Chenyang Zhao1, Xingfeng Shao1, Lirong Yan1, and Danny JJ Wang1
1Laboratory of Functional MRI Technology (LOFT), Mark & Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, United States
1Laboratory of Functional MRI Technology (LOFT), Mark & Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, United States
KWIA is a
denoising algorithm for dynamic MRI, which showed promising use in multi-delay
ASL and ASL-based 4D dMRA. Significant SNR improvement enables better
visualization and quantification for both applications.
(a) Schematic
diagram of KWIA with 3 rings. When KWIA is applied to the selected time frame,
5 frames within the KWIA window are weighted averaged and synthesized to a
KWIA-filtered k-space. The weighting function and KWIA-filtered k-space are
given. (b) Predicted theoretical SNR improvement of KWIA with 2, 3, and 4
rings. SNR improvement increases with greater number of rings and smaller ratio
of the first ring to the full radius. (C) Simulated SNR improvements under 7
MRI conditions that are consistent with expected ratios.
Comparison of the
original and KWIA-filtered 15-delay pCASL perfusion images. Two-fold SNR
improvement was achieved by KWIA resulting in better image quality and dynamic
visualization. No obvious degradation of spatial and temporal resolution was
found.
