Perineurial (Tarlov) cysts are meningeal dilations of the posterior spinal nerve root sheath that most often affect
sacral roots and can cause a progressive painful radiculopathy. Tarlov cysts are associated with a variety of radiological findings. Initial plain radiographic examination may reveal Tarlov cysts causing erosion of the sacrum, bone scalloping, or a rounded paravertebral shadow. These cysts have CSF-like characteristics
on MR imaging—that is, a low signal on T1- weighted images and a high signal on T2-weighted images. Magnetic resonance imaging can also be used to delineate the exact relationship of the cyst to the thecal sac, as well as the total volume of fluid within the cyst. They are most often asymptomatic but can cause radiculopathy.
sacral roots and can cause a progressive painful radiculopathy. Tarlov cysts are associated with a variety of radiological findings. Initial plain radiographic examination may reveal Tarlov cysts causing erosion of the sacrum, bone scalloping, or a rounded paravertebral shadow. These cysts have CSF-like characteristics
on MR imaging—that is, a low signal on T1- weighted images and a high signal on T2-weighted images. Magnetic resonance imaging can also be used to delineate the exact relationship of the cyst to the thecal sac, as well as the total volume of fluid within the cyst. They are most often asymptomatic but can cause radiculopathy.