aslprep.utils.asl module
Functions for working with ASL data.
- estimate_labeling_efficiency(metadata)[source]
Estimate labeling efficiency based on the available metadata.
- Parameters:
metadata (
dict
) – Dictionary of metadata from the ASL file.- Returns:
labeleff – Labeling efficiency.
- Return type:
Notes
If LabelingEfficiency is defined in the metadata, then this value will be used. Otherwise, efficiency will be estimated based on the ASL type and number of background suppression pulses (if any). PCASL and PASL values come from Alsop et al.[1]. The CASL value comes from Wang et al.[2]. The adjustment based on number of background suppression pulses is not described in any papers, as far as we know, but is apparently widely used.
References
- get_bolus_duration(metadata: dict[str, Any], is_casl: bool) float [source]
Determine the appropriate bolus duration for BASIL.
For PASL data, the bolus cutoff delay is the first BolusCutOffDelayTime. For (P)CASL data, it is the labeling duration.
- get_inflow_times(metadata: dict[str, Any], is_casl: bool) list [source]
Determine the appropriate inflow times for BASIL.
For PASL data, the inflow time (TI) is just the post-labeling delay (PLD). For (P)CASL data, TI is PLD plus the labeling duration.
- Parameters:
- Returns:
1D array of PostLabelingDelay values.
- Return type: