Allan Cormack; Nobel-Winning Physicist

Nobel laureate Allan Cormack, whose dabbling with a simple algorithm led to the CAT scan, one of this century’s most significant medical advances, has died, Tufts University said Friday. He was 74.

Cormack, a Tufts University physicist, died Thursday at his home in Winchester, a Boston suburb, after a brief illness, the school said.

He shared the 1979 Nobel Prize in medicine and physiology with British engineer Sir Godfrey Newbold Hounsfield for their work that led to the development of the CAT scan. Computerized axial tomographic scanning measures variations in the density of the organ examined and is one of medicine’s most widely used diagnostic tools.

“Millions of patients have directly benefited from his work,” said Dr. John Harrington, dean of Tufts’ medical school.

Cormack was one of a handful of researchers in the 1950s experimenting with mathematical formulas, or algorithms, that converted numerical data to images. He tested his algorithm by building a scanner out of Lucite and aluminum and making a phantom skull to re-create a real-life situation.

Once satisfied that the algorithm worked, “I felt the problem was solved and left the rest to the engineers,” Cormack said in a 1995 interview with a school journal.

Cormack said he was “completely astonished” to have been chosen to share the Nobel Prize. He never earned a doctoral degree. His bachelor’s and master’s degrees were awarded by the University of Cape Town in his native South Africa.

He is survived by his wife, Barbara Seavey, and two daughters.