Abstract
BackgroundVisual assessment rating scales for medial temporal lobe (MTL) atrophy have been used by neuroradiologists in clinical practice to aid the diagnosis of Alzheimer's disease (AD). Recently multivariate classification methods for magnetic resonance imaging (MRI) data have been suggested as alternative tools. If computerized methods are to be implemented in clinical practice they need to be as good as, or better than experienced neuroradiologists and carefully validated. The aims of this study were: (1) To compare the ability of MTL atrophy visual assessment rating scales, a multivariate MRI classification method and manually measured hippocampal volumes to distinguish between subjects with AD and healthy elderly controls (CTL). (2) To assess how well the three techniques perform when predicting future conversion from mild cognitive impairment (MCI) to AD.MethodsHigh resolution sagittal 3D T1w MP-RAGE datasets were acquired from 75 AD patients, 101 subjects with MCI and 81 CTL from the multi-centre AddNeuroMed study. An automated analysis method was used to generate regional volume and regional cortical thickness measures, providing 57 variables for multivariate analysis (orthogonal partial least squares to latent structures using seven-fold cross-validation). Manual hippocampal measurements were also determined for each subject. Visual rating assessment of MTL atrophy was performed by an experienced neuroradiologist according to the approach of Scheltens et al.ResultsWe found prediction accuracies for distinguishing between AD and CTL of 83% for multivariate classification, 81% for the visual rating assessments and 89% for manual measurements of total hippocampal volume. The three different techniques showed similar accuracy in predicting conversion from MCI to AD at one year follow-up.ConclusionVisual rating assessment of the MTL gave similar prediction accuracy to multivariate classification and manual hippocampal volumes. This suggests a potential future role for computerized methods as a complement to clinical assessment of AD.
Highlights
Dementia is the third most common cause of death in society today, exceeded only by cancer and cardiovascular disorders and Alzheimer’s disease (AD) is the most common form of dementia.Biomarkers of AD based on non-invasive in vivo methods are highly desirable for diagnosis, monitoring disease progression and evaluating disease-modifying treatment strategies
To better compare the performance of the three methods we calculated the sensitivity (MCI-c predicted as AD) at a fixed specificity (MCI-s predicted as CTL)
Classification accuracy of the different techniques The results suggest that the orthogonal partial least squares to latent structures (OPLS) technique with fully automated regional magnetic resonance imaging (MRI) measures as input performs better than the visual rating assessments made by an experienced neuroradiologist
Summary
Dementia is the third most common cause of death in society today, exceeded only by cancer and cardiovascular disorders and Alzheimer’s disease (AD) is the most common form of dementia.Biomarkers of AD based on non-invasive in vivo methods are highly desirable for diagnosis, monitoring disease progression and evaluating disease-modifying treatment strategies. Several groups including our own have proposed the use of multivariate techniques for analyzing multiple regional measures from MRI to aid diagnosis of AD and to predict future conversion from the prodromal stages of the disease often referred to as mild cognitive impairment (MCI) to AD. If computerized methods based on MRI are to be useful in clinical practice they will need to be as good as or better than experienced neuroradiologists. Visual assessment rating scales for medial temporal lobe (MTL) atrophy have been used by neuroradiologists in clinical practice to aid the diagnosis of Alzheimer’s disease (AD). The aims of this study were: (1) To compare the ability of MTL atrophy visual assessment rating scales, a multivariate MRI classification method and manually measured hippocampal volumes to distinguish between subjects with AD and healthy elderly controls (CTL). The aims of this study were: (1) To compare the ability of MTL atrophy visual assessment rating scales, a multivariate MRI classification method and manually measured hippocampal volumes to distinguish between subjects with AD and healthy elderly controls (CTL). (2) To assess how well the three techniques perform when predicting future conversion from mild cognitive impairment (MCI) to AD
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
