SetUp M0 Image


- clone ASL sequence

- disable labeling

- disable background suppression

- set TR=2 seconds (this removes contrast between tissue types)

- choose between n=1 and n=5 repetitions (1 should be sufficient, but you can do 5 to be more safe)


- motion correction (if multiple repetitions)

- smooth to avoid SNR loss by (co-la)/M0 division (careful not to smooth low extracranial and high CSF values into GM/WM, best to mask them out first)

- correct T1 recovery: M0 ./ (1-exp(-NetTR/x.Q.T1tissue)) where x.Q.T1tissue = 1240 ms by default (with 2D NetTR is a range)

Advantages compared to the most quantitatively correct M0:

- consistent with white paper

- fool proof acquisition/easy

- cancels out coil inhomogeneity


- tissue-weighted rather than blood M0 weighted

- division can loose SNR

- smoothing can introduce very low extracranial and very high CSF values