Arterial Spin Labeling (ASL) FAQs

• How do I acquire baseline whole-brain perfusion maps in humans using ASL on GE 3.0T?
• What protocols are available at the Center for measuring whole-brain perfusion in humans?
• What are the latest updates on the CBF processing software?

• How do I acquire baseline whole-brain perfusion maps in humans using ASL on GE 3.0T?

A detailed instruction manual that covers data acquisition, reconstruction and CBF quantification can be downloaded here

Data reconstruction and CBF quantification software (Matlab-based):

Recent Updates: 

05/13/2009:  All matlab programs were developed in Matlab version 2007a, and may not work in older matlab versions.  

09/19/2008: FSL 4.1.0 no longer supports ANALYZE format, therefore will not work with any of the Center offered software.  Please do NOT upgrade to FSL4.1.0 at this time. Use FSL4.0 or 3.x !

09/12/2008: Tthe software has been updated to be compatible with FSL4.0.  This update is  backward-compatible with FSL3x.

SENSErc1.3_14x.tar - SENSE recon code for the upgraded software platforms 14x (3twest since Jan 2007, 3teast since Nov 2007)
(SENSErc1.3.tar - SENSE reconstruction code for data acquired before the upgrade)

CBFv3.3.tar- CBF quantification (backward compatible with pre-14x software platforms)

If you would like to schedule a training session for baseline whole-brain perfusion using ASL, please contact Kun Lu.

• What protocols are available at the Center for measuring whole-brain perfusion in humans?
  

Protocol name	Brain_perfusion_4S	Brain_perfusion_SS
Description	FAIR ASL Spiral-out readout 4 interleaves gr recon and optional SENSE recon Scan time (6:40min) + calibration scans (1:00min)	FAIR ASL Spiral-out readout Single shot gr recon Scan time (4:10min) + calibration scans (1:00min)
Pros	Reduced drop out in the frontal and medial-temporal lobe regions. Reduced T2* blurring	Shorter scans Fast reconstruction (< 5minutes)
Cons	Longer scans Slow reconstruction  in Matlab (> 4 hrs ) when using the optional SENSE recon program	Increased signal drop out in the frontal/ medial- temporal lobe regions. Increased T2* blurring
Recommended use	Recommended for all studies. The optional SENSE recon is strongly recommended for a more robust performance.	Recommended for motor and visual cortex studies that desire faster scans and data processing.

• What are the latest updates on the CBF processing software?

Software version	Additional functionality
CBFv1.0	Original release
CBFv2.0	Anatomical can be used for CSF voxel identification
CBFv2.1	Fixed small bug in v2.0
CBFv2.2	Performs checks, e.g. that ASL and CSF runs acquired with same prescan. Also handles other tagging schemes aside from PASL
CBFv2.3	Fixed small bug in v2.2
CBFv2.4	ASL and CSF scans acquired with different R1 values can be processed; correction is applied. User is warned to check acquisition protocol
CBFv3.0	(1) Performs motion correction of ASL data. (2) Checks system's software versions. (3) Easier CSF slice selecting when using anatomical. (4) User is asked to check alignment of CSF scan relative to the anatomical (if used)
CBFv3.1	Compatible with data collected on GE 3T and 1.5T scanners
CBFv3.2	Made compatible with FSL4 and fixed small bugs
CBFv3.3	Added Gaussian filter option to smooth the ouput CBF brik for the 4 interleave data if desired.  Default is off.