SAFE-Model -- A new method for predicting peripheral nerve stimulations in MRI

Abstract

Modern MR-scanners can have high performance gradient systems capable to switch gradients of 30 mT/m and more in less than 300 ms. At this level new physiologic limits are set for MRI by the appearance of peripheral nerve stimulations when the gradients fields are switched very fast (as an overview see [1]). Whereas the sensation the patient feels is very weak when the stimulation threshold is reached, the magnetostimulations can become uncomfortable and even intolerable when the threshold is exceeded by about 50 % and more [2, 3]. This shows the requirement of an adequate supervision to prevent the patient from stimulations but allowing the optimum use of the system performance.