Arno Solin1,
Simo Srkk1, Aapo Nummenmaa2, Aki Vehtari1,
Toni Auranen3, Simo Vanni3, 4, Fa-Hsuan Lin1,
5
1Department
of Biomedical Engineering and Computational Science, Aalto University, Espoo,
Finland; 2Athinoula A. Martinos Center for Biomedical Imaging,
Massachusetts General Hospital, Boston, MA, United States; 3Advanced
Magnetic Imaging Centre, Aalto University, Espoo, Finland; 4Brain
Research Unit, O.V. Lounasmaa Laboratory, Aalto University, Espoo, Finland; 5Institute
of Biomedical Engineering, National Taiwan University, Taipei, Taiwan
In this work we form volumetric temporal phase and amplitude maps of physiological oscillatory signals using fMRI data. We study the spatio-temporal structure of respiration and heart beat induced noises in the brain. The separation of the fMRI data into components was done with a Kalman filter and smoother (the DRIFTER method) using physiological reference signals for identifying the frequencies. We present proof-of-concept maps for one test subject, and discuss how this prior information can be applied to removal or estimation of quickly varying noise components in slow fMRI, and utilized in future fast-imaging techniques.