Validation of Noise Figure Measurements by Means of MR Imaging

Jurek A. Nordmeyer-Massner¹, Klaas P. Pruessmann¹

The noise figure of a preamplifier reflects the amount of noise added by this device and must be strictly minimized for MRI detection. A refined method for noise figure measurements at MR frequencies has recently been described. The aim of the present work was to cross-validate this method by means of actual MR measurements. This is achieved on the basis of an extended model of noise superposition along an MR systems receive chain, permitting to track the preamplifier contribution. It is shown that noise factors thus calculated from image SNR agree very well with bench measurements of the noise figure.