Siemens gets FDA nod on EPI sequences

Siemens Medical Systems of Iselin, NJ, has received Food and Drug Administration 510(k) clearancefor an upgrade package that brings faster echo-planar imagingrise times to its 1.5-tesla Magnetom Vision MRI scanner. The packagewill be available as a free upgrade to Vision scanners in thefield. It improves EPI rise times to 600 microseconds, comparedto 1200 microseconds on Vision's previous echo-planar sequence,which began shipping in November, according to Michael Sweitzer,product manager for MRI.

Rise times are the speed at which a scanner's gradients risefrom zero to maximum amplitude, which in Vision's case is fromzero to 25 mtesla/meter. Faster rise times help avoid respiratoryand blood-flow artifacts and are expected to improve Vision'sutility in future applications such as diffusion-perfusion imagingand functional imaging. Siemens is working on a hardware upgradeto Vision that will bring rise times down to 300 microseconds,Sweitzer said.