Background: Early blood–brain barrier damage after acute intracerebral hemorrhage (ICH) has been qualitatively linked to subsequent perihematoma edema (PHE) formation. In this quantitative study, it was investigated whether the degree of blood–brain barrier damage evident on MRI scans was related to ICH and PHE volume in patients with acute ICH.
Methods: Analysis was performed on a database of patients with acute ICH who underwent perfusion-weighted imaging (PWI) with gadolinium within 7 days of ICH onset. Postprocessing of the PWI source images was performed to estimate changes in blood–brain barrier permeability ipsilaterally within the perihematoma region and contralaterally in regions of chronic white matter disease. Mean permeability derangement (MPD) was calculated in these two regions of interest (ROI) for each patient by taking the mean of all voxels within the ROI that were two standard deviations above normal. Normal tissue was defined by an ROI selected in the contralateral hemisphere that did not have any chronic disease. MPD is expressed as a percent of gadolinium leakage compared to this intact tissue. CT images within 48 hours of MRI were analyzed for ICH and PHE volumes using computerized volumetrics.
Results: Twenty-two patients were identified, 16 of whom experienced hypertenisve ICH, and 6 of which were classified as other etiology. The MPD (±SDs) was 14.9.±16.4% ipsilateral to ICH, 14.8±21.6% on the contralateral side (P=0.64). PHE volume was significantly associated with perihematoma MPD (β=10.49 [1.11 to 19.86]) and ICH volume (β=0.84 [0.77 to 0.92]). Permeability was non-significantly higher in patients with intraventricular hemorrhage extension (18.6±29.7% vs. 14.0±13.2%) and with systemic infection (24.2±23.9% vs. 12.2±13.8%). Permeability was not correlated with low density lipoprotein level or statin use.
Conclusions: A perfusion-weighted imaging–derived index of blood–brain barrier damage measured during acute ICH detected focal increases in permeability of the perihematoma region and contralateral hemisphere, and was significantly associated with perihematoma edema volume.