title: Brain Parenchymal Fraction in Healthy Adults-A Systematic Review of the Literature.
abstract: Brain atrophy is an important feature of many neurodegenerative disorders. It can be described in terms of change in the brain parenchymal fraction (BPF). In order to interpret the BPF in disease, knowledge on the BPF in healthy individuals is required. The aim of this study was to establish a normal range of values for the BPF of healthy individuals via a systematic review of the literature. The databases PubMed and Scopus were searched and 95 articles, including a total of 9269 individuals, were identified including the required data. We present values of BPF from healthy individuals stratified by age and post-processing method. The mean BPF correlated with mean age and there were significant differences in age-adjusted mean BPF between methods. This study contributes to increased knowledge about BPF in healthy individuals, which may assist in the interpretation of BPF in the setting of disease. We highlight the differences between post-processing methods and the need for a consensus gold standard.
authors.affiliation: Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden.
authors.forename: Mattias
authors.identifier: http://orcid.org/0000-0001-5125-7787
authors.initials: M
authors.lastname: Vågberg
authors.affiliation: Epidemiology and Global Health Unit, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Granåsen
authors.affiliation: Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden.|Department of Clinical Sciences, Karolinska Institutet, Danderyd Hospital, Stockholm, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Svenningsson
mesh_terms: D000328:Adult; D001921:Brain / Q000033:anatomy & histology*; D001927:Brain Diseases / Q000473:pathology*; D006801:Humans; D000072356:Parenchymal Tissue / Q000033:anatomy & histology*