title: Early detection of Alzheimer's disease using MRI hippocampal texture.
abstract: Cognitive impairment in patients with Alzheimer's disease (AD) is associated with reduction in hippocampal volume in magnetic resonance imaging (MRI). However, it is unknown whether hippocampal texture changes in persons with mild cognitive impairment (MCI) that does not have a change in hippocampal volume. We tested the hypothesis that hippocampal texture has association to early cognitive loss beyond that of volumetric changes. The texture marker was trained and evaluated using T1-weighted MRI scans from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database, and subsequently applied to score independent data sets from the Australian Imaging, Biomarker & Lifestyle Flagship Study of Ageing (AIBL) and the Metropolit 1953 Danish Male Birth Cohort (Metropolit). Hippocampal texture was superior to volume reduction as predictor of MCI-to-AD conversion in ADNI (area under the receiver operating characteristic curve [AUC] 0.74 vs. 0.67; DeLong test, p = 0.005), and provided even better prognostic results in AIBL (AUC 0.83). Hippocampal texture, but not volume, correlated with Addenbrooke's cognitive examination score (Pearson correlation, r = -0.25, p < 0.001) in the Metropolit cohort. The hippocampal texture marker correlated with hippocampal glucose metabolism as indicated by fluorodeoxyglucose-positron emission tomography (Pearson correlation, r = -0.57, p < 0.001). Texture statistics remained significant after adjustment for volume in all cases, and the combination of texture and volume did not improve diagnostic or prognostic AUCs significantly. Our study highlights the presence of hippocampal texture abnormalities in MCI, and the possibility that texture may serve as a prognostic neuroimaging biomarker of early cognitive impairment.
authors.affiliation: The Image Group, Department of Computer Science, University of Copenhagen, Denmark.|Biomediq A/S, Denmark.
authors.forename: Lauge
authors.initials: L
authors.lastname: Sørensen
authors.affiliation: The Image Group, Department of Computer Science, University of Copenhagen, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Igel
authors.affiliation: Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Rigshospitalet, Denmark.|Center for Healthy Aging, University of Copenhagen, Denmark.
authors.forename: Naja
authors.initials: N
authors.lastname: Liv Hansen
authors.affiliation: Center for Healthy Aging, University of Copenhagen, Denmark.|Research Centre for Prevention and Health, Rigshospitalet-Glostrup, Denmark.
authors.forename: Merete
authors.initials: M
authors.lastname: Osler
authors.affiliation: Center for Healthy Aging, University of Copenhagen, Denmark.|Department of Neuroscience and Pharmacology, University of Copenhagen, Denmark.|Department of Clinical Neurophysiology, Rigshospitalet, Denmark.
authors.forename: Martin
authors.initials: M
authors.lastname: Lauritzen
authors.affiliation: Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Rigshospitalet, Denmark.|Center for Healthy Aging, University of Copenhagen, Denmark.
authors.forename: Egill
authors.initials: E
authors.lastname: Rostrup
authors.affiliation: The Image Group, Department of Computer Science, University of Copenhagen, Denmark.|Biomediq A/S, Denmark.
authors.forename: Mads
authors.initials: M
authors.lastname: Nielsen
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D019540:Area Under Curve; D003071:Cognition; D015331:Cohort Studies; D016208:Databases, Factual; D042241:Early Diagnosis; D005260:Female; D005947:Glucose / Q000378:metabolism; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D049268:Positron-Emission Tomography; D011379:Prognosis
chemical_list: D005947:Glucose
keywords: biomarker; classification; early diagnosis; hippocampus; image analysis; machine learning; magnetic resonance imaging; mild cognitive impairment