The estate of a deceased radiologist and his wife recently donated $1.3 million to an endowment fund at Roper St. Francis Healthcare, the largest donation in the nonprofit's history.

Harold S. Pettit served as chief of radiology at Roper Hospital from 1949 to 1983, and served on the hospital's board of commissioners for 19 years. He continued his radiology practice until a few weeks before he died in 1987.

His wife, Corinne, continued the family's involvement with Roper, serving on the hospital's foundation board until 1999. She died last year.

"Dr. and Mrs. Pettit have always had a great deal of affection for the Roper Hospital family, including the physicians and staff," said John P. Linton, executor of the Pettits' estate.

The hospital plans to use the donation to acquire state-of-the-art medical equipment and make other improvements at Roper.

The hospital said donations in recent years have helped it buy Cyberknives, a noninvasive radiation alternative to surgery, a robotic surgical system, as well as new gardens and improvements to Roper's surgical pavilion, hospital officials said.