[Imaging of perivascular spaces of the brain: MR-clinical correlation]

1. We evaluated the perivascular spaces(PVS) of the intraparenchymal arteries of the brain obtained from MRI, and compared them with the microangiograms of the injected autopsied brains of normal adults. 2. The three dimensional microangiograms revealed 3 types of intraparenchymal arteries: intracortical, subcortical(including arteries of arcuate fibers) and medullary arteries. PVS of those arteries had punctuated or small linear-shaped appearances according to the dimension and level of MR slices. 3. Basic MR findings of normal PVS showed smooth and well-defined round or elliptical configurations up to 3 mm in diameter without a halo in the surrounding tissue, located along the intraparenchymal arteries, and isointense with cerebro-spinal fluid. 4. PVS around the medullary arteries was dilated with age. Definite PVS was found in the lower portion of the basal ganglia in almost all healthy children and relatively young adults, however, it was less frequent in the subcortical white matter of frontal and parietal lobes. In adults over 60 years of age, dilatation of PVS along the medullary arteries was quite common and progressed into the frontal and parietal lobes. 5. Dilatation of PVS around the medullary arteries was prominent and increased with the number of lacunar infarcts. The sclerotic change of medullary arteries was more accelerated in subjects with hypertension.