title: Quality assurance multicenter comparison of different MR scanners for quantitative diffusion-weighted imaging.
abstract: OBJECTIVE
  To propose a magnetic resonance imaging (MRI) quality assurance procedure that can be used for multicenter comparison of different MR scanners for quantitative diffusion-weighted imaging (DWI).
  
  
  METHODS
  Twenty-six centers (35 MR scanners with field strengths: 1T, 1.5T, and 3T) were enrolled in the study. Two different DWI acquisition series (b-value ranges 0-1000 and 0-3000 s/mm(2) , respectively) were performed for each MR scanner. All DWI acquisitions were performed by using a cylindrical doped water phantom. Mean apparent diffusion coefficient (ADC) values as well as ADC values along each of the three main orthogonal directions of the diffusion gradients (x, y, and z) were calculated. Short-term repeatability of ADC measurement was evaluated for 26 MR scanners.
  
  
  RESULTS
  A good agreement was found between the nominal and measured mean ADC over all the centers. More than 80% of mean ADC measurements were within 5% from the nominal value, and the highest deviation and overall standard deviation were 9.3% and 3.5%, respectively. Short-term repeatability of ADC measurement was found <2.5% for all MR scanners.
  
  
  CONCLUSIONS
  A specific and widely accepted protocol for quality controls in DWI is still lacking. The DWI quality assurance protocol proposed in this study can be applied in order to assess the reliability of DWI-derived indices before tackling single- as well as multicenter studies.
authors.affiliation: Health Physics Unit, USL 8, Arezzo, Italy.
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authors.affiliation: Health Physics Unit, AOU Careggi, Florence, Italy.
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authors.lastname: Busoni
authors.affiliation: AOU Meyer, Florence, Italy.
authors.forename: Antonio
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authors.lastname: Ciccarone
authors.affiliation: Medical Physics Department, Fondazione Fatebenefratelli per la Ricerca e la Formazione sanitaria e sociale, San Giovanni Calibita Hospital, Rome, Italy.
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authors.lastname: Coniglio
authors.affiliation: Health Physics Unit, ASF, Florence, Italy.
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authors.lastname: Esposito
authors.affiliation: Health Physics Unit, AOU Pisana, Pisa, Italy.
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authors.lastname: Giannelli
authors.affiliation: Health Physics Unit, AOU Senese, Siena, Italy.
authors.forename: Lorenzo N
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authors.lastname: Mazzoni
authors.affiliation: Medical Phisics Department, AOU Policlinico Modena, Italy.
authors.forename: Luca
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authors.affiliation: Medical Physics Unit, Arcispedale Santa Maria Nuova - IRCCS, Reggio Emilia, Italy.
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authors.lastname: Sghedoni
authors.affiliation: Health Physics Unit, AOU Perugia, Italy.
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authors.lastname: Tarducci
authors.affiliation: Health Physics Unit, ASF, Florence, Italy.
authors.forename: Giovanna
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authors.affiliation: A.O."Pugliese-Ciaccio," Catanzaro, Italy.
authors.forename: Rosa A
authors.initials: RA
authors.lastname: Anoja
authors.affiliation: Health Physics Unit, AOU Senese, Siena, Italy.
authors.forename: Gina
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authors.lastname: Belmonte
authors.affiliation: UO Direzione Sanitaria, IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
authors.forename: Nicola
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authors.lastname: Bertolino
authors.affiliation: Health Physics Unit, Centro Oncologico Fiorentino, Sesto Fiorentino, Italy.
authors.forename: Margherita
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authors.lastname: Betti
authors.affiliation: Radiodiagnostic Unit, Centro Oncologico Fiorentino, Sesto Fiorentino, Italy.
authors.forename: Cristiano
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authors.lastname: Biagini
authors.affiliation: Medical Phisics Department, AOU Policlinico Modena, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Ciarmatori
authors.affiliation: Azienda Ospedaliera Papa Giovanni XXIII, Bergamo, Italy.
authors.forename: Fabiola
authors.initials: F
authors.lastname: Cretti
authors.affiliation: Health Physics Unit, Ospedale Sant'Orsola-Malpighi, Bologna, Italy.
authors.forename: Emma
authors.initials: E
authors.lastname: Fabbri
authors.affiliation: Health Physics Unit, AOU Careggi, Florence, Italy.
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authors.lastname: Fedeli
authors.affiliation: Health Physics Unit, AOU Parma, Italy.
authors.forename: Silvano
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authors.affiliation: Health Physics Unit, AOU Perugia, Italy.
authors.forename: Christian P L
authors.initials: CP
authors.lastname: Fulcheri
authors.affiliation: Health Physics Unit, USL 8, Arezzo, Italy.
authors.forename: Chiara
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authors.lastname: Gasperi
authors.affiliation: Health Physics Unit, IRCCS-San Raffaele, Milan, Italy.
authors.forename: Paola A
authors.initials: PA
authors.lastname: Mangili
authors.affiliation: Health Physics Unit, ASF, Florence, Italy.
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authors.lastname: Mazzocchi
authors.affiliation: Health Physics Unit, AOU Verona, Italy.
authors.forename: Gabriele
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authors.lastname: Meliadò
authors.affiliation: Health Physics Unit, AO San Gerardo, Monza, Italy.
authors.forename: Sabrina
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authors.lastname: Morzenti
authors.affiliation: Health Physics Unit, AOU Careggi, Florence, Italy.
authors.forename: Linhsia
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authors.lastname: Noferini
authors.affiliation: Health Physics Unit, Azienda Sanitaria dell'Alto Adige-Ospedale Bolzano, Italy.
authors.forename: Nadia
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authors.lastname: Oberhofer
authors.affiliation: Medical Physics Unit, Arcispedale Santa Maria Nuova - IRCCS, Reggio Emilia, Italy.
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authors.lastname: Orsingher
authors.affiliation: Health Physics Unit, AO San Gerardo, Monza, Italy.
authors.forename: Nicoletta
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authors.lastname: Paruccini
authors.affiliation: FISMECO SRL, Rome, Italy.
authors.forename: Goffredo
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authors.lastname: Princigalli
authors.affiliation: Health Physics Unit, ASL 2-Ospedale Campo di Marte, Lucca, Italy.
authors.forename: Mariagrazia
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authors.lastname: Quattrocchi
authors.affiliation: Medical Physics Department, Fondazione Fatebenefratelli per la Ricerca e la Formazione sanitaria e sociale, San Giovanni Calibita Hospital, Rome, Italy.
authors.forename: Adele
authors.initials: A
authors.lastname: Rinaldi
authors.affiliation: Department of Developmental Neuroscience, Stella Maris Scientific Institute, Pisa, Italy.
authors.forename: Danilo
authors.initials: D
authors.lastname: Scelfo
authors.affiliation: CNAO, Pavia, Italy.
authors.forename: Gloria Vilches
authors.initials: GV
authors.lastname: Freixas
authors.affiliation: Magnetic Resonance Center (CERM), University of Florence, Sesto Fiorentino, Italy; FiorGen Foundation, Sesto Fiorentino, Italy.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Tenori
authors.affiliation: UO Direzione Scientifica, IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
authors.forename: Ileana
authors.initials: I
authors.lastname: Zucca
authors.affiliation: Magnetic Resonance Center (CERM), University of Florence, Sesto Fiorentino, Italy; FiorGen Foundation, Sesto Fiorentino, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Luchinat
authors.affiliation: Health Physics Unit, AOU Careggi, Florence, Italy.
authors.forename: Cesare
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authors.lastname: Gori
authors.affiliation: Health Physics Unit, AOU Perugia, Italy.
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mesh_terms: D038524:Diffusion Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods / Q000592:standards*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation* / Q000379:methods / Q000592:standards*; D007558:Italy; D019047:Phantoms, Imaging; D011785:Quality Assurance, Health Care / Q000379:methods / Q000592:standards*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: apparent diffusion coefficient; diffusion weighted imaging; magnetic resonance imaging; quality controls