Comparison of MR signal intensities of cerebral perivascular (Virchow-Robin) and subarachnoid spaces

Purpose: The purpose of this work was to compare quantitatively the T2-weighted MR signal intensity values of the perivascular (Virchow-Robin) spaces and the cerebrospinal fluid (CSF). Method: Coronal 3D T2-weighted turbo spin echo MR images of the brain Acre evaluated in 44 subjects without any significant cerebral pathology. MR signal intensity values of the perivascular spaces around the anterior commissure and the CSF in the ventricles and the subarachnoid space were measured. Results: A statistically significant difference between the mean MR signal intensity values of the perivascular spaces and the CSF both in the ventricles and in the subarachnoid space was found. The intensity values in the ventricles and in tile subarachnoid space were not statistically significantly different. Conclusion: The perivascular spaces have a different MR signal intensity than the CSF-containing structures within and around the brain. This finding is in keeping with the statement that the perivascular spaces represent entrapments of interstitial fluid and are not the invagination of CSF-filled subarachnoid sheaths.