  The method of Arterial Spin Labeling (ASL) has experienced a significant rise
in its application to functional imaging, since it is the only technique
capable of measuring blood perfusion in a truly non-invasive manner. Currently,
there are no commercial packages for processing ASL data and there is no
recognised standard for normalising ASL data to a common frame of reference.
This work describes a new Automated Software for ASL Processing (ASAP) that can
automatically process several ASL datasets. ASAP includes functions for all
stages of image pre-processing: quantification, skull-stripping,
co-registration, partial volume correction and normalization. To assess the
applicability and validity of the toolbox, this work shows its application in
the study of hypoperfusion in a sample of healthy subjects at risk of
progressing to Alzheimer's Disease. ASAP requires limited user intervention,
minimising the possibility of random and systematic errors, and produces
cerebral blood flow maps that are ready for statistical group analysis. The
software is easy to operate and results in excellent quality of spatial
normalisation. The results found in this evaluation study are consistent with
previous studies that find decreased perfusion
