The clinical use of structural MRI in Alzheimer disease

Abstract

MRI-based structural imaging has become an integral component of the clinical assessment of patients with suspected Alzheimer disease (AD), and atrophy of medial temporal structures is now considered to be a valid diagnostic marker at the mild cognitive impairment stage. In this article, Frisoni et al. consider the roles of structural MRI markers in the diagnosis of AD and non-AD dementias, and in the tracking of disease progression during clinical trials. Structural imaging based on magnetic resonance is an integral part of the clinical assessment of patients with suspected Alzheimer dementia. Prospective data on the natural history of change in structural markers from preclinical to overt stages of Alzheimer disease are radically changing how the disease is conceptualized, and will influence its future diagnosis and treatment. Atrophy of medial temporal structures is now considered to be a valid diagnostic marker at the mild cognitive impairment stage. Structural imaging is also included in diagnostic criteria for the most prevalent non-Alzheimer dementias, reflecting its value in differential diagnosis. In addition, rates of whole-brain and hippocampal atrophy are sensitive markers of neurodegeneration, and are increasingly used as outcome measures in trials of potentially disease-modifying therapies. Large multicenter studies are currently investigating the value of other imaging and nonimaging markers as adjuncts to clinical assessment in diagnosis and monitoring of progression. The utility of structural imaging and other markers will be increased by standardization of acquisition and analysis methods, and by development of robust algorithms for automated assessment.