Elevated Cerebral Blood Flow and Volume in Systemic Lupus Measured by Dynamic Susceptibility Contrast Magnetic Resonance Imaging

Abstract

Studies that have examined abnormalities in cerebral blood flow (CBF) in patients with systemic lupus erythematosus (SLE) reported CBF relative to a region assumed to be normal in the brain. We examined the absolute differences in both regional CBF and cerebral blood volume (CBV) between patients with SLE and healthy controls. CBF and CBV were measured with dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI), a technique that provides an alternative to radionuclide perfusion studies and permits quantitative anatomic, CBF, and CBV imaging in a single scanning session. CBF and CBV were measured in lesions and in normal-appearing tissue in the major cerebral and subcortical brain regions. Unlike most perfusion studies in SLE, CBF and CBV values were not normalized to a region of the brain assumed to be healthy. CBF and CBV within MRI-visible lesions were markedly reduced relative to surrounding normal-appearing white matter. CBF and CBV in normal-appearing tissue were both higher in SLE patient groups, with or without lesions, relative to the control group. DSC MRI, without normalization to a region presumed to be healthy, revealed that CBF and CBV in normal-appearing tissue in patients with SLE was higher than CBF and CBV in controls. Since this finding was made in subgroups of patients with and without lesions, the higher CBF and CBV appear to precede lesion pathology.