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Denoise functional magnetic resonance imaging with variance-stabilizing transformation and optimal singular value shrinkage (VST-SVS)
Wei Zhu1, Xiaodong Ma1, Xiao-Hong Zhu1, Kamil Uğurbil1, Wei Chen1, and Xiaoping Wu1
1University of Minnesota, Minneapolis, MN, United States
Our method when used to denoise single-run fMRI data enhances the performance for estimation of BOLD activations to a level comparable to what is achievable with averaged 20 runs but using conventional Gaussian smoothing.
Fig. 4 In-vivo experiment: comparing denoising performances for VST-SVS vs Gaussian smoothing (Gauss) vs MPPCA in terms of BOLD percent change. Note that the proposed VST-SVS method outperformed the conventional Gaussian smoothing when both used to denoise a single run, increasing activation areas to a level visually comparable in size to what was achievable with Gaussian smoothing but using all 20 runs.
Fig. 5 In-vivo experiment: laminar BOLD profiles are shown for both hemispheres and are displayed for noisy data (black lines), Gaussian smoothing (red lines), and VST-SVS (α=0, patch averaging) (blue lines) derived from either single run (ind, solid lines) or concatenated 20 runs (mul, dashed lines). Note that the use of VST-SVS to denoise a single run gave rise to a laminar profile comparable to that achievable with 20 runs using conventional Gaussian smoothing.