Walter Koch, Presenter: Nothing to Disclose

Thomas Michael Meindl MD, Abstract Co-Author: Nothing to Disclose

Stefan Teipel MD, Abstract Co-Author: Nothing to Disclose

Sophia Mueller, Abstract Co-Author: Nothing to Disclose

Maximilian F. Reiser MD, Abstract Co-Author: Nothing to Disclose

Functional MRI (fMRI) of default mode network (DMN) brain activity during resting is recently gaining attention as a potential non-invasive biomarker to diagnose incipient Alzheimers disease. Aim of this study was to determine, which method of data processing provides highest diagnostic power and to define metrics to further optimize the diagnostic value.

fMRI was acquired in 21 healthy subjects, 17 patients with MCI and 15 patients with AD and data evaluated both with volumes of interest (VOI) based signal time course correlation evaluations and independent component analyses (ICA). The first approach determines the amount of DMN region interconnectivity (as expressed with correlation coefficients), the second method determines the magnitude of DMN co-activation.

Diagnostic power (expressed as accuracy) of data of a single DMN region in independent component analyses was 64%, that of a single correlation of time courses between two DMN regions was 71%, respectively. With multivariate analyses combining both methods of analyses and data from various region, accuracy could be increased to 97% (Sensitivity 100%, specificity 95%).

Time course correlation analyses outperform independent component analyses in the identification of patients with Alzheimer’s disease. However, multivariate analyses combining both methods of analysis by considering the activity of various parts of the DMN as well as the interconnectivity between these regions are required to achieve optimal and clinically acceptable diagnostic power.

Knowledge of optimized metrics is essential to obtain clinical acceptable diagnostic power when applying fMRI as a non-invasive biomarker for incipient Alzheimer's disease.

Koch, W, Meindl, T, Teipel, S, Mueller, S, Reiser, M, Diagnostic Power of Default Mode Network Activity in Resting State fMRI in the Detection of Alzheimer’s Disease: Does the Method of Analysis Matter?.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8009360.html