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  • MR


The Hubble Telescope of Brain Research

Neurologists are exploring the deepest areas of the brain. New and extremely powerful magnetic resonance tomo- graphs make it possible to not only observe individual living cells as they work, but also monitor the path that biochemical molecules travel through the brain.

A 7-tesla MR tomograph enables researchers to identify even very weak signals from within the brain. In the future, scientists will be able to observe how medications work.

T he university hospital in Magdeburg, Ger- many, is home to one of the world’s most powerful magnetic resonance (MR) tomo- graphs. The magnetic flow density in the de- vice’s interior measures seven tesla, which is 140,000 times stronger than the Earth’s mag- netic field. The colossus weighs 32 metric tons and consists of a superconducting niobium-tita- nium wire that is 400 kilometers in length, but which is rolled up into a coil and cooled to minus 269 degrees Celsius. This 7-tesla MR machine is the first of its kind in Europe and one of only six in the world to date (three of which were built by Siemens). Siemens Medical Solu- tions delivered the unit to the Leibniz Institute for Neurobiology (IfN) in February 2005. “The technology had already proved its value in day- to-day clinical operations, which is one reason why we decided to go with Siemens,” says Dr. André Brechmann, head of the Noninvasive Imaging lab at IfN. “We were also able to take a look at a functioning reference unit at Massa- chusetts General Hospital (MGH) in Boston.”

Researchers in Boston have been using their 7-tesla MR machine — the first ever supplied by Siemens — for three years now (see p.62 for a description of how magnetic resonance works). Dr. Lawrence Wald, who is responsible for scan- ner facilities at MGH, is thrilled with the possi- bilities the 7-Tesla machine offers, and de- scribes the scanner as “the Hubble telescope of brain research.” Researchers at IfN are also ex- pecting great things from their new ultra high- field MR tomograph, which they plan to use for basic research and for early and reliable diagno- sis of diseases such as Alzheimer’s, epilepsy, schizophrenia, and multiple sclerosis. The de- vice’s high spatial resolution enables doctors to identify even the tiniest changes in tissue.

“When you look at the very first images of the brain taken with the unit, you can see de- tails measuring less than a tenth of a millime- ter,” says Brechmann. It will also be possible to use the scanner to monitor thinking processes in near time in areas of the brain with a volume of less than one cubic millimeter. “This will en- able us to observe for the very first time even relatively small functional units in the cerebral cortex as they go about their work,” Brechmann explains. Among other things, he and his col- leagues will attempt to find out how the brain processes acoustic signals — for example, by determining which regions of the brain process subliminal emotional messages in spoken sen- tences. “Our goal is to make a comprehensive map of the functioning of the human brain,” says Brechmann.

Researchers and physicians at IfN also plan to use a technology known as spectroscopy to

examine brain metabolism and determine which biochemical substances play a role in var- ious diseases. One thing they will attempt to find out is whether the neurotransmitter GABA (gamma-amino butyric acid) contributes to the development of schizophrenia, as many neurol- ogists suspect.

Using spectroscopy, they hope to be able to identify those areas of the brain actually af- fected by medications used to treat neurologi- cal diseases. The higher the strength of the to- mograph’s magnetic field, the easier it is to differentiate between various substances. Whereas GABA can be identified only with great effort using a special procedure on a 3-Tesla MR machine, it can be easily quantified with a 7-tesla scanner by means of a standard meas- urement procedure.

In order to further improve MR’s diagnostic possibilities, Herbert Thein, Siemens project manager for the development of the 7-tesla scanner, is working with colleagues in Erlangen on creating new gradient and high-frequency coils that will be specially adapted to 7T’s unique physical parameters. As such, the next- generation 7-tesla machines will have 32 radio frequency channels instead of the previous one or eight. “We’ll then be able to more precisely determine the location in the brain from which a signal originates, which in turn will lead to higher resolution images,” says Thein, who is delighted with demand for the new devices. “Nine next-generation 7-tesla scanners have al- ready been ordered,” he reports.

The race to achieve even higher field strength is already under way again. CEA (the French Atomic Energy Agency) has launched the “Neurospin” project to promote the simulta- neous development of medical imaging sys- tems and specific types of contrast agents for neurological examinations. The ultimate goal here is “molecular imaging” — the depiction of individual cells as they go about their work. The core focus of the project is the development of an 11.7-tesla scanner. “Such a unit should be feasible in the next five years,” says Dr. Robert Krieg, head of the working group for Molecular MR Imaging at Siemens, who has already con- ducted a feasibility study with his team on be- half of the CEA. Krieg is certain that advances expected to be achieved through development of such a super magnet (e.g. improved cooling, new materials, a more simplified radiation pro- tection system) will also improve today’s stan- dard lower field strength MR scanners, even in terms of image interpretation. As Krieg points out, “You learn an unbelievable number of t h i n g s w h e n y o u r e w o r k i n g o n a p i o n e e r i n g U t e K e h s e project.”

In Brief

  • Information technology and networking are

essential tools for improving the quality of health care while cutting costs. That’s why the use of digital technology in health care will con- tinue to increase. Software is already an indis- pensable aid in the medical field, since it opti- mizes clinical work processes and information flows and ensures that the right information is available at the right place and at the right time. Whereas hospitals have invested primarily in administration and billing systems over the last few years, the focus in the future will turn to procurement of information technology for medical processes. Europe has high hopes re- garding electronic health cards and doctors’ networks. (p.75, 76, 80, 83, 84)

  • Computers support doctors with diagnoses

and treatment planning. Siemens solutions are providing valuable assistance for identifying cancer at an early stage. For example, auto- matic image processing systems can recognize very small lumps in the breast, colon and lungs. “Virtual flights” through the colon enable doc- tors to identify polyps that might be missed using conventional procedures. In less than 20 years, automatic cancer identification systems may advance to a point that will make biopsies of suspicious lumps unnecessary, while intelli- gent diagnostic systems with access to data- bases will help doctors make decisions. (p.66)

  • Digital technology also offers tremendous

benefits when it comes to treating illnesses. For example, magnetic navigation systems for car- diac catheters allow cardiologists to precisely maneuver through small blood vessels by means of a joystick in a manner that makes it possible to get around even the narrowest curves — and such navigation can even be conducted automatically. In what would amount to a medical sensation, such systems may relieve patients of the trauma of bypass operations in the future. (p.70)

  • Medical imaging devices deliver huge

amounts of data from which computer programs can create detailed images of the inside of the body within seconds. Merging technologies (such as CT and PET) into hybrid devices improves image quality and simplifies diagnoses. And because special software can rapidly and precisely compare the images recorded during different examinations, the use of such hybrids also makes it easier to monitor the course of treatment. Ultrasound examina- tions with newly developed devices can even provide doctors with moving 3D images. (p. 72)

PEOPLE: Computer-assisted diagnosis: Dr. Alok Gupta, Med alok.gupta@siemens.com Dr. James Williams, SCR jimwilliams@siemens.com Dr. Sriram Krishnan, Med sriram.krishnan@siemens.com Computer-assisted therapy: Arne Westphal, Med arne.westphal@siemens.com Dr. Wolfgang Nitz, Med wolfgang.nitz@siemens.com Michael Martens, Med michael.martens@siemens.com Hybrid devices: Keith Andress, Med keith.andress@siemens.com Stefan Käpplinger, Med stefan.kaepplinger@siemens.com Gerhard Kreitz, Med gerhard.kreitz@siemens.com Health card in Lombardy: Maurizio Michi, Siemens Informatica maurizio.michi@siemens.com Health card: Werner Braun, Siemens Com wernerbraun@siemens.com Electronic patient file: Martin Prätorius, Com martin.praetorius@siemens.com IT for hospitals: Deng Li, Med (Sienet, China) li.deng@siemens.com Robert Dewey, Med (THCI, Cardiology) robert.dewey@siemens.com RFID in hospitals: Thomas Jell, SBS thomas.jell@siemens.com 7-Tesla MRT: Herbert Thein, Med herbert.thein@siemens.com Dr. Robert Krieg, Med (Mol. imaging) robert.krieg@siemens.com Leibniz Institute for Neurobiology: Dr. André Brechmann brechmann@ifn-magdeburg.de www.ifn-magdeburg.de

LINKS: Siemens Medical Solutions www.medical.siemens.com MGH Martinos Center: www.nmr.mgh.harvard.edu/martinos European Commission, ICT for Health: europa.eu.int/comm/dgs/information_society OpenClinical: www.openclinical.org

Pictures of the Future | Fall 2005


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