Increasing power to predict mild cognitive impairment conversion to Alzheimer's disease using hippocampal atrophy rate and statistical shape models
Identifying mild cognitive impairment (MCI) subjects who will convert to clinical Alzheimer's disease (AD) is important for therapeutic decisions, patient counselling and clinical trials. Hippocampal volume and rate of atrophy predict clinical decline at the MCI stage and progression to AD. In this paper, we create p-maps from the differences in the shape of the hippocampus between 60 normal controls and 60 AD subjects using statistical shape models, and generate different regions of interest (ROI) by thresholding the p-maps at different significance levels. We demonstrate increased statistical power to classify 86 MCI converters and 128 MCI stable subjects using the hippocampal atrophy rat…
The EADC-ADNI Harmonized Protocol for manual hippocampal segmentation on magnetic resonance : Evidence of validity
BackgroundAn international Delphi panel has defined a harmonized protocol (HarP) for the manual segmentation of the hippocampus on MR. The aim of this study is to study the concurrent validity of the HarP toward local protocols, and its major sources of variance.MethodsFourteen tracers segmented 10 Alzheimer's Disease Neuroimaging Initiative (ADNI) cases scanned at 1.5 T and 3T following local protocols, qualified for segmentation based on the HarP through a standard web-platform and resegmented following the HarP. The five most accurate tracers followed the HarP to segment 15 ADNI cases acquired at three time points on both 1.5 T and 3T.ResultsThe agreement among tracers was relatively low…
Prevalence and Cognitive Impact of Medial Temporal Atrophy in a Hospital Stroke Service: Retrospective Cohort Study
Background Cerebrovascular disease and neurodegeneration cause cognitive impairment and frequently coexist. Aims Our objectives were to investigate the prevalence and cognitive impact of medial temporal lobe atrophy – a radiological marker often associated with Alzheimer's disease – in a hospital stroke service. Methods Retrospective cohort study of patients from a hospital stroke service. Patients assessed for suspected ischemic stroke or transient ischemic attack, irrespective of final diagnosis, underwent neuropsychological testing and magnetic resonance imaging. medial temporal lobe atrophy, white matter hyperintensities, lacunes, and cerebral microbleeds were rated using established cr…