Abstract:
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Purpose: There is histopathologic evidence that inflammation within cerebral venules may occur in areas of normal-appearing white matter (NAWM) in multiple sclerosis (MS). Dynamic contrast-enhanced T2*-weighted perfusion MR imaging (pMRI) has been used to study microvascular alterations in various intracranial processes. The purpose of this study was to determine hemodynamic changes in the NAWM of patients with relapsing-remitting MS (RR-MS) using pMRI.
Methods and Materials: Conventional MR imaging and dynamic contrast-enhanced T2-weighted pMRI was performed in seventeen patients with RR-MS and sixteen controls. Absolute cerebral blood volume (CBV), absolute cerebral blood flow (CBF), and mean transit time (MTT) (each referenced to an arterial input function), and relative cerebral blood flow (rCBV, referenced to contralateral NAWM), were determined in periventricular, intermediate, and subcortical regions of NAWM at the level of the lateral ventricles. Least squares regression was used to compare RR-MS patients and controls with respect to perfusion measures in each region after adjusting for differences attributable to age and gender. Repeated measure analysis of variance and Tukey's honesty significant difference (HSD) procedure was used to pairwise compare brain regions in terms of each perfusion measure.
Results: Each region of NAWM in RR-MS patients had significantly increased MTT compared to the corresponding region in controls. The periventricular and subcortical NAWM had decreased CBF compared to the corresponding regions in controls. No significant differences in CBV and rCBV were found between RR-MS patients and controls in any of the corresponding areas of NAWM examined. In controls, significant regional differences were found in CBF, CBV, and rCBV, with periventricular NAWM demonstrating significantly higher CBF, CBV, and rCBV than intermediate and subcortical regions. In RR-MS patients, significant differences were found in the CBV and rCBV but not CBF or MTT. The periventicular NAWM demonstrated higher CBV and rCBV.
Conclusion: The NAWM of patients with RR-MS demonstrates decreased perfusion (decreased CBF and increased MTT) compared to that of controls. This may reflect a primary pathologic process such as cerebral vasculitis, or may be secondary to decreased metabolic demand from diffuse microscopic parenchymal pathology. Auto-regulation is able to maintain CBV above frankly ischemic levels.
Questions about this event email: lawm01@med.nyu.edu
Saindane MD, A,
Microvascular Abnormality in Relapsing-Remitting Multiple Sclerosis: Perfusion MR Imaging Findings in the Normal Appearing White Matter. Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL.
http://archive.rsna.org/2003/3105456.html
