title: Raymond Damadian
context: Damadian's research into sodium and potassium in living cells led him to his first experiments with nuclear magnetic resonance (NMR) which caused him to first propose the MR body scanner in 1969. Damadian discovered that tumors and normal tissue can be distinguished in vivo by nuclear magnetic resonance (NMR) because of their prolonged relaxation times, both T1 (spin-lattice relaxation) or T2 (spin-spin relaxation). Damadian was the first to perform a full body scan of a human being in 1977 to diagnose cancer. Damadian invented an apparatus and method to use NMR safely and accurately to scan the human body, a method now well known as magnetic resonance imaging (MRI).[2]
question: When was the MRI invented?
answers: 1969