman of radiology at Penn, and surgeon Moreye Nusbaum pioneered the field that would come to be known as interventional radiology. Baum and associates used selective intra-arterial catheter vasopressin infusions for the treatment of gastrointestinal bleeding.

David E. Kuhl and Roy Edwards developed the Mark II emission tomographic scanner, starting the field of cross-sectional tomographic imaging. The first transmission construction tomography human image was produced at HUP. This technique led to the development of CT scanning. Kuhl went on to develop single photon emission computed tomography (SPECT) and the principles of positron emission tomography (PET).

Richard H. Chamberlain, department chairman from 1961 to 1975, conducted significant research in radiation safety and measurement.

As the new field of interventional radiology grew, Baum was named founding president of the Society of Cardiovascular and Interventional Radiology (SCVIR). In 1975, Baum became chairman of Penn’s radiology department, a position he held to 1996.

All department faculty became full-time academic faculty of Penn and medical staff of the Hospital of the University of Pennsylvania (HUP). A separate Department of Radiation Oncology was formed.During this period, HUP was the site for several accomplishments. The first in-vivo absolute measurement of local cerebral blood volume in animals and man was performed here. The world's first fluorodeoxyglucose PET image was obtained at HUP, starting a new era in functional imaging

Abass Alavi and associates developed the gastrointestinal bleeding scan. Ronald L. Arenson, Jack W. London and Dan E. Morton initiated technology known as picture archiving and communication system (PACS). Also at HUP, Hans Herlinger developed a technique called enteroclysis, a methylcellulose double contrast small bowel study.

At the start of this period, coincident system based scintillation camera detectors were developed at HUP. The medical image-processing group also was formed. This group helped develop and advance the mathematical basis for tomography and 3D imaging, among many achievements.

The country's first hospital-based MRI became operational at HUP. Growth of the department continued, including expansion of physical and scientific capabilities. The Eugene P. Pendergrass Lab for Radiology Research was inaugurated and the David Devon MRI Building opened.

Reuben Mezrich was appointed interim chairman of radiology in 1996. R. Nick Bryan became Penn’s chairman of radiology in 1999, a position he held until 2012.

Department faculty achieved international reputations for developments in computed tomography (CT), positron emission tomography (PET), and especially magnetic resonance imaging (MRI) modalities. Important contributions include the arterial spin labeling technique that is used to measure tissue perfusion with MRI across the world, and the development of the first radiopharmaceutical approved to imaging the amyloid plaques of Alzheimer’s Disease.

The Stanley Baum Professorship was established in the Department of Radiology. Baum, now chairman emeritus, received gold medals from the American Roentgen Ray Society and Association of University Radiologists.

Mitchell D. Schnall became chairman of the department in 2012. During his two terms as chair of Radiology, Dr. Schnall doubled both the size of the department and its research funding portfolio. He developed training programs and funding pathways for clinician-scientists in Radiology, unified academic programs across UPHS’s Philadelphia hospitals, and created a single Penn Medicine Radiology residency that has been named as the top radiology program in the nation. Schnall also developed strong collaboration between the department’s community-based physicians and its academic programs.

In 2024, Dr. Schnall transitioned to a newly created role as Senior Vice President for Data and Technology Solutions for the University of Pennsylvania Health System (UPHS). At that time, William Stavropoulos, MD, assumed the post of Interim Chair while a national search for a permanent replacement took place.

That search concluded with Pari V. Pandharipande, MD, MPH, FACR, being named the new chair, effective June 1, 2025. Dr. Pandharipande brings strong national leadership experience, currently serving on the Board of Directors for the Radiological Society of North America, where she oversees the Government Relations portfolio, and on the Advisory Board of the American College of Radiology’s Harvey L. Neiman Health Policy Institute. She also has served as Chair of the American Cancer Society’s Healthcare Outcomes, Policy, and Systems grant review committee and currently serves as a member of the NIH’s Organization and Delivery of Health Services study section. She is a past president of the Radiology Alliance for Health Services Research within the Association of Academic Radiology, and she has served on numerous local and national committees, including as a past, longtime Chair of the ACR’s Incidental Findings Committee.