If Alfred Nobel had lived a few decades later, there would certainly be a Nobel Prize for groundbreaking technological advancements. Luckily, the legacy of another visionary took on this task: During his lifetime, Werner von Siemens was convinced that science and technology are always going together thus triggering innovation and progress. Since 1916, the Werner von Siemens Ring Foundation has been honoring people who have greatly shaped and progressed the history of technology. The prize, a uniquely crafted ring for the recipient, goes to Max Planck researcher Jens Frahm from Göttingen this year. “With this ring, we are honoring the incredible achievements that Jens Frahm has accomplished for medical diagnostics,” explains Joachim Ullrich, President of the Physikalisch-Technische Bundesanstalt (PTB) and the Chairman of the Council of the Werner von Siemens Ring Foundation.
The triumph of magnetic resonance imaging
As a physicist, Frahm specialized in biological and medical applications early on. In 1982, he was already the head of an independent research group at the MPI for Biophysical Chemistry focusing on MRI. When Paul Lauterbur invented MRI in 1973, it had a major drawback: It was too slow. As a consequence, the promising idea of producing images from inside the body without dangerous radiation and excellent soft-tissue contrast did not really catch on at that time. The technology is based on a combination of a strong magnetic field and radiofrequency waves in the FM range. When a human body is placed within a magnet, the MRI 'tube', the nuclei of hydrogen atoms act like small magnets themselves which respond with their own radiofrequency signal when excited by a short radiofrequency impulse. This signal is measured many times with slightly different 'views'. Using this information, images of soft body tissues can be calculated. However, several minutes were required for each section in the beginning.
Frahm had the crucial idea to only use part of the available MRI signal for each of the numerous repetitive measurements needed for an image. With this physical trick – the FLASH method – he was able to completely eliminate the pause previously required for signal recovery. This radically reduced the measurement time by a factor of 100 and was the breakthrough in MRI. Nowadays, the technology is used to answer all types of questions: Does a person have tissue abnormalities in the brain? Does an accident victim have internal injuries? Is there a herniated disc? Has a heart been damaged – structurally or functionally?
Filming the beating heart
In 2010, Frahm and his team opened the door to MRI videos by massively accelerating the method again. FLASH 2, the step towards real-time MRI, is based on a new mathematical procedure for image reconstruction which now may be accomplished with only a very small number of repetitive measurements and, therefore, much shorter measuring times. Film recordings of a chest during free breathing, of a beating heart – even for patients with cardiac arrhythmias, of joints at work, or of complex processes such as speech or swallowing are now possible – at 30, 50, or even 100 images per second. In future, the new technology will also be used as a tool for monitoring minimally invasive interventions replacing conventional X-ray controls. Real-time MRI is currently being tested for routine clinical use at the University Medical Center Göttingen as well as several other universities in Germany, Great Britain, and the United States.
Source: Press release Max Planck Institute for Biophysical Chemistry