In trying to map complex nerve trees that control the back muscles of the human body, Dr. Aron Filler found that no matter where he turned in medicine or science, there was simply no way to "see" the nerves in the medical images of the human body.
After beginning his neurosurgery residency training in Seattle, Washington, Dr. Filler began work on the nerve imaging dilemma. His original plan was to develop a specialized nerve contrast agent. The idea was to use a biological phenomenon called "axonal transport" to transport contrast molecules into the nerves. He began the initial axonal transport project in Seattle in 1988. Two years later, Dr. Filler began a one-year clinical rotation in London, England, as part of his residency. It was during this period that big gains were made, when he began his MRI phase of contrast research that was funded by the Neurosciences Research Foundation at Atkinson Morley Hospital (AMH) in Wimbledon, famous for tennis event. Most of Dr. Filler's research was conducted at the "Father" Associated Road Hospital, St. George's Hospital Medicine Center in Tooting. There he had access to some of the world's most advanced medical research existing MRI systems. Surprisingly, while most of this work was done in 1990, the magnetic systems at St. George's remain well ahead of the most comparable systems to date.
Discussing his research with a Oxford University-trained physicist by the name of Franklyn Howe, Dr. Filler realized that he needed to try a slightly different direction. In late 1991 and early 1992 he created a new magnetic resonance pulse sequence strategy that would make possible to reliably identify a nerve in an image.
After a lot of thought about nerve biophysics and the complex physics of MRI pulse sequences, Dr. Filler came up with a radically unique pulse sequence strategy. It was based on the simultaneous suppression of the image signal from all other tissues, with the pulse sequence actually "squeezing" together a variety of different imaging strategies.
Further testing over the next few days confirmed the results: Dr. Filler's new pulse sequence had isolated the nerves on an MRI for the first time. Professor Griffiths, laboratory director and editor-in-chief of one of the leading academic MRI journals, agreed that this was a surprising advance in MRI technology - a pure nerve image without the need for a contrast agent.
Dr. Filler's pulse sequence required an extraordinarily advanced MRI scanner. However, the nerve imaging technique acted as a Rosetta stone; Now that nerves could be identified instantly and safely, Drs. Filler and Howe were able to quickly test a variety of other MRI sequences, each producing a similar effect. Within a week, they discovered a second sequence that had the potential to work on standard 1.5 Tesla clinical MRI scanners.
Shortly thereafter, Dr. Filler returned to his neurosurgical residency program in Seattle, where he asked Dr. Jay Tsuruda to test the new sequence on one of the 1.5 Tesla General Electric MRI scanners at the University of Washington Hospital. The first patient was filmed in November 1992 and the first spectacular image was produced. The picture seen around the world in the Lancet, the New York Times, and ABC News and CNN when it was published in March 1993.
