ASL Output Tab

This tab controls the output that will be produced.


Output data spaces

Standard data item outputs

The following data items are output:

  • perfusion Tissue perfusion
  • arrival Inferred arterial transit time
  • modelfit Model prediction for comparison with the tag-control differenced data

If Fix label duration is not specified:

  • duration Inferred Label duration

If Fix arterial transit time is not specified:

  • arrival Inferred arterial transit time

If Include macro vascular component is specified:

  • aCBV Macrovascular component

If Allow uncertainty in T1 values is specified:

  • mean_T_1 Tissue T1 value
  • mean_T_1b Blood T1 value

If calibration is included, additional calibrated outputs perfusion_calib and aCBV_calib are also generated.

Data spaces

By default the output is produced in native ASL space (i.e. the same space as the input ASL data). These outputs have the suffix _native. In addition (or instead of) output can be produced in structural space, in which case the outputs will have a suffix of _struc.

Additional outputs

Output parameter variance maps

The Bayesian modelling method used is able to output maps of the estimated parameter variance. This gives a measure of how confident the values in the parameter maps are. These outputs have the suffix _var.

Output mask

If selected the mask used to perform the analysis will be output under the name mask_native.

Output calibration data

The calibration data would include the reference mask used in reference region calibration and the voxelwise M0 image in voxelwise calibration. These outputs have the suffix _calib.

Output corrected input data

This option outputs corrected versions of the input data (ASL and calibration) after motion correction, distortion correction, etc. have been performed. These outputs have the suffix _corr.

Output registration data

This option outputs data used as the reference for registration with the suffix _ref.

Output structural segmentation

This option outputs the brain extracted and segmented (partial volume and mask) maps from the structural data. These outputs have the suffix _struc.

Output model fitting data

This option outputs the full output from the model fitting step. These outputs have the suffix _fitting.


Model fitting is a two-stage multi-step process with a number of intermediate output data files. Selecting this option will generate a large number of output data sets!

Summary report

A summary report in HTML format can be generated - if required you need to select this option and choose an output directory: