Magnetic resonance imaging

Magnetic resonance imaging emerged from the convergent insights of three scientists working on different continents, each contributing essential pieces to a diagnostic technology that would revolutionize medicine—and then fighting bitterly over credit for decades.

The adjacent possible required nuclear magnetic resonance, discovered in 1946 by Felix Bloch and Edward Purcell. NMR measured how hydrogen atoms in different chemical environments responded to radio waves in a magnetic field—useful for analyzing molecular structures in test tubes but seemingly impractical for imaging living bodies. The leap from chemistry to medicine required recognizing that tissues contain different amounts of water, and that tumors might have distinctive NMR signatures.

Raymond Damadian, an Armenian-American physician at SUNY Downstate in Brooklyn, made this connection. In March 1971, he published a paper in Science demonstrating that cancerous tissue produced different NMR signals than healthy tissue—specifically, the "relaxation times" were measurably longer. The paper became a Citation Classic. In March 1972, Damadian filed the first patent for an external NMR scanner, proposing that the technique could detect cancer throughout the body.

But Damadian's approach couldn't produce images—only measurements from specific body regions. The breakthrough to spatial imaging came from Paul Lauterbur at Stony Brook University. In September 1971, Lauterbur conceived of using magnetic field gradients to encode spatial information. By varying the magnetic field strength across the body, each location would resonate at a slightly different frequency. Computational reconstruction could then produce cross-sectional images. He published this insight in Nature in March 1973, demonstrating it with images of two water-filled tubes—modest but revolutionary.

Peter Mansfield at the University of Nottingham developed mathematical techniques to dramatically speed up image acquisition and improve quality. His "echo planar imaging" approach made real-time MRI possible and laid groundwork for functional MRI decades later.

Damadian raced to build the first human-scale scanner. On July 3, 1977, his machine—called "Indomitable," now at the Smithsonian—produced the first cross-sectional MRI of a human torso. Graduate student Larry Minkoff volunteered his body; the scan took nearly five hours.

The cascade from MRI transformed medical diagnosis. Unlike X-rays and CT scans, MRI uses no ionizing radiation. It reveals soft tissue with extraordinary detail—brain tumors, spinal injuries, torn ligaments, heart abnormalities. By 2026, over 100 million MRI scans are performed annually worldwide.

Recognition came with controversy. In 1988, Damadian and Lauterbur shared the National Medal of Technology. But in 2003, when the Nobel Prize in Physiology or Medicine was awarded "for discoveries concerning magnetic resonance imaging," only Lauterbur and Mansfield received it. Damadian was excluded. He took out full-page advertisements in major newspapers headlined "The Shameful Wrong That Must Be Righted," arguing that his cancer detection work and first human scan warranted inclusion. The Nobel Committee never explained the omission.

Path dependence favored superconducting magnet designs over permanent magnets, locking in high-cost, hospital-based installation. Alternative approaches like low-field MRI remained niche despite lower costs, because radiologists trained on high-field images and diagnostic protocols assumed that resolution.

By 2026, MRI remains essential diagnostic infrastructure. The bitter priority dispute between Damadian, Lauterbur, and Mansfield illustrates how foundational inventions emerge from multiple contributors—and how recognition can lag, exclude, or divide.