In the vast archives of the Smithsonian's National Museum of American History resides the title of ownership to a machine named Indomitable that represents a milestone in the history of medical imaging. Its story is a timeless one of a driven inventor who perseveres through every obstacle only to find that others are racing along similar paths, which in this case led to today's ubiquitous magnetic resonance imaging (MRI) machines.

Columbia University professor Isidor I. Rabi first observed the quantum phenomenon dubbed nuclear magnetic resonance (NMR) in 1937. He recognized that atomic nuclei betray their presence by absorbing or emitting radio waves when exposed to a sufficiently strong magnetic field. Within a decade of Rabi's discovery, chemists and physicists had adopted NMR as a standard analysis for substances. But 30-some years would elapse before anyone even considered using the method to scan a breathing human body for cancer.

Enter Raymond Damadian. An experimenter at heart, he brought a fresh perspective to NMR — that of a physician. He had earned a medical degree at Albert Einstein College of Medicine in the Bronx and pursued his medical research career at Brooklyn's Downstate Medical Center.

Damadian's first foray into the field of imaging began when, during a postgraduate stint at Harvard University, he experienced excruciating abdominal pains. Doctors detected nothing using x-rays or other conventional methods short of surgery. Damadian decided a better way must be found to examine the inner workings of the body.

The proverbial lightning bolt struck Damadian in 1969, after he used an NMR machine to investigate his ideas about electrically charged particles in the body. His associate Freeman Cope, a Navy physician and physicist, brought him to a small company on the outskirts of Pittsburgh where the two measured potassium, a common electrolyte, in a strain of Dead Sea bacteria.

At breakfast a few mornings later, Damadian wondered aloud about what would happen "where you have an antenna wrapped around the human body, where you can look at an atom, and then another atom, and then another atom — you could go from one tissue to the next and, without ever invading the body, get the chemistry of each organ." Even Cope thought Damadian's idea far-fetched, but Damadian committed himself to the quest.

In 1970 Damadian returned to test cancerous liver samples from rats with the NMR equipment. On the basis of his electrolyte work, he surmised that the hydrogen signal in cancerous tissue might differ from that of healthy tissue because tumors contain more water. More water meant more hydrogen atoms — two per water molecule. Once the bath of radio waves was switched off, telltale emissions from the cancerous regions would linger longer than those from the healthy, less aqueous regions. It worked. The journal Science published his findings in March 1971. Cancerous tissues could now be detected in humans without resorting to radiation, he reasoned, if a large-scale scanner could be built.

Later that same year, Paul Lauterbur, a chemist and NMR pioneer at the State University of New York, Stony Brook, conceived of a way to use NMR to produce an image. His idea, documented in a notebook, entailed using magnetic field gradients to map out a series of points. In 1973 Lauterbur produced the first NMR image of a small amount of water in a test tube, a feat he published in the journal Nature. Soon after, he imaged the first live subject: a tiny clam.

Though Lauterbur's gradient approach quickly gained favor over Damadian's human scanner method, Damadian filed for a patent on his concept in 1972 and received it in 1974. He forged ahead, determined to make the first human scan. Aided by graduate students, he built the heart of Indomitable, a homemade superconducting magnet, from roughly 30 miles of niobium-titanium wire wrapped on a cylinder. The magnet, a hollow cylinder, spanned 53 inches in diameter, big enough to swallow up a human. On top, the team installed an elaborate liquid helium cooling system to keep resistance in the wire near zero. But the helium leaked miserably, costing $2,000 a week and reducing the magnet's strength.

Without time for modifications, Damadian pushed his team onward. Mike Goldsmith, one of his graduate students, cobbled a wearable antenna coil fashioned from cardboard, capacitors and copper wire. Others fine-tuned the rest: an oscilloscope to monitor the hydrogen broadcasts detected by the coil; a minicomputer to translate the received signals into an image; and a manually operated wooden platform to move the subject. Damadian's moment of reckoning finally arrived on May 11, 1977. Inside his Downstate Medical Center lab, he ran through his checklist, a process that took about 12 hours.

Approval from the school's Human Experimentation Committee seemed unnecessary. Damadian had volunteered himself as the first guinea pig.

With veiled trepidation, Damadian shimmied into the corsetlike antenna coil and sat down on the movable platform inside his shiny, 1 1/2-ton contraption. Without fanfare, Damadian's assistant powered up Indomitable's systems and subsystems.

Seconds passed. Then minutes. The team couldn't detect any radio signal. A half-hour passed. Still no signal. After hours of tinkering, still nothing. "We were very depressed," Damadian recalls. "We had been telling the whole world that we were going to be able to do this thing and we failed."

Eventually the thought occurred that Damadian might be too corpulent for the feeble coil. Apparently fat insulates the body from more than mere cold weather.

For seven weeks after the test, graduate student Larry Minkoff keenly monitored his boss, watching for any odd behavior or ailment. Detecting none, he offered his own svelter torso to science.

The machine appreciated his lean physique. On July 3, 1977, nearly five hours after the start of this test, Indomitable achieved the first human scan and became the first MRI prototype. The crude image, reconstructed first with colored pencils and then by computer from 106 data points, revealed a two-dimensional view of Minkoff's chest — including his heart and lungs.

Damadian trumpeted Indomitable's success to the media, asserting, perhaps a bit rashly, in a July 20 press release that "a new technique for the nonsurgical detection of cancer anywhere in the human body has now been perfected."

A year later, he founded a company to commercialize the technology. Named for his field focusing approach, the Fonar Corporation marketed its first product in 1980, based on the Indomitable prototype.

Today, Indomitable, minus its electronic subsystems, is prominently displayed at the National Inventors Hall of Fame in Akron, Ohio, on loan from the National Museum of American History. The Hall of Fame inducted Damadian in 1989. A year earlier, Damadian shared the National Medal of Technology with Lauterbur for their independent contributions to MRI technology.

The use of MRI technology, of course, has spread so rapidly that nowadays even dogs and cats benefit from its revealing scans. Improvements to MRI machines have even made it possible to trace thought or perception sequences for brain research.

Despite the technology's success, detractors denounce the first Indomitable image as "meaningless," given its crudeness and vulnerability to bias. Moreover, they view Damadian's so-called breakthrough as a technical dead end: even his own company, Fonar, abandoned the approach and adopted Lauterbur's in the early 1980s. But Damadian considers Fonar's courtroom victory in 1997 over General Electric, which forced the industry giant to award him $128 million for patent infringements, as proof of the priority of his concept.

Raymond Damadian now is racing other experimenters to create a giant MRI machine that will allow surgeons to view patients' interior anatomies while they operate. Historians of science, meanwhile, will review the history of MRI technology to distinguish braggadocio from brilliance, as tough a task as measuring spin on electrons. If claims hold up, someone from the field may again make headlines — as a Nobel Prize winner.

By Julie Wakefield