Gray & white matter tissue contrast differentiates Mild Cognitive Impairment converters from non-converters.
The clinical relevance of gray/white matter contrast ratio (GWR) in mild cognitive impairment (MCI) remains unknown. This study examined baseline GWR and 3-year follow-up diagnostic status in MCI. Alzheimer's Disease Neuroimaging Initiative MCI participants with baseline 1.5 T MRI and 3-year follow-up clinical data were included. Participants were categorized into two groups based on 3-year follow-up diagnoses: 1) non-converters (n = 69, 75 ± 7, 26 % female), and 2) converters (i.e., dementia at follow-up; n = 69, 75 ± 7, 30 % female) who were matched on baseline age and Mini-Mental State Examination scores. Groups were compared on FreeSurfer generated baseline GWR from structural images in which higher values represent greater tissue contrast. A general linear model, adjusting for APOE-status, scanner type, hippocampal volume, and cortical thickness, revealed that converters evidenced lower GWR values than non-converters (i.e., more degradation in tissue contrast; p = 0.03). Individuals with MCI who convert to dementia have lower baseline GWR values than individuals who remain diagnostically stable over a 3-year period, statistically independent of cortical thickness or hippocampal volume.
Vanderbilt Memory & Alzheimer's Center, Department of Neurology, Vanderbilt University Medical Center, 2525 West End Avenue, 12th Floor - Suite 1200, Nashville, TN, 37203, USA, angela.jefferson@vanderbilt.edu.
Angela L
AL
Jefferson
Katherine A
KA
Gifford
Stephen
S
Damon
G William
GW
Chapman
Dandan
D
Liu
Jamie
J
Sparling
Vitaly
V
Dobromyslin
David
D
Salat
D000368:Aged; D001284:Atrophy / Q000473:pathology; D001921:Brain / Q000473:pathology*; D060825:Cognitive Dysfunction / Q000473:pathology*; D066264:Datasets as Topic; D003704:Dementia / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D066128:Gray Matter / Q000473:pathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D009929:Organ Size; D012984:Software; D066127:White Matter / Q000473:pathology*