Israel M. Gelfand, one of the giants of 20th-century mathematics, whose work cleared paths for other thinkers in fields as diverse as physics and medical imaging, died on Monday in New Brunswick, N.J. He was 96.

The death, at Robert Wood Johnson University Hospital, was confirmed by his wife, Tatiana.

Dr. Gelfand did not achieve fame from attacking and solving famous, intractable problems. Instead, he was a pioneer in untrodden mathematical fields, laying the foundation and creating tools for others to use.

“People always compare him with great mathematicians like Euler or Hilbert or Poincaré,” said Vladimir Retakh, a professor of mathematics at Rutgers, where Dr. Gelfand spent most of his time as a visiting professor after leaving the Soviet Union in 1989.

Dr. Retakh said Vladimir Arnold, a prominent Russian mathematician, had contrasted the approaches of the Soviet Union’s two most famous mathematicians  Dr. Gelfand and Andrei Kolmogorov, who was Dr. Gelfand’s thesis adviser  with a travel analogy.