title: Validation of an MRI Rating Scale for Amyloid-Related Imaging Abnormalities.
abstract: Immunotherapeutic agents against amyloid beta (Aβ) are associated with adverse events, including amyloid-related imaging abnormalities with edema and effusion (ARIA-E). Recently, a magnetic resonance imaging (MRI) rating scale was developed for ARIA-E detection and classification. The aim of this study was to validate the use of this rating scale in a larger patient group with multiple raters.
  
  
  
  MRI scans of 75 patients (29 with known ARIA-E and 46 control subjects) were analyzed by five neuroradiologists with different degrees of expertise, according to the ARIA-E rating scale. For each patient, we included a baseline and a follow-up fluid-attenuated inversion recovery image. Interrater agreement was calculated using intraclass correlation coefficient (ICC).
  
  
  
  On average, 4.1% of the ARIA-E cases were missed. We observed a high interrater agreement for scores of sulcal hyperintensity (SH; ICC = .915; 95% CI 85-95) and for the combined scores of the 2 ARIA-E findings, parenchymal hyperintensity (PH) and SH (ICC = .878; 95% CI 79-93). A slightly lower agreement for PH (ICC = .678; 95% CI 51-81) was noted.
  
  
  
  The ARIA-E rating scale is a simple tool to evaluate the extent of ARIA-E in patients recruited into Aβ-lowering therapeutic trials. It shows high interrater agreement among raters with different degrees of expertise.
authors.affiliation: Image Analysis Centre, Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Arianne
authors.initials: A
authors.lastname: Bechten
authors.affiliation: Image Analysis Centre, Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Mike P
authors.initials: MP
authors.lastname: Wattjes
authors.affiliation: Department of Radiology, California Pacific Medical Center, San Francisco, CA.|BioClinica, Newark, CA.
authors.forename: Derk D
authors.initials: DD
authors.lastname: Purcell
authors.affiliation: Image Analysis Centre, Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Esther Sanchez
authors.initials: ES
authors.lastname: Aliaga
authors.affiliation: Department of Radiology and Nuclear Medicine and Department of Anatomy and Neurosciences, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Marita
authors.initials: M
authors.lastname: Daams
authors.affiliation: Janssen Alzheimer Immunotherapy Research and Development, Fremont, CA.
authors.forename: H Robert
authors.initials: HR
authors.lastname: Brashear
authors.affiliation: Janssen Alzheimer Immunotherapy Research and Development, Fremont, CA.
authors.forename: H Michael
authors.initials: HM
authors.lastname: Arrighi
authors.affiliation: Image Analysis Centre, Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, the Netherlands.|Institutes of Neurology and Healthcare Engineering, UCL, London, UK.
authors.forename: Frederik
authors.initials: F
authors.lastname: Barkhof
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000000981:diagnostic imaging* / Q000188:drug therapy; D016229:Amyloid beta-Peptides; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D058225:Plaque, Amyloid / Q000000981:diagnostic imaging*
chemical_list: D016229:Amyloid beta-Peptides; D061067:Antibodies, Monoclonal, Humanized; D007155:Immunologic Factors
keywords: ARIA (amyloid-related imaging abnormalities); Alzheimer's disease (AD); MRI (magnetic resonance imaging); amyloid beta (Aβ); immunotherapy