Research Article Tract-Based Spatial Statistics: Application to Mild Cognitive Impairment Yau-Yau Wai, 1,2 Wen-Chuin Hsu, 3,4 Hon-Chung Fung, 3 Jiann-Der Lee, 5 Hsiao-Lung Chan, 5 Ming-Lun Tsai, 2 Yu-Chun Lin, 1,2 Yih-Ru Wu, 3 Leslie Ying, 6,7 and Jiun-Jie Wang 1,2,8,9,10 1 Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan County, Taiwan 2 Department of Radiology and Intervention, Chang Gung Memorial Hospital, 5 FuHsing Street, Linkou, Taoyuan County, Taiwan 3 Department of Neurology, Chang Gung Memorial Hospital, Chang-Gung University College of Medicine, Linkou, New Taipei 333, Taiwan 4 Dementia Center, Chang Gung Memorial Hospital, 5 FuHsing Street, Linkou, Taoyuan County, Taiwan 5 Department of Electrical Engineering, Chang Gung University, 259 WenHua 1st Road, Taoyuan County, Taoyuan, Taiwan 6 Department of Biomedical Engineering, University at Bufalo, he State University of New York, Bufalo, NY 14260, USA 7 Department of Electrical Engineering, University at Bufalo, he State University of New York, Bufalo, NY 14260, USA 8 Neuroscience Research Center, Chang Gung Memorial Hospital, 5 FuHsing Street, Linkou, Taoyuan County, Taiwan 9 Institute of Radiological Research, Chang Gung University, Chang Gung Memorial Hospital, 5 FuHsing Street, Linkou, Taoyuan County, Taiwan 10 Healthy Aging Research Center, Chang Gung University, 259 WenHua 1st Road, Taoyuan County, Taoyuan, Taiwan Correspondence should be addressed to Jiun-Jie Wang; jwang@mail.cgu.edu.tw Received 10 January 2014; Accepted 10 April 2014; Published 12 May 2014 Academic Editor: Hengyi Rao Copyright © 2014 Yau-Yau Wai et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Rationale and Objectives. he primary objective of the current investigation was to characterize white matter integrity in diferent subtypes of mild cognitive impairment (MCI) using tract-based spatial statistics of difusion tensor imaging. Materials and Methods. he study participants were divided into 4 groups of 30 subjects each as follows: cognitively healthy controls, amnestic MCI, dysexecutive MCI, and Alzheimer’s disease (AD). All subjects underwent a comprehensive neuropsychological assessment, apolipoprotein E genotyping, and 3-tesla MRI. he difusion tensor was reconstructed and then analyzed using tract-based spatial statistics. he changes in brain white matter tracts were also examined according to the apolipoprotein E 4 status. Results. Compared with controls, amnestic MCI patients showed signiicant diferences in the cerebral white matter, where changes were consistently detectable in the frontal and parietal lobes. We found a moderate impact of the apolipoprotein E 4 status on the extent of white matter disruption in the amnestic MCI group. Patients with AD exhibited similar but more extensive alterations, while no signiicant changes were observed in dysexecutive MCI patients. Conclusion. he results from this study indicate that amnestic MCI is the most likely precursor to AD as both conditions share signiicant white matter damage. By contrast, dysexecutive MCI seems to be characterized by a distinct pathogenesis. 1. Introduction Dementia refers to a clinical syndrome of acquired intellec- tual disturbances produced by brain dysfunction [1]. Mild cognitive impairment (MCI) is considered to be the clinical transition stage between normal aging and dementia [2]. Evidence suggests that subjects with MCI tend to progress to probable Alzheimer’s disease (AD) at a rate of approximately 10% to 15% per year [2]. However, MCI is a clinically het- erogeneous syndrome, with some patients showing isolated memory impairments (i.e., amnestic MCI) and others with isolated executive function impairments (i.e., dysexecutive Hindawi Publishing Corporation BioMed Research International Volume 2014, Article ID 713079, 8 pages http://dx.doi.org/10.1155/2014/713079