title: Multi-centre reproducibility of diffusion MRI parameters for clinical sequences in the brain.
abstract: The purpose of this work was to assess the reproducibility of diffusion imaging, and in particular the apparent diffusion coefficient (ADC), intra-voxel incoherent motion (IVIM) parameters and diffusion tensor imaging (DTI) parameters, across multiple centres using clinically available protocols with limited harmonization between sequences. An ice-water phantom and nine healthy volunteers were scanned across fives centres on eight scanners (four Siemens 1.5T, four Philips 3T). The mean ADC, IVIM parameters (diffusion coefficient D and perfusion fraction f) and DTI parameters (mean diffusivity MD and fractional anisotropy FA), were measured in grey matter, white matter and specific brain sub-regions. A mixed effect model was used to measure the intra- and inter-scanner coefficient of variation (CV) for each of the five parameters. ADC, D, MD and FA had a good intra- and inter-scanner reproducibility in both grey and white matter, with a CV ranging between 1% and 7.4%; mean 2.6%. Other brain regions also showed high levels of reproducibility except for small structures such as the choroid plexus. The IVIM parameter f had a higher intra-scanner CV of 8.4% and inter-scanner CV of 24.8%. No major difference in the inter-scanner CV for ADC, D, MD and FA was observed when analysing the 1.5T and 3T scanners separately. ADC, D, MD and FA all showed good intra-scanner reproducibility, with the inter-scanner reproducibility being comparable or faring slightly worse, suggesting that using data from multiple scanners does not have an adverse effect compared with using data from the same scanner. The IVIM parameter f had a poorer inter-scanner CV when scanners of different field strengths were combined, and the parameter was also affected by the scan acquisition resolution. This study shows that the majority of diffusion MRI derived parameters are robust across 1.5T and 3T scanners and suitable for use in multi-centre clinical studies and trials.
authors: Developmental Imaging and Biophysics Section, UCL Institute of Child Health, University College London, London, UK.
authors: Matthew
authors: M
authors: Grech-Sollars
authors: Patrick W
authors: PW
authors: Hales
authors: Keiko
authors: K
authors: Miyazaki
authors: Felix
authors: F
authors: Raschke
authors: Daniel
authors: D
authors: Rodriguez
authors: Martin
authors: M
authors: Wilson
authors: Simrandip K
authors: SK
authors: Gill
authors: Tina
authors: T
authors: Banks
authors: Dawn E
authors: DE
authors: Saunders
authors: Jonathan D
authors: JD
authors: Clayden
authors: Matt N
authors: MN
authors: Gwilliam
authors: Thomas R
authors: TR
authors: Barrick
authors: Paul S
authors: PS
authors: Morgan
authors: Nigel P
authors: NP
authors: Davies
authors: James
authors: J
authors: Rossiter
authors: Dorothee P
authors: DP
authors: Auer
authors: Richard
authors: R
authors: Grundy
authors: Martin O
authors: MO
authors: Leach
authors: Franklyn A
authors: FA
authors: Howe
authors: Andrew C
authors: AC
authors: Peet
authors: Chris A
authors: CA
authors: Clark
mesh_terms: D000328:Adult; D016880:Anisotropy; D001834:Body Water; D001921:Brain / Q000033:anatomy & histology*; D004058:Diffusion; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D056324:Diffusion Tensor Imaging / Q000379:methods; D006801:Humans; D007053:Ice; D008962:Models, Theoretical; D009038:Motion; D059906:Neuroimaging / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D014867:Water; D066127:White Matter / Q000033:anatomy & histology
chemical_list: D007053:Ice; D014867:Water
keywords: MRI; brain; diffusion; multi-centre; reproducibility