Presentation
Chronic headaches.
Patient Data
Noncontrast CT head shows CSF density lesions of various sizes in the right lentiform nucleus and thalamus. No associated perilesional edema.
CSF intensity lesions of various sizes noted in the right lentiform nucleus and thalamus. The lesions do not demonstrate restricted diffusion or enhancement. The largest lesion is centered in the right temporal stem. There is no perilesional vasogenic edema.
Case Discussion
Perivascular spaces are pial lined interstitial fluid filled spaces that accompany penetrating arteries. They do not have direct connection with the subarachnoid space.
They are variable sized and well-circumscribed, and are most commonly seen in the basal ganglia.
They are usually less than 5mm, but can become quite large and cause mass effect. These giant perivascular spaces are often seen in the midbrain.