THE world鈥檚 most powerful MRI scanner was unveiled this week at the University of Illinois in Chicago.
The scanner has a 9.4-tesla magnet, six times as strong as the magnets in hospital scanners. Whereas standard scanners pick up signals from the hydrogen atoms in water molecules, high-field-strength scanners can resolve signals from other elements such as sodium, phosphorus, carbon, nitrogen and oxygen. This means they can reveal far more information about living bodies. The Chicago team, led by Fred Thulborn, hopes to gain new insights into brain disorders such as strokes, Alzheimer鈥檚 and autism. There are concerns about safety, though. One study found that mice exposed to a 14-tesla field ran around in circles for several minutes afterwards, among other things (New 杏吧原创, 18 May 2002, p 12). 鈥淲e have to balance the useful information you can get from high magnetic fields with the possible dangers, which we just don鈥檛 know,鈥� says Peter Mansfield of the University of Nottingham, UK, who won a Nobel prize last year for his work on MRI technology.