The death was announced in a statement by Fonar Corp., which Dr. Damadian founded in 1978 after being awarded a patent for the MRI concept of using radio waves from atoms to construct images of soft tissue. No cause was given.

Dr. Damadian is credited with helping build the foundations for one the major advances in the modern medical tool kit, offering the ability to detect potentially cancerous tumors and observe internal organs without invasive procedures or the radiation from X-rays or CT scans. Since MRI experiments in the 1970s, the systems have become an essential part of medical tests around the world.

Dr. Damadian was often at odds with the wider medical community, building a reputation as a zealous self-promoter and go-it-alone eccentric who tried an early MRI test on himself by wriggling into the coils of a prototype machine he dubbed “Indomitable.” A PBS biographical sketch described him as a brilliant innovator but, at times, off-putting with an “abrasive, aggressive personality.”

He battled companies such as Johnson & Johnson over alleged patent infringements and broke from established science to apparently embrace biblical creationism over evolution. In 2015, he co-authored “Gifted Mind: The Dr. Raymond Damadian Story, Inventor of the MRI” that blended his work with his views on faith.

The biggest fissure came after the 2003 Nobel Prize in science was awarded Paul C. Lauterbur of the University of Illinois at Urbana-Champaign and Peter Mansfield of the University of Nottingham in Britain for their work in MRI development. He was outraged at being overlooked.

He began a public campaign decrying the Nobel decision and openly lobbying for the award, which he claimed should rightfully include him.

“The shameful wrong that must be righted,” said a full-page ad by Dr. Damadian that appeared in The Washington Post and other major newspapers around the world. At the bottom was a clip-and-mail coupon, addressed to the Nobel Committee for Physiology or Medicine, calling for Dr. Damadian to be added to the award. The ad featured an image of the Nobel Prize upside down.

The Nobel Committee did not alter its decision.

“To wake up Monday morning and see that I have been erased from history,” he told the New York Times after the Nobel announcement from Stockholm. “It is a torment that I can neither bear nor live with.”

Lauterbur and Mansfield were foundational in bringing MRI technology into practical use; Lauterbur with conceiving how to turn the radio signals into workable images, and Mansfield with mathematical techniques for interpreting the data. Dr. Damadian’s early work, colleagues said, had an important but more limited focus: exploring how cancer cells produced different radio signatures than normal cells after being tugged by a magnetic field.

It was nonetheless a significant breakthrough, and his appeal for Nobel recognition had some backers among MRI experts. Yet Dr. Damadian’s brusque style may have worked against him, some colleagues said.

“A more likely reason that Dr. Damadian did not win the award has to do with his less-than-subtle self-promoting activities over the past 20 years,” wrote William G. Bradley, a professor at the University of California at San Diego, in a 2004 issue of the Journal of Magnetic Resonance Imaging. “Because I have known Raymond Damadian for 20 years and consider him a friend, I have always questioned why a brilliant scientist needed to resort to relatively provocative tactics to be appreciated.”

Began with lab rats

Raymond Vahan Damadian was born in Manhattan on March 16, 1936, and raised in Queens. His father, an ethnic Armenian immigrant, was a photoengraver at the New York World-Telegram; his mother was an accountant.

Dr. Damadian took an early interest in music and studied violin with some boyhood classes at the Juilliard School. He decided to shift to medicine after winning a scholarship to the University of Wisconsin at Madison, graduating in 1956. He received a medical degree in 1960 from New York’s Albert Einstein College of Medicine.

He began experimenting with nuclear magnetic resonance technology (NMR), a technique discovered in the late 1930s in which a constant magnetic field is used to measure radio waves from atomic nuclei. At the time, it was used on a small scale to identify chemical compositions.

Dr. Damadian, then at the Downstate Medical Center in Brooklyn (now SUNY Downstate Health Sciences University), proposed the idea of a full-body scanner. He postulated that it would pick up different radio signatures between normal tissue and cancerous sites.

“I thought if we could do on a human what we just did on that test tube, maybe we could build a scanner that would go over the body to hunt down cancer.” he told Inc. magazine in 2011. “It was kind of preposterous. But I had hope.”

In June 1970, he packed up some lab rats in his car and drove to an NMR lab in Pittsburgh, publishing the results of cancer detection in Science the following year. With a grant from the National Cancer Institute, Dr. Damadian started to build the first body scanner even before the term MRI was coined. His patent application shows the general structure of the modern machine with magnetic coils surrounding a bed for the patient.

In the summer of 1977, Dr. Damadian was ready to test the 1.5-ton machine (now in the Smithsonian Institution). He shimmied inside, but there were no readings.

“Frankly, I was just too fat for that coil,” he said. He turned to lab assistant Lawrence Minkoff. On July 3, 1977, Dr. Damadian triumphantly announced the first MRI image, a portion of the Minkoff’s chest showing his heart, lungs and other organs.

Yet other battles were beginning.

Some colleagues thought Dr. Damadian was overplaying the moment, including his news release that he had “perfected” cancer detection before there were even any human trials. Dr. Damadian countered that he had used MRI technology to find cancer cells in rats and had studied cancerous tissue removed from humans.

He found trouble getting new grants and looked to private investors, which offered the seed money to found Fonar in Melville, N.Y., an acronym built off Field Focused Nuclear Magnetic Resonance. It produced its first commercial MRI machine, QED 80, in 1980.

At the same time, others were moving into the market using their own variations of the original NMR technology. Dr. Damadian saw it as patent theft.

He lost a claim against Johnson & Johnson in 1986 but, in 1997, a federal appeals court upheld a more than $100 million decision against General Electric for patent infringement. Other companies, including Germany’s Siemens and Japan’s Hitachi, reached out-of-court settlements with Dr. Damadian and Fonar.

The money helped keep Fonar going. The company later introduced innovations such as MRI machines that allow the patient to sit upright. Dr. Damadian also helped develop a pacemaker compatible with MRI technology.

His wife of 60 years, Donna Terry, died in 2020. Survivors include three children, Keira Reinmund, Jevan Damadian and Timothy Damadian, who is Fonar chief executive; a sister; nine grandchildren; and three great-grandchildren.

Despite his anger over the Nobel decision, Dr. Damadian received a stream of awards for his MRI work. At his induction into the National Inventors Hall of Fame in 1989, he used the ceremony in Akron, Ohio, to grouse about his patent fights.

“Patents don’t work,” he said. “I now have to compete against the Japanese in a market that I created with my own invention.”