Featured History: Magnetic resonance imaging
When Nikola Tesla first described the rotating magnetic field in 1882, he could hardly have imagined what it would lead to. Just 130 years later, with the assistance of a paper napkin and a thin grad student, that discovery has become the basis for the highly popular tool of magnetic resonance imaging.
Like any major technological advance, the development of MR imaging was a drama with many actors. In 1937, Isidor Rabi, a physics professor at Columbia University, developed a method for measuring the movements of atomic nuclei — a state he decided to call nuclear magnetic resonance (NMR), for which efforts he was awarded the 1944 Nobel Prize in Physics.
At first, Rabi’s methods were used mainly to analyze the structures of chemical substances, but in the 1960s, a doctor named Raymond Damadian began to wonder if the same methods could be used on living organisms. In 1971, he concluded that since cancerous tissue contained more water than healthy tissue, it could be detected by scanners that bathed a part of the human body in radio waves and measured the emissions from the local hydrogen atoms. Now all that remained was the task of building a scanner large enough for the human body.
Around the same time, a chemist named Paul Lauterbur was hard at work using NMR to create images — first of vials of water, then of clams and green peppers. When he read Damadian’s 1971 findings, he realized that his work could have biomedical applications. He was the first to realize that a gradient magnetic field would allow observers to take two-dimensional images of an object, which could then be stacked to create a three-dimensional view — an idea he first sketched out on a paper napkin between bites of a Big Boy hamburger.
Meanwhile, in England, physicist Peter Mansfield was tackling the question of time, trying to find a way to complete scans in minutes rather than hours. By abandoning the usual “sensitive point scan” method and adopting a new technique he called “line scan imaging”, Mansfield was able to capture images of his grad student Andrew Maudsley’s finger in only 15–23 minutes per section, marking the first time that a human body part had been successfully scanned with NMR technology.
Mansfield’s next goal was a full-body scanner, and this was exactly what Damadian was busy constructing: a 1.5-ton machine called Indomitable, which leaked $2,000 worth of helium coolant per week. On May 11, 1977, Damadian donned the cardboard-backed antenna coil, slid onto Indomitable’s moving platform, and lay there while his assistants booted up the imaging systems … with no resulting image. After hours of adjusting the device, eventually someone suggested that perhaps Damadian’s body-fat content was too high. A thinner grad student, Larry Minkoff, volunteered to be the next guinea pig. He observed Damadian closely for side effects, and after seven weeks of seeing none, he climbed into Indomitable. Nearly five hours later, the team was rewarded with a two-dimensional image of Minkoff’s chest.
Eventually, Damadian’s methods were rejected as too slow for routine clinical use, and Lauterbur and Mansfield’s methods were adopted instead. For this success, Lauterbur and Mansfield were awarded the 2003 Nobel Prize in Medicine — a snub that Damadian felt keenly and called out in several full-page ads.
Modern MRI technology has undergone many changes since Lauterbur’s sketches and Damadian’s cardboard antenna. For one thing, early marketers decided to drop both Lauterbur’s preferred term “zeugmatography” (derived from the Greek word zeugma, or “yoke”) and the word “nuclear” from “nuclear magnetic resonance,” reasoning that this would allay people’s fears about radiation. Today, there are over 22,000 MRI units worldwide, which carry out 60 million exams per year, saving countless lives in the process.
To see copies of the first MRIs with further explanations and original sources, check out this page.
“Paul C. Lauterbur — Biographical.” The Nobel Prize Foundation. 2003. Web. 1 Dec. 2014.
“Paul Lauterbur.” The Economist. 4 Apr. 2007. Web. 1 Dec. 2014.
“Sir Peter Mansfield — Biographical.” The Nobel Prize Foundation. 2003. Web. 1 Dec. 2014.
“This Month in Physics History.” APS News. July 2006 (15:7). Web. 1 Dec. 2014.
Chang, Kenneth. “Paul C. Lauterbur, 77, Dies; Won Nobel Prize for M.R.I.” The New York Times. 28 Mar. 2007. Web. 1 Dec. 2014.
Maugh II, Thomas H. “Paul Lauterbur, 77; ‘The Father of MRI.’” LA Times. 28 Mar. 2007. Web. 1 Dec. 2014.
Wakefield, Julie. “The ‘Indomitable’ MRI.” Smithsonian Magazine. June 2000. Web. 1 Dec. 2014.
Nikola Tesla by Napoleon Sarony, via Wikimedia Commons.
Isidor Rabi from National Archives and Records Administration, via Wikimedia Commons.
Damadian’s device via Wikimedia Commons.
Sir Peter Mansfield via Wikimedia Commons.
Bush with 6 Nobel Laureates by Tina Hager, The White House, via Wikimedia Commons.