Enhancement of virchow-robin spaces. An MRI evaluation.

Virchow-Robin spaces are enclosed spaces filled with interstitial fluid and covered with pia that accompany arteries, arterioles, veins and venules as they perforate the brain. They are round, linear or punctuate areas depending on the image that parallel cerebrospinal fluid attenuation or signal intensity. They are classically described as isointense to cerebrospinal fluid on images obtained with all pulse sequences. They appear hypointense relative to brain on T1-weighted MR scans and present a high signal intensity on T2-weighted MR scans. They also show complete signal suppression on fluid-attenuated inversion recovery (FLAIR) scans and no enhancement after intravenous contrast administration. However, many pathologic states result in abnormal dilation with an increased number of Virchow-Robin spaces visible on MRI imaging and many pathological conditions cause the spaces to enhance. The purpose of this study is to present the major causes of Virchow-Robin enhancement.