Seven Tesla

The University of Pennsylvania became the proud owner of a Siemens 7T MRI system on Saturday. The magnet weighed in at a trim 36+ tons and was secured to 4 rigs each capable of holding 15 tons. The magnet arrived on a flatbed truck after being delivered on a ship from Germany. Check out the press here.


For nearly an hour, the riggers eyeballed the system of chains and platforms used to secure the device. Slowly the magnet creeped toward a hole where it would be lowered into the basement of labs where the MMRRCC facility is located. As the magnet approached the hole, the chief rigger decided the track along which the magnet rode was not secure. The magnet was brought out, the harness was secured and the creep continued. Each side of the magnet was lowered manually and asynchronously from the ground floor to the basement of Stellar-Chance. There was some (small) risk that overloading a single 15 ton capable pulley could send the magnet plummeting 20+ feet. Here is a view from the basement as the magnet is lowered from the ground floor.


So why 7T? There is a strong desire among researchers to acquire images at 7T because of the better resolution, the ability to separate resonances in separate chemical environments and changes in relaxation times. Several sites in the country have already installed full-body 7T or greater MR sytems, including OSU and UCSF.

It should be another 2 months before the magnet is ready to be used for research. And besides the magnet itself, RF coils need to be manufactured for nuclear excitation and image acquisition. Two such coils, designed for both proton and sodium imaging, are already in the works for the Penn site.