title: Reproducibility of multiphase pseudo-continuous arterial spin labeling and the effect of post-processing analysis methods.
abstract: Arterial spin labeling (ASL) is an emerging MRI technique for non-invasive measurement of cerebral blood flow (CBF). Compared to invasive perfusion imaging modalities, ASL suffers from low sensitivity due to poor signal-to-noise ratio (SNR), susceptibility to motion artifacts and low spatial resolution, all of which limit its reliability. In this work, the effects of various state of the art image processing techniques for addressing these ASL limitations are investigated. A processing pipeline consisting of motion correction, ASL motion correction imprecision removal, temporal and spatial filtering, partial volume effect correction, and CBF quantification was developed and assessed. To further improve the SNR for pseudo-continuous ASL (PCASL) by accounting for errors in tagging efficiency, the data from multiphase (MP) acquisitions were analyzed using a novel weighted-averaging scheme. The performances of each step in terms of SNR and reproducibility were evaluated using test-retest ASL data acquired from 12 young healthy subjects. The proposed processing pipeline was shown to improve the within-subject coefficient of variation and regional reproducibility by 17% and 16%, respectively, compared to CBF maps computed following motion correction but without the other processing steps. The CBF measurements of MP-PCASL compared to PCASL had on average 23% and 10% higher SNR and reproducibility, respectively.
authors.affiliation: CSIRO Digital Productivity Flagship, The Australian e-Health Research Centre, Herston, QLD, Australia; Le2I, University of Burgundy, Le Creusot, France. Electronic address: fazlollahi@gmail.com.
authors.forename: Amir
authors.initials: A
authors.lastname: Fazlollahi
authors.affiliation: CSIRO Digital Productivity Flagship, The Australian e-Health Research Centre, Herston, QLD, Australia.
authors.forename: Pierrick
authors.initials: P
authors.lastname: Bourgeat
authors.affiliation: Florey Institute of Neuroscience and Mental Health, Heidelberg, Victoria, Australia.
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Liang
authors.affiliation: Le2I, University of Burgundy, Le Creusot, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Meriaudeau
authors.affiliation: Florey Institute of Neuroscience and Mental Health, Heidelberg, Victoria, Australia; Department of Medicine, Austin Health and Northern Health, University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Alan
authors.initials: A
authors.lastname: Connelly
authors.affiliation: CSIRO Digital Productivity Flagship, The Australian e-Health Research Centre, Herston, QLD, Australia.
authors.forename: Olivier
authors.initials: O
authors.lastname: Salvado
authors.affiliation: Florey Institute of Neuroscience and Mental Health, Heidelberg, Victoria, Australia; Department of Medicine, Austin Health and Northern Health, University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Fernando
authors.initials: F
authors.lastname: Calamante
mesh_terms: D000328:Adult; D016477:Artifacts; D001921:Brain / Q000098:blood supply*; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio; D013113:Spin Labels; D055815:Young Adult
chemical_list: D013113:Spin Labels
keywords: Arterial spin labeling; Cerebral blood flow; Multiphase pseudo-continuous arterial spin labeling; Perfusion MRI; Reproducibility; Test–retest