Gisela E. Hagberg1, Marta Bianciardi2, Valentina Brainovich1, Bruno Maraviglia3
1Santa Lucia Scientific Foundation, Rome, Italy; 2LFMI, NINDS, NIH, Bethesda, MD, USA; 3University La Sapienza, Rome, Italy
MRI is a phase sensitive detection system and both magnitude and phase time-series are obtained in an fMRI study. In a previous work it was shown that physiologic noise has a greater impact on phase than magnitude images. It was suggested that large scale fluctuations of the static magnetic field due to respiration and heart beat are the main cause of this difference. In this work we first characterised the effect of physiologic parameters (ECG and respiration) on the magnitude and the phase signal and then investigated the effect of different post-processing methods, including spatial filtering.