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.