Fonar Corp. v. General Electric Co.
"Fonar" was a dispute between medical device manufacturer Fonar Corporation and General Electric over Fonar's patent on MRI technology. Fonar's founder, Raymond Damadian, was issued U.S. Patent 3,789,832 (priority date 1972-03-17) for an "apparatus and method for detecting cancer in tissue" using the magnetic resonance of atoms. Damadian's patent was the first patent on an MRI machine issued in the United States. Also at issue was a later patent, U.S. Patent 4,871,966 issued in 1989, covering a method for obtaining MRI images of multiple planes at different orientations in a single scan. GE is a major manufacturer of MRI scanners, and Fonar sued GE for infringing these patents by producing its scanners as well as inducing others to infringe.
Magnetorotational instability
The MRI was first noticed in a non-astrophysical context by Evgeny Velikhov in 1959 when considering the stability of Couette flow of an ideal hydromagnetic fluid. His result was later generalized by S. Chandrasekhar in 1960. This mechanism was proposed by Acheson & Hide (1973) to perhaps play a role in the context of the Earth's geodynamo problem. Although there was some follow-up work in later decades (Fricke, 1969; Acheson and Hide 1972; Acheson and Gibbons 1978), the generality and power of the instability were not fully appreciated until 1991, when Balbus & Hawley gave a relatively simple elucidation and physical explanation of this important process.