Stephan Maier is leaving his position at one of the world’s top medical universities and moving to Gothenburg and the Sahlgrenska Academy. The greatest attractions for him in Gothenburg are the major initiative taken with the Imaging and Intervention Centre (in Swedish: “Bild- och Interventionscentrum, BoIC”) and the opportunity for a cultural change for the family. He was appointed Professor in Radiology and Image Processing a few months ago.
Stephan Maier receives me in his corner office at Bruna Stråket, with a view across the extensive building site, where the BoIC building is taking form. He is surprised about the mild winter and the early spring in Sweden.
“I expected it to be cold. But in Gothenburg the cherry trees are already in bloom, while there is still 50 cm of snow on the ground in Boston”, he tells me with a half-smile, pointing out that the winter has been extreme both in Sweden and the US, but in opposite ways.
Stephan Maier was recruited to Gothenburg during the strategic and broad initiative that the Academy Board took to attract international top scientists. He took up his professorship as recently as December 2013, but has already found time to make many contacts.
“There is great expertise here and a strong will to develop research and the clinical application of magnetic resonance imaging (MRI). The conditions for research in Gothenburg are very favourable, and it is also worth remembering that there is a leading technical university here. The BoIC will provide infrastructure of international standing and greater capacity for research projects”, says Stephan Maier.
High-Tesla dreams
His clinical projects focus on the the development and optimization of MR imaging technology. This means not only developing new pulse sequences , i.e., the particular software that runs the complex magnetic resonance imaging machine, but also refining protocol settings that can be changed when imaging patients.
“Imagesobtained with MRI always have some background noise. The more we try to reduce scan time or visualize smaller details, the more noise and artefacts we get”, says Stephan Maier. (An “artefact” is a feature in an image that is not really present in the patient being imaged.)
The MR equipment uses strong constant and varying magnetic fields. The strength of the field is measured in “Tesla”, where higher Tesla numbers result in higher resolution and better signal-to-noise ratio. When examining patients, MR equipment with field strengths of 0.5 to 3 tesla are typically used, but significantly stronger magnets are available in experimental machines.
“Our dream is to bring a 7 Tesla machine here”, says Stephan Maier, but quickly to points out that right now this is just an improbable dream:
“The magnets are so expensive to manufacture that the only company that makes them has announced that they are ending production. But I hope that the manufacturing process can be improved and that 7-Tesla machines will be available at a more reasonable cost in the future.”
There is, however, a smaller 7-Tesla system available at Medicinareberget, suitable for examining small animals. There are plans to update this system, which Stephan Maier believes is an important step for MR research in Gothenburg.
Getting down to basics
Even though MR technology has been available for more than 30 years, much basic research remains to be done in this field.
“I think it is important to really understand what we see in the images, e.g., which part of the signal stems from the extracellular region and which part comes from the intracellular region. This is where quantitative experiments with small animals and simple models can teach us a lot.”
He is impressed by the standard at the Laboratory of Experimental Biomedicine (EBM) and other Core Facilities at Medicinareberget. He is particularly interested in future research collaboration with the NMR Centre.
Multilingual children
Stephan speaks Swedish surprisingly well, with just a slight accent. Not even when we discussabout his research does he need to switch to English. He explains that he lived in Sweden for some brief periods during his childhood, the last time when he was seven years old. His mother was of Swedish origin and kept the language alive for him as he was growing up. Now he has in turn passed on the Swedish language to his own children.
“I have eleven-year-old twin girls and they now point out when they think that my pronounciation of a place name in western Sweden is wrong”, smiles Stephan Maier. His wife is of Chinese background and she also has passed on her mother tongue to the daughters.
Two doctorates
Stephan Maier qualified as a medical doctor in Zürich in the middle of the 1980s and found himself strongly attracted to research. Within a few years, he had submitted not just one doctoral thesis, but two. The first was in medicine, the second in technology. His first thesis dealt with the then new magnetic resonance imaging technology; he compared how well this technology could measure blood flow in large vessels in comparison to ultrasound.
“Medical theses in Switzerland are not as extensive as they are in Sweden, but mine was unusually long according to Swiss standards,” says Stephan Maier, who spent nearly three years working on his first doctorate.
The second thesis, presented at the technical university ETH Zürich, also dealt with the new MR technology and various methods to measure motion in blood vessels and the heart.
Post-doctoral studies at Harvard
Since then his research has continued to centre around the use of MR to measure motion. Post-doctoral studies at Harvard Medical School brought him to Massachusetts, USA, where he continued to develop MR techniques. He became interested in a technique that appeared during the 1990s called “diffusion MRI”. The technique forms images from the slow and random motion of water molecules and has experienced a major breakthrough in clinical use and in research during the past 10 years. Today, for example, all cases of suspected stroke are examined with diffusion MRI.
“For a long time, only a few MR systems were available that could carry out diffusion MRI, and I didn’t have access to any of them,” says Stephan Maier.
Instead, he developed “line scan diffusion imaging”, a somewhat slower technique that can be used on standard MR systems, whileproducing images of high quality, unsurpassed by the current standard methods . His method was used for several years at Harvard Medical School and other hospitals for routine clinical examinations and for research.
Stephan Maier and his colleagues at Harvard also discovered how diffusion MR can be combined with advanced analysis to investigate brain tumours.
“This is a contribution to the palette of different contrasts that can be used when diagnosing brain tumours. It is a quantitative technique, and can be used to follow how treatment is progressing and determine whether it is working well or not,” says Stephan Maier.
New collaborations
He is continuing his work with diffusion MRI in Gothenburg. Even though he has only been here for a few months, he has already found time to start a collaboration to apply diffusion measurements in prostate cancer.
Stephan Maier is now winding down his work with his research group at Harvard Medical School, which consists mainly of established, senior scientists. For that reason, he is not bringing any colleagues with him to Gothenburg, but will establish a new research group here.
Images are not just a major part of Stephan Maier’s professional life, but also his private life. Photography is a great interest, both from a technical and an aesthetic point of view. In recent years, however, his focus has shifted from landscape images to images of his family and children.
Text: Elin Lindström Claessen
