Paul Lauterbur and the Invention of MRI

by M. Joan Dawson

  Interest in Neuroscience

  In the late 1980s Paul started bringing home a lot of books on neuroscience, cognitive science, and psychology. Hmmm . . . , I wondered. Paul waxed grandly in conversations about philosophy of the human mind and at the same time asked me precise questions about neurophysiology. He mused about human and animal will and consciousness. Could the whole continents with their underlying structures that move around the Earth share our illusion of free will? I thought the free will of continents was just silly, but Paul kept at it. Could will and consciousness be incorporated into artificial structures like computers? Could they be incorporated into other natural structures as well? He quoted Buddha, in the Way of Purification, that people must “Train their minds and keep them broad as the earth, unlimited as the sky, deep as a big river, and soft as well-tanned leather.”

  And I learned just a few days before the deadline for a large grant application to the Research Resource Division of the National Institutes of Health (NIH) that we were going to ask for an enormously expensive, clinically capable MRI system because we wanted, among other things, to study neuroscience. This was beyond funny. These large grant applications, several hundred pages long, can take more than six months of slavery to produce. Moreover, the funding agency simply didn’t have that kind of money.

  The grant was peer-reviewed by scientists who came to our site to look us over and ask questions. Awkwardly, the very night the reviewers began arriving an article appeared in our local Champaign News Gazette stating that Mercy Hospital would be tearing down the building in which we were housed to create space for a hotel and restaurant complex. The agreement between the hospital and the university for that space was simply ignored; they intended to break the contract. We were doomed! Nobody in their right mind could recommend funding for us under these circumstances. Mort Weir, then chancellor of the university, came to our rescue. He came before the review committee and committed university support in no uncertain terms. “We consider Paul to be a national treasure,” he said. We obtained the grant, but at a very low funding level. (“Don’t start spending it wildly,” Paul cautioned.)

  Paul laid grand possibilities in front of the neuroscientists: Seiji Ogawa had recently shown in animals that an MR image changes with blood oxygenation. Paul was sure we could monitor brain activity by these image changes because active neurons use oxygen. The technique was to become known as functional imaging. And we could trace nerve fiber bundles by another developing technique, diffusion tensor imaging. Plus we could image important metabolites. All of this would indeed come to pass during the next twenty years, but it was a breathtaking stretch at the time. The gold standard for studying brain metabolic activity was then positron emission tomography (PET), but MRI could yield more versatile information less expensively. (I have often been grateful to the practitioners of PET; their technique is the only one I knew in biological and medical sciences that was more expensive than ours.) With MRI, Paul told his credulous listeners, you could study the effects on the brain of any number of long- and short-term interventions into the workings of the mind. He was so excited about this potential that he neglected to mention how much technical development would be required to bring the future to us.

  Figure 9.4

  Paul’s ideas of what could be done with brain imaging, c. 1990.

  The neuroscientists, believing all of this magic was immediately possible, that Paul would get them a machine and they could push a few buttons and come out with exciting data, were frustrated and turned nasty once they learned the hard reality. Had Paul’s efforts at collaboration with the neuroscientists on campus come to fruition he may have led important MRI developments in neuroscience and cognition. They thought him not only disastrously slow in adapting the technology, however, but also an invader on their turf. But there were other ways to advance his scientific interests.

  “Last Chance, Sisyphus!” The 4 T Whole-Body Magnet

  In keeping with its new director’s controversial goals of funding research in innovative ways via groups, centers, and major facilities, the National Science Foundation announced a multi-institutional Center Grant Program to begin in 1990. It seemed made for Paul. It required an ambitious technical development plan and its application to the most interesting and important scientific problems of the day. Paul chose as his research question, “How does the brain work?” The enthusiasm was palpable. In addition to our own institution, Seymour Koenig of IBM was to consult on relaxation effects in the brain, and David Levin of the University of Chicago was to work with us on metabolite localization. Tom Budinger of Berkeley was to study human physiology. Paul was to work with Russ Houson of the Texas Accelerator Center (TAC) to build a 4 T shielded MRI whole-body magnet. It was a technological adventure.

  A what? Paul had always been enthusiastic about going to the highest fields possible, and since his earlier 10 T project had not got off the ground, he asked for a 4 T magnet, the cost of which would fit within the funding parameters of the grant. This was nearly three times the field strength of common clinical magnets in use today. But high magnetic fields for MRI present a unique problem: the magnetism spreads out way beyond the magnet itself. In the case of the 4 T it would extend throughout the five-story Beckman Institute, where our magnet was to be housed, and would cross a major avenue in front of the building. Hence the need for magnetic shielding. The magnet would be wrapped in 150 tons of iron housing to suck in the fringe field to within a few feet of its center. Russ and TAC had plenty of experience with big magnets for other purposes. As reported in our local paper, the Texas people “realized they could solve a problem about magnet design that people building magnets for magnetic resonance imaging had thought could not be solved. When they realized this, they looked for opportunities to use this new insight in a different field.”5

  So with the new technology development of the shielded magnet and an application to neuroscience during the Decade of the Brain, as the 1990s were designated, our project had pizzazz. We were successful, and were designated an NSF Science and Technology Center, one of only fourteen in the country. We had hit all the right buzzwords, and people around the University of Illinois were pretty high on us for a while. Eventually there were three NSF centers on our campus, more than any other university had. The top-tier administrators were self-congratulatory, maybe rightly. There were gasping write-ups in local and university papers.

  But our funding was cut direly, and we got only $6.8 of the $20 million I had calculated we would need to run such a center for five years. With this we could build the magnet and maintain it if everything went right (and things never go right), but do no research. I was terrified. I had put that budget together, and I knew there was no fat in it. And the money was to be distributed in equal amounts over a five-year period, while most of the funds were needed up front for building the magnet.

  I told Paul it was impossible and we shouldn’t accept the grant. He rejected this warning at once. “But this is my last chance. I invented MRI, but I’ve never had a whole-body system to work with, and if I throw this opportunity away I will never have one.” Paul won the argument (by fiat). From the day the application for the 4 T was funded, the lab was run in continual crisis mode.

  The magnet was built at the TAC in Houston, supposedly under the direction of Russ Houson. But something happened there politically, in part connected to this difficult 4 T magnet-building project, and Russ went into retirement. After that, no one seemed to be in charge. Important decisions were left to the technicians building the magnet, when more senior input was needed. The parent body of TAC threatened at regular intervals to fire key people.6 The project ran behind schedule and the NSF was pushing us about its completion, threatening to cut off our funding if it didn’t ship soon.

  The shipping of the magnet was a grand affair, with our local newspapers covering the story as the magnet was driven from Texas to Urbana-Champaign. All was congratulatory; all was celebratory. But the magnet that arrived was r
eally a potential magnet. It had no magnetic field. To make it a functioning magnet, the windings of niobium/titanium wire had to be exposed to near absolute zero temperature, at which point they would lose all electrical resistance and become superconducting. Liquid helium has a boiling point of 2°K in a vacuum,7 close enough, and liquid nitrogen was used to pre-cool the magnet down to its boiling point of –196°C, thus conserving the more expensive liquid helium.

  The weeks leading up to the 4 T’s filling with liquid nitrogen and liquid helium were replete, organized, and chaotic. Much of the burden fell on Carl Gregory, on whom we relied for so many things, who was designated to lead the group. We gave him a Russian army captain’s hat that Paul had found in a catalogue. Doug Morris and Ken Ghiron were also designated as team leaders, although both, especially Doug, had many other duties as well. We all worked and worked and worked, as if for a war we were all determined to win. The longer the hours, the more problems we faced and solved. The worse the odds, the more bonded and united we all became.

  At last the time for the filling with expensive liquid nitrogen and even more expensive liquid helium to cool the magnet to 2°K, close to the point of cessation of all energy. We worked around the clock in shifts, but the magnet wouldn’t cool! We poured more and more of that freezing money into it, we way surpassed our budget for liquid nitrogen, and still the magnet couldn’t cool. Paul posted a cartoon of an ancient Greek rolling a rock up a mountain. He captioned it “Last chance, Sisyphus!”

  Figure 9.5

  “Last chance, Sisyphus!”

  To try to figure out why the magnet wouldn’t cool, Paul was reduced to pondering college textbooks about supercooling. At last, after a week and $150,000 of nitrogen and helium, we reached the magic number. The magnet was supercooled, and electrical resistance was all but eliminated. This mass of unimpeded wire encased in steel and surrounded by its 150-ton iron jacket was rendered superconducting. But it was not yet a magnet. For this it needed injection of an electrical current into the superconducting wire.

  On January 15, 1994, Carl Gregory began the current injection and rise in magnetic field, wearing his USSR captain’s hat. This would take several hours. All was calm, quiet, and respectful as the magnetic field slowly ramped up. The magnet would either make field or not, and it could be destroyed in the process. Imagine a NASA liftoff. The room was huge, and there were very few of us in it. There was some quiet talk and a little quiet laughter, not hilarious laughter but that of serious people relieving tension. The only really audible sounds were Doug periodically calling instrument readings to Carl, and Carl repeating them back for accuracy as they were logged. At 11 p.m. the magnet reached 2.5 T. It was performing superbly.

  Just as the psychological tension began dissipating, we heard something. A loud clunk. A hissing of much gas escaping. Somewhere in all those miles of wire a short circuit had occurred, rendering the magnet suddenly nonsuperconducting and too warm to contain the liquid nitrogen and helium. Doug read the magnetometer: down, down, down, zero.

  Failure. We heard liquid nitrogen raining outside. The failsafe mechanism had conducted the liquid outside, where it evaporated harmlessly. Had that mechanism failed, the nitrogen would have spread out in the room, displacing oxygen, and we all could have suffocated. A technician from TAC did leave the room at the time of greatest danger and came back some twenty minutes later, when all was over. “I went outside to see if the nitrogen was escaping properly.” The others good-naturedly mocked him. “Oh yea, you just ran away and left us all to our fate.” Our daughter put a Band-Aid on the big magnet.

  Paul sat in his library chair all night, nursing a whiskey and napping, his head askew, fitfully. Paul’s accomplishments and identity were one and the same, and he was deeply disappointed in himself. Grimly, he got ready for work the next day—to begin the damage control. The immediacy of failure shriveled the importance of all his past accomplishments—to himself and to the university. He had been pursued, as sung by the bard, by fanged and furious misfortune. He had taken a huge blow and staggered under its weight, but he was not defeated. As he began damage control, he showed only his usual calm sense of duty and absurdity. “Pity,” Paul joked, “we didn’t have any balloons to blow up.” All that helium could have been put to good use. He also told a local reporter, with understated calm, “When the 4 T project failed . . . that is a big piece of the program (the NSF grant) that was stopped dead in its tracks.”8

  We had a party for everyone involved, and decorated the house with black balloons. It was the end of all we had worked for. Eventually we had the luxury of once again fretting about little things.

  Nukin’ the BMRL

  Blood was smelled. A group of scientists at the Beckman Institute decided they must, for the good of the university, wrest control of the BMRL away from Paul. Or as one of them put it to me in a rare personal conversation, they were “working to promote their own self-interests,” an endeavor that apparently required that they “get Paul.” They wanted to take over the lab, all the equipment, and the center grant. And they didn’t waste any time. The same week the magnet failed, a trip was made to the NSF to talk to Mary Clutter, director of biology, about it. They suddenly found that some of our equipment actually belonged to them. To me they looked like Darwin’s cats: they “stand at full height, and arch their backs in a well-known and ridiculous fashion . . . the hair . . . becomes erect . . . to make themselves look as big as possible.” They probably thought Paul was so down and out that the takeover would be easy, but he doggedly continued the effort to do his duty in a bad situation. He continued to try to come to some accommodation with his former colleagues, now his sworn enemies. Nothing worked.

  The laboratory notebooks at TAC showed that a joint in the wiring was known to be bad. Instead of unwinding the wire to the bad joint and fixing it, the TAC technicians had short-circuited the bad spot. Expedient, but unsafe. It was apparently at this short-circuit that the magnet first failed and, in doing so, was knocked two full inches into its iron shield, causing the sudden and catastrophic damage. There followed a lawsuit, the University of Illinois alleging negligence on the part of TAC, and TAC claiming that all of the pressure Paul was putting on them for speed was the basic reason for the failure. Paul was indeed pressuring them because the NSF was threatening to cut off funding if the magnet wasn’t ready soon. The NSF was being pushed by Congress to fail a few of their centers, and ours was the ideal target. We were closed.

  With the loss of the NSF center, Paul lost his position at the Beckman Institute, and in a complicated chain of events was eventually forced out of the Medical School and had to give up his personal laboratory and equipment. It was the worst disaster imaginable; his fall from grace was complete. Today magnets with iron yokes for shielding are commonplace.

  There seemed to be a sociological disease, a social mania going on in which Paul became the scapegoat for everything. Why? I began to think there was something in the drinking water at the Beckman Institute that unhinged people. A colleague who attended their meetings told me “They call a meeting. They sit around and talk, and most of the meeting is griping about Paul. Some of their complaints have a germ of truth in them but most have no basis at all.” Like political attack ads, they were low and mean and effective. Paul was so bad-mouthed that people meeting me for the first time (not knowing me to be Paul’s wife) would talk about that horrible man, Paul Lauterbur. These were people who had never met him, had not had any interaction with him, who knew nothing about him personally but that he was a terrible man. Paul’s reaction to all of this was puzzlement and stoic grief. Mine could be described as a nervous breakdown.

  In the late 1990s, when Paul was in his late sixties, the biomagnetic resonance building, Paul’s office, laboratories, staff and all of our equipment—including that provided from university funds in 1985 as a start-up package and those items purchased from external grants over the years—were transferred to the Beckman Institute. Paul was forced out of the Medic
al School, and he was never able to do MRI again. While Paul showed little emotional reaction to the stress, it came out in a series of small strokes, the onset of diabetes, hypertension, and diverticulosis—all-stress related diseases. He had invented the tool for his own diagnosis; MRI showed that he had been having mini-strokes for some time. His body was falling apart around him and his illnesses became fierce and deadly opponents, which he faced without a trace of self-pity.

  Diverticulosis brought him near death. Paul always abhorred infirmity, and refused to trust doctors or medical assistance of any kind. “I invented MRI because I hate x-rays,” he told me irascibly. When his physicians explained to Paul that he would need to have a large portion of his colon removed, he refused. No heroic treatments, he said; his time had come. The doctors closed the curtains around his bed and left us to discuss it, me near hysteria and him stubbornly refusing to listen. All the while nurses were coming in to check this and that, and even the cleaning staff couldn’t be put off.