Compressed Sensing MRI
3 requirements for CS application
- Transform Sparsity
- Incoherence of undersampling artifacts
- Nonlinear reconstruction
Sampling must be incoherent, (random ideally). 实际上，sampling trajectory 必须满足hardware和physiological constraints。Non-Cartesian sampling is highly sensitive to system imperfections.
uniform random sampling 不是在k-space上均匀采样，而应该考虑能量分布的uniform。所以应该是中心位置密一些，外围采样稀疏一些。