About this task
To change ASL settings, make a selection from the desired ASL screens.Step-by-step instructions
- From the ASL screen, click and drag the left threshold slider until the brain is outlined in green and all the anatomy inside the image displays green lines. This indicates that all the anatomy inside the brain is used for the map calculations and the noise outside the brain is not used.
Note: Compute does not update the threshold. As the upper or lower slider is moved or a value entered in the text box, the threshold automatically updates.
- For processing threshold details, see the threshold adjustment procedure.
- From the ASL screen title bar, click the Tools icon (
). - From the ASL screen, click the ASL - Advanced Settings arrow to change the default parameters or Kernel Spatial Smoothing.
- As the kernel size increases, voxel averaging occurs and the image maps appear smoother.
- Labeling Efficiency is a factor that accounts for incomplete inversion during tagging. It is the fraction of the maximum possible change in the longitudinal magnetization, which has been measured to be 80%.
- Partition Coefficient is the equilibrium of tissue/blood partition coefficient of water. The default value is 0.9ml/g.
- Change the desired settings.
- Click Compute to generate updated maps.
- Reset changes the selections to the factory default values.
- Save All saves your selections as the new default values.
- From the ASL screen, click the ASL - Final Settings arrow to review the settings. If you want to change any of the settings, click the appropriate selection from the ASL screen. Click Compute to generate updated maps.
- Optional: To compare ROI statistics from two locations on either side of an axis of symmetry, from the Review steps, click Mirror ROI and follow the steps in Mirror ROI.
- To exit READY View, click the Exit icon (
).
