Xiaoyun Liang1,
Alan Connelly1, 2, Fernando Calamante1,
2
1Brain
Research Institute, Florey Institute of Neuroscience and Mental Health, Heidelberg,
VIC, Australia; 2Department of Medicine, Austin Health and
Northern Health, University of Melbourne, Melbourne, VIC, Australia
The SNR of fMRI images is critical for functional connectivity studies. Although ASL has some advantages over BOLD fMRI, the reliability for detecting networks may be compromised due to its intrinsic low SNR. In this study, we proposed a denoising method combining block-wise non-local means and dual-tree complex wavelet transform to enhance the SNR of ASL images. Simulations show that the proposed method was superior to discrete wavelet transform. The validity of the proposed method has been further confirmed by the more robust detection of functional connectivity from in vivo data. Overall, the proposed method can enhance the SNR of ASL data significantly and thus enable more reliable network detection.