Heterogeneity of blood‐brain barrier changes in multiple sclerosis

Abstract

We performed 15 dynamic gadolinium-DTPA (Gd-DTPA)-enhanced MRI studies in 8 patients with relapsing and remitting multiple sclerosis; 7 were follow-up studies. We measured the time course of enhancement in 102 enhancing lesions for up to 384 minutes, with rest breaks. Immediate postcontrast MRIs demonstrated many different patterns of enhancement. We observed both uniformly enhancing and ring enhancing lesions. The enhancing regions were often less extensive than the corresponding high signal on T2-weighted images. Three lesions were seen with Gd-DTPA but not on unenhanced scans; 1 was seen on unenhanced scans 10 days later, suggesting that blood-brain barrier disturbance may precede other MRI signs of MS lesions. Three months later, some high-signal areas on T2-weighted scans had decreased in size to resemble the areas previously outlined by Gd-DTPA. This technique provides useful information about the pathogenesis and behavior of MS lesions.

Epilepsy in Patients with Multiple Sclerosis: Radiological‐Clinical Correlations

“…Serial MRI studies (7,20) have shown that new plaques increase in size in a period of 6 weeks and then decrease slowly. This time period and the T,-weighted MRI features suggest that edema may play a role (1 8).…”

“…Using MRI, we evaluated the localization of the plaques. Because it is difficult to differentiate cortical and subcortical lesions in patients with MS, we used the contrast agent gadolinium (7). MRI also demonstrated the frontal atrophy and the size of the corpus callosum.…”

Quantification of cerebral blood flow, cerebral blood volume, and blood–brain‐barrier leakage with DCE‐MRI

“…[18,25]), producing maps of F B , T P , and E. To calculate the extraction flow F E from Eqs. [19], the plasma flow F P was calculated as (1 − Hct)F B with a fixed hematocrit value of Hct = 0.45. A ROI covering the lesion was drawn manually on the F E map and superposed on the F B map to exclude areas of necrosis and larger blood vessels.…”

“…DCE-MRI is the method of choice for the measurement of permeability (18)(19)(20), but CBV and CBF measurement is problematic because the signal changes induced by the intravascular component of the tracer are small (21). The problem originates from a combination of two factors: T 1 -relaxivities (22) are an order of magnitude smaller than for T * 2 (8), and the small blood volumes in brain tissue (23) do not allow for large tissue concentrations.…”

Population-Wide Model-Free Quantification of Blood-Brain-Barrier Dynamics in Multiple Sclerosis

“…The analysis of contrast-agent uptake can provide only limited insight into these issues. Dynamic-contrast-enhanced MRI (DCE-MRI) has been used for the past two decades to quantify the rate at which contrast agents pass from the plasma to MS lesions as a measure of BBB permeability [Kermode et al, 1990]. DCE-MRI data are typically analyzed using deterministic pharmacokinetic modeling techniques based on multi-compartment tissue models with exchange [Davidian and Giltinan, 1995].…”