title: Identification of progressive mild cognitive impairment patients using incomplete longitudinal MRI scans.
abstract: Distinguishing progressive mild cognitive impairment (pMCI) from stable mild cognitive impairment (sMCI) is critical for identification of patients who are at risk for Alzheimer's disease (AD), so that early treatment can be administered. In this paper, we propose a pMCI/sMCI classification framework that harnesses information available in longitudinal magnetic resonance imaging (MRI) data, which could be incomplete, to improve diagnostic accuracy. Volumetric features were first extracted from the baseline MRI scan and subsequent scans acquired after 6, 12, and 18 months. Dynamic features were then obtained using the 18th month scan as the reference and computing the ratios of feature differences for the earlier scans. Features that are linearly or non-linearly correlated with diagnostic labels are then selected using two elastic net sparse learning algorithms. Missing feature values due to the incomplete longitudinal data are imputed using a low-rank matrix completion method. Finally, based on the completed feature matrix, we build a multi-kernel support vector machine (mkSVM) to predict the diagnostic label of samples with unknown diagnostic statuses. Our evaluation indicates that a diagnosis accuracy as high as 78.2 % can be achieved when information from the longitudinal scans is used-6.6 % higher than the case using only the reference time point image. In other words, information provided by the longitudinal history of the disease improves diagnosis accuracy.
authors.affiliation: Department of Radiology and BRIC, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: Kim-Han
authors.identifier: 0000-0003-1379-2185
authors.initials: KH
authors.lastname: Thung
authors.affiliation: Department of Radiology and BRIC, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.|Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore, Singapore.
authors.forename: Chong-Yaw
authors.initials: CY
authors.lastname: Wee
authors.affiliation: Department of Radiology and BRIC, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: Pew-Thian
authors.initials: PT
authors.lastname: Yap
authors.affiliation: Department of Radiology and BRIC, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. dgshen@med.unc.edu.|Department of Brain and Cognitive Engineering, Korea University, Seoul, Korea. dgshen@med.unc.edu.
authors.forename: Dinggang
authors.initials: D
authors.lastname: Shen
mesh_terms: D000368:Aged; D000465:Algorithms; D001921:Brain / Q000473:pathology*; D060825:Cognitive Dysfunction / Q000145:classification / Q000175:diagnosis* / Q000473:pathology*; D003627:Data Interpretation, Statistical; D016208:Databases, Factual; D018450:Disease Progression; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D012680:Sensitivity and Specificity; D060388:Support Vector Machine
keywords: Elastic net; Longitudinal MRI; Low-rank matrix completion; Missing data; Multi-kernel learning; Progressive mild cognitive impairment (pMCI)