Bing Wang, Kun Lu, Xiao Zheng, Benyue Su, Yuming Zhou, Peng Chen* and Jun Zhang* Pages 529 - 535 ( 7 )
Background: Alzheimer's disease (AD) has attracted more and more attention in recent years. Accurate diagnosis of AD is significant, especially its prodromal stage, i.e., mild cognitive impairment (MCI), for timely therapy is possibly beneficial to delay the disease progression. Some existing studies indicated that different biomarkers provide complementary information to discriminate MCI patients from healthy normal controls (NCs), but the high complexity of these algorithms brought high computational cost.
Objective: To identify Alzheimer's disease in its early stage with a low computational complexity where the complementary of different biomarkers can still be used.
Method: In this work, we employ the methodology of ensemble learning to construct a two-stage classifier for combining the classification capacity of three biomarkers, i.e., magnetic resonance imaging (MRI), positron emission tomography (PET), and quantification of specific proteins measured through cerebrospinal fluid (CSF), to identify MCIs from healthy controls based on support vector machines algorithm. In the first stage, two SVM classifiers based on MRI and CSF are used for the identification of MCI, respectively. For the samples which can get the same results in the first stage will be seen as the training data, and the ones with the inconsistent result will be put into the second stage as the test data, where PET features are adapted to the classification.
Results: An original dataset downloaded from ADNI database, where 99 MCI patients and 52 healthy controls included, had been adopted for the validation of our proposed method. The experimental results demonstrated the effectiveness of the two-stage ensemble classifier with a classification accuracy of 75.5%, a sensitivity of 78.4% and a specificity of 70.0%.
Conclusion: This study proposed a computational framework to identify the early stage of AD by a two-stage ensemble strategy. The performance of this work shows that combination of different biomarkers can improve identification of MCI with a relatively low computational cost, which is very meaningful for the diagnosis and delay of the AD progress.
Alzheimer`s disease, biomarker, ensemble classifier, mild cognitive impairment, MRI, PET, CSF.
School of Electronical and Information Engineering, Anhui University of Technology, Maanshan, Anhui 243002, School of Electronical and Information Engineering, Anhui University of Technology, Maanshan, Anhui 243002, School of Computer Sciences and Technology, Anhui University of Technology, Maanshan, Anhui 243002, School of Computer Sciences and Information, Anqing Normal University, Anqing, Anhui 246133, School of Electronical and Information Engineering, Anhui University of Technology, Maanshan, Anhui 243002, Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601