Mario Zeller1,
Andreas J. Bartsch2, 3, Alexander Mller1,
Marcel Gutberlet4, Dietbert Hahn1, Herbert Kstler1
1Institute
of Radiology, University of Wrzburg, Wrzburg, Germany; 2Department
of Neuroradiology, University of Heidelberg, Heidelberg, Germany; 3FMRIB
Centre, Oxford University, Oxford, United Kingdom; 4Institute for
Interventional and Diagnostic Radiology, Hannover Medical School, Hannover,
Germany
Echo planar images of conventional Cartesian fMRI are often spatially smoothed by a Gaussian filter prior to statistical analysis. K-space density weighting, on the other hand, allows to already record the data with a Gaussian shaped point spread function. This is achieved by sampling the k-space with a non-Cartesian trajectory. Such density weighting can, at the same time, be optimized for SNR efficiency by applying a matched filter. In this study, fMRI finger-tapping experiments were recorded with both approaches. Density weighting demonstrates significantly increased sensorimotor activations compared to conventional Cartesian imaging. Potential benefits of density weighted fMRI are discussed.