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P4‐095: CONTOURLET‐BASED FEATURE EXTRACTION FOR COMPUTER‐AIDED CLASSIFICATION OF ALZHEIMER'S DISEASE
Author(s) -
Jha Debesh,
Kwon Goo-Rak
Publication year - 2018
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2018.06.2498
Subject(s) - contourlet , artificial intelligence , discriminative model , pattern recognition (psychology) , classifier (uml) , feature extraction , computer science , feature selection , support vector machine , cross validation , disease , principal component analysis , medicine , pathology , wavelet transform , wavelet
to global PiB uptake ratio may indicate the presence of CAA. Methods:The ratio of occipital to global PiB uptake was calculated for 140 carriers of a mutation associated with ADAD who had positive PiB scans (mean cortical FSUVR > 1.42). We categorized individuals into groups based on the presence or absence of microhemorrhages (MCH) on MRI, and further divided the group without MCH into those with or without a mutation with documented neuropathological evidence of consistent and severe CAA in the literature. Groups were subdivided into asymptomatic, mild cognitive impairment (MCI), or dementia based on their score on the Clinical Dementia Rating Scale, as well as APOE e4 carriers vs. non-carriers. T-tests were used to compare groups for continuous variables and chi-squared tests for categorical variables. Results: Occipital/global PiB uptake was significantly higher for individuals with MCH than those without for the dementia group (mean ratio 1.01 vs 0.73, p1⁄40.046), but not the MCI group (0.84 vs 0.75, p1⁄40.36) or asymptomatic group (0.86 vs 0.94, p1⁄40.49). For individuals without MCH, occipital/global PiB uptake was significantly higher for individuals with CAA-associated mutations than in mutations not associated with CAA in the dementia group (0.78 vs 0.51, p1⁄40.008) but not in the MCI group (0.77 vs 0.61, p1⁄40.16) or asymptomatic group (0.90 vs 0.81, p1⁄40.37). There was no significant difference between prevalence of APOE e4 carriers between individuals with and without MCH (p1⁄40.77) and with or without CAA-associated mutations (p1⁄40.34). Conclusions: Occipital/ global PiB uptake is associated with the presence of microhemorrhages and with specific mutations known to be associated with CAA in the DIAN for individuals who already have dementia but not in those who are asymptomatic or at the MCI stage. Our findings suggest that increased occipital uptake of PiB is a later finding in CAA in ADAD.