title: Multi-vendor reliability of arterial spin labeling perfusion MRI using a near-identical sequence: implications for multi-center studies.
abstract: BACKGROUND
  A main obstacle that impedes standardized clinical and research applications of arterial spin labeling (ASL), is the substantial differences between the commercial implementations of ASL from major MRI vendors. In this study, we compare a single identical 2D gradient-echo EPI pseudo-continuous ASL (PCASL) sequence implemented on 3T scanners from three vendors (General Electric Healthcare, Philips Healthcare and Siemens Healthcare) within the same center and with the same subjects.
  
  
  METHODS
  Fourteen healthy volunteers (50% male, age 26.4±4.7years) were scanned twice on each scanner in an interleaved manner within 3h. Because of differences in gradient and coil specifications, two separate studies were performed with slightly different sequence parameters, with one scanner used across both studies for comparison. Reproducibility was evaluated by means of quantitative cerebral blood flow (CBF) agreement and inter-session variation, both on a region-of-interest (ROI) and voxel level. In addition, a qualitative similarity comparison of the CBF maps was performed by three experienced neuro-radiologists.
  
  
  RESULTS
  There were no CBF differences between vendors in study 1 (p>0.1), but there were CBF differences of 2-19% between vendors in study 2 (p<0.001 in most gray matter ROIs) and 10-22% difference in CBF values obtained with the same vendor between studies (p<0.001 in most gray matter ROIs). The inter-vendor inter-session variation was not significantly larger than the intra-vendor variation in all (p>0.1) but one of the ROIs (p<0.001).
  
  
  CONCLUSIONS
  This study demonstrates the possibility to acquire comparable cerebral CBF maps on scanners of different vendors. Small differences in sequence parameters can have a larger effect on the reproducibility of ASL than hardware or software differences between vendors. These results suggest that researchers should strive to employ identical labeling and readout strategies in multi-center ASL studies.
authors.affiliation: Department of Radiology, Academic Medical Center, Amsterdam, The Netherlands. Electronic address: henkjanmutsaerts@gmail.com.
authors.forename: Henri J M M
authors.initials: HJ
authors.lastname: Mutsaerts
authors.affiliation: C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Matthias J P
authors.initials: MJ
authors.lastname: van Osch
authors.affiliation: Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, UK.
authors.forename: Fernando O
authors.initials: FO
authors.lastname: Zelaya
authors.affiliation: Department of Neurology, UCLA, Los Angeles, USA.
authors.forename: Danny J J
authors.initials: DJ
authors.lastname: Wang
authors.affiliation: The Intervention Center, Oslo University Hospital, Oslo, Norway.
authors.forename: Wibeke
authors.initials: W
authors.lastname: Nordhøy
authors.affiliation: Department of Neurology, UCLA, Los Angeles, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, UK.
authors.forename: Stephen
authors.initials: S
authors.lastname: Wastling
authors.affiliation: Division of Neuroscience, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Fernandez-Seara
authors.affiliation: Department of Radiology, University Medical Center, Utrecht, The Netherlands.
authors.forename: E T
authors.initials: ET
authors.lastname: Petersen
authors.affiliation: Division of Neuroradiology, University of Verona, Verona, Italy.
authors.forename: Francesca B
authors.initials: FB
authors.lastname: Pizzini
authors.affiliation: Brain Repair & Rehabilitation, Institute of Neurology, UCL, London, UK.
authors.forename: Sameeha
authors.initials: S
authors.lastname: Fallatah
authors.affiliation: Department of Radiology, University Medical Center, Utrecht, The Netherlands.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Hendrikse
authors.affiliation: The Intervention Center, Oslo University Hospital, Oslo, Norway.
authors.forename: Oliver
authors.initials: O
authors.lastname: Geier
authors.affiliation: Fraunhofer MEVIS, Bremen, Germany; MR Physics, University of Bremen, Bremen, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Günther
authors.affiliation: Brain Repair & Rehabilitation, Institute of Neurology, UCL, London, UK.
authors.forename: Xavier
authors.initials: X
authors.lastname: Golay
authors.affiliation: Department of Radiology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Aart J
authors.initials: AJ
authors.lastname: Nederveen
authors.affiliation: The Intervention Center, Oslo University Hospital, Oslo, Norway; Department of Physics, University of Oslo, Oslo, Norway.
authors.forename: Atle
authors.initials: A
authors.lastname: Bjørnerud
authors.affiliation: Department of Psychology, Institute of Social Sciences, University of Oslo, Oslo, Norway.
authors.forename: Inge R
authors.initials: IR
authors.lastname: Groote
mesh_terms: D000328:Adult; D016477:Artifacts; D002536:Cerebral Arteries / Q000033:anatomy & histology* / Q000502:physiology; D002560:Cerebrovascular Circulation; D017352:Echo-Planar Imaging / Q000295:instrumentation / Q000592:standards; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000592:standards; D008297:Male; D009038:Motion; D015337:Multicenter Studies as Topic; D010477:Perfusion; D012015:Reference Standards; D015203:Reproducibility of Results; D013113:Spin Labels; D055815:Young Adult
chemical_list: D013113:Spin Labels
keywords: Arterial spin labeling; Cerebral blood flow; Inter-vendor; Repeatability; Reproducibility