Radiology 2002 Jul;224(1):184-92
Lowe MJ, Phillips MD, Lurito JT, Mattson D, Dzemidzic M, Mathews VP.
Departments of Radiology (M.J.L., M.D.P., J.T.L., M.D., V.P.M.) and Neurology (D.M.), Indiana University School of Medicine, CL 157, 541 Clinical Dr, Indianapolis, IN 46202-5111.
To study the correlation of low-frequency blood oxygenation level-dependent (BOLD) fluctuations on magnetic resonance (MR) images obtained of the left- and right-hemisphere primary motor regions in healthy control subjects and patients with multiple sclerosis (MS).
MATERIALS AND METHODS:
Sixteen healthy volunteers and 20 patients with MS underwent MR imaging with a 1.5-T imager by using a protocol designed to monitor low-frequency BOLD fluctuations. Data for low-frequency BOLD fluctuations were acquired with subjects at rest and during continuous performance of a bilateral finger-tapping task. These data were low-pass filtered (<0.08 Hz), and cross correlations of all acquired pixels to a region of interest in the left precentral gyrus were calculated. Confidence levels were calculated from the cross correlations. The fraction of pixels in the right precentral gyrus above a confidence level of 95% for correlation with the left precentral gyrus was calculated for each subject.
A plot of the fraction of the right precentral gyrus with high correlation with the left precentral gyrus for the finger-tapping state versus the resting state showed a clear discrimination between patients with MS and control subjects. Compared with control subjects, patients with MS generally had a smaller fraction of the pixels in the right precentral gyrus above the confidence level. This finding indicates that our method results in greater than 60% sensitivity and 100% specificity for discriminating patients with MS from control subjects. No significant correlation was found between clinical measures of MS disease and correlations of low-frequency BOLD fluctuations between left and right precentral gyri.
On the basis of the connectivity measure of low-frequency BOLD fluctuations, patients with MS exhibited lower functional connectivity between right- and left-hemisphere primary motor cortices when compared with that in control subjects.
Copyright RSNA, 2002