John Fennessy, professor emeritus and former chair of the University of Chicago department of radiology, died earlier this month from complications following cardiac surgery. He was 82.

As detailed in the University of Chicago’s touching tribute, Fennessy was considered “the final authority” on the subject of radiologic examinations of the chest or abdomen. Other physicians would also turn to him with questions about specific x-rays.

Graduating medical students at the University of Chicago selected Fennessy as a favorite faculty member 30 different times over the years, and he won the school’s McClintock Award for Outstanding Teaching in 1969. He was also a founding member of the Society of Thoracic Radiology and a member of the Fleischner Society.

Fennessy completed his medical degree in Dublin, Ireland, in 1958, moving to the United States the following year. He then worked as an intern at Mercy Hospital in Chicago, eventually beginning his time with the University of Chicago in 1960 as a resident. Fennessy then went on to serve as the school’s chairman of radiology for ten years.

The University of Chicago wrote about Fennessy’s lasting legacy in radiology: “Fennessy had a direct impact on the field. One of his first papers, published in 1966, expanded on a technique developed in Japan in which radiologists inserted a catheter into the lung to obtain tissue from lesions at the periphery of the bronchial tree. Fennessy’s innovative adaptation, known as the bronchial brush, enabled physicians to acquire better samples from hard-to-reach areas of the lungs, without the need for an incision. His technique was widely disseminated in the United States and abroad.”