Owen Carmichael, Ph.D.
Associate Professor and Director of Biomedical Imaging
Associate Professor and Director of Biomedical Imaging
Alzheimer’s disease (AD) is characterized by an insidious loss of cognitive function over time, but the rate of cognitive decline varies widely from person to person. We are trying to understand the variability in cognitive decline rates by examining relationships between rates of cognitive decline and regions of interest in the brain. We are using fully-automated image processing techniques to isolate those regions of interest in structural MR images.
In a series of studies, we used fully-automated segmentation techniques to isolate the lateral ventricles (shown at upper left) in subjects who received MR images in 1998 as part of the Cardiovascular Health Study. The subjects received clinical evaluations in 1998 and 2002, and were placed into categories according to their rates of cognitive decline between 1998 and 2002. Among subjects who were normal in 1998, we found that those who rapidly declined to dementia by 2002 (represented by the magenta curve below) had larger lateral ventricles in 1998 than subjects who stayed normal (red curve) or subjects who declined to a transitional state known as mild cognitive impairment (MCI, orange curve). We hope that by understanding relationships between cognitive decline rates and brain structure characteristics, we could be able to predict and treat cognitive decline more effectively.
O. T. Carmichael, L. H. Kuller, O. L. Lopez, P. M. Thompson, A. Lu, S. E. Lee, J. Y. Lee, H. J. Aizenstein, C. C. Meltzer, Y. Liu, A. W. Toga, J. T. Becker.Ventricular volume and dementia progression in the Cardiovascular Health Study. Neurobiology of Aging, V. 28 (3), February 2007, pp 389-397.eScholarship PDF, DOI
O. T. Carmichael, L. H. Kuller, O. L. Lopez, P. M. Thompson, R. A. Dutton, A. Lu, S. E. Lee, J. Y. Lee, H. J. Aizenstein, C. C. Meltzer, Y. Liu, A. W. Toga, J. T. Becker. Cerebral Ventricular Changes Associated With Transitions Between Normal Cognitive Function, Mild Cognitive Impairment, and Dementia. Alzheimer's Disease and Associated Disorders, January/March 2007;21(1):14-24. Link , eScholarship PDF.
O. T. Carmichael, L. H. Kuller, O. L. Lopez, P. M. Thompson, R. A. Dutton, A. Lu, S. E. Lee, J. Y. Lee, H. J. Aizenstein, C. C. Meltzer, Y. Liu, A. W. Toga, J. T. Becker. Acceleration of cerebral ventricular expansion in the Cardiovascular Health Study. Neurobiology of Aging, September 2007; 28 (9): 1316-1321. DOI, eScholarship PDF
O. T. Carmichael, P. M. Thompson, R. A. Dutton, A. Lu, S. E. Lee, J. Y. Lee, L. H. Kuller, O. L. Lopez, H. J. Aizenstein, C. C. Meltzer, Y. Liu, A. W. Toga, J. T. Becker. Mapping Ventricular Changes Related to Dementia and Mild Cognitive Impairment in a Large Community-Based Cohort. Proceedings, IEEE International Symposium on Biomedical Imaging, April 2006, pp. 315-318. DOI