Yoko,
I have struggled myslef with this issue last year when a colleague brought me pCASL data acquired using some 3T scanner similar to ours, but at different location.
The short story is that perfusion packages are not standardized yet and analysis methods for ASL data require full knolwedge of your acquistion parameters and preparation.
All depdn on signal subtraction and then a scalar/refrence to set the absolute units of perfusion, otherwise there is no way of getting accurate values.
My review of ~ 20 years of published literaure on the human brain regional perfusion indciates inconsistent reports if you try to see universal age and gender trends, at least compared to
MRI phase sensitive methods () and NO2inhalation-CT-SPECT-SPECT reports on age trends which date as early as 1956 (Kety 1956 --classic review), but this does NOT mean the MRI method can not be used.
(see the work below Hasan et al. 2013; as it has some healthy brain data and quality assurance measures I found useful while addressing Reviewer feedback.
The package you cited has useful steps, but also customize it to your data acquistion details.
In short, be careful as the CBF-ASL method requires calibration, assumes blood-related constants that can be variable in some pathologies and may differ betwee males and females or age.
Hasan KM, Ali H, Shad MU. Atlas-based and DTI-guided quantification of human brain cerebral blood flow: feasibility, quality assurance,
spatial heterogeneity and age effects. Magn Reson Imaging. 2013;31:1445-52 (see references therein)
Kety SS. Human cerebral blood flow and oxygen consumption as related to aging. J Chronic Dis 1956;3:478-486.
Khader M Hasan, PhD
Associate Professor of Radiology
MSE 168, Tel 713 500 7690 (FAX 713 500 7684)
University of Texas Health Science Center at Houston
Medical School
Diagnostic and Interventional Imaging
Magnetic Resonance Imaging Research Division
Diffusion Tensor Imaging Lab, Tel 713 500 7683
http://www.uth.tmc.edu/radiology/faculty/khader-m-hasan/index.html<http://www.uth.tmc.edu/radiology/faculty/hasan.html>
________________________________
From: SPM (Statistical Parametric Mapping) [[log in to unmask]] On Behalf Of Yuko [[log in to unmask]]
Sent: Friday, March 21, 2014 11:21 AM
To: [log in to unmask]
Subject: [SPM] ASL analysis
Dear Experts,
I have functional ASL data and proton density reference images.
I would like to analyze this data.
I tried to use SPM toolbox, ASL_toolbox. But it didn't work in my PC.
I wonder if someone could suggest me to use some other softwares, or some points to use ASL toolbox.
Any suggestion or advice will be highly appreciated.
Many thanks,
Yuko
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