Evaluation of the Variability of the Maximum Expected Field Strengths in an MRI Room

This paper defines confidence intervals for the variability of the maximum expected field strengths, at the susceptible frequencies of 1.5T, 3T, and 7T MRI systems. Measurements of the maximum electric field were performed in a 30 m ³ MRI room. Based on the absolute values of the measurements, an analysis of the undermoded and overmoded properties of the room is presented. Then, the relation between the expected electric field, created by equipment characterized by its TRP, is empirically described. This relation is mainly characterized by the confidence interval of the maximum expected field strength. This confidence interval is a powerful tool to assess the severity of EMC risks.