The use of multiple physiologic parameter regression increases gray matter temporal signal to noise by up to 50%
Birn R, Murphy K, Bodurka J, Bandettini P
National Institute of Mental Health
The temporal signal-to-noise ratio achievable in T2*-weighted MR imaging time series is limited by physiologic noise. The goal of the present study is to compare and evaluate the effectiveness of five additive physiologic noise corrections: 1) RETROICOR to reduce fluctuations at cardiac and respiration frequencies, followed by regressing out 2) respiration volume changes, 3) motion parameters, 4) global signal average, and 5) the average signal over white matter. We found that in addition to more conventional physiologic correction routines, regressing out estimated motion parameters and slower changes in respiration volume lead to TSNR improvements of up to 45% gray matter.