page_title: Tarlov cyst
section_title: MRI
hierarchical_section_title: Tarlov cyst / Diagnosis / MRI
caption_attribution_description: English: MRI sagittal image of sacral and dorso-lumbar perineural cysts
context_page_description: Tarlov cysts, are type II innervated meningeal cysts, cerebrospinal-fluid-filled sacs most frequently located in the spinal canal of the S1-to-S5 region of the spinal cord, and can be distinguished from other meningeal cysts by their nerve-fiber-filled walls. Tarlov cysts are defined as cysts formed within the nerve-root sheath at the dorsal root ganglion. The etiology of these cysts is not well understood; some current theories explaining this phenomenon have not yet been tested or challenged but include increased pressure in CSF, filling of congenital cysts with one-way valves, inflammation in response to trauma and disease. They are named for American neurosurgeon Isadore Tarlov, who described them in 1938.
  Tarlov cysts are relatively uncommon when compared to other neurological cysts. Initially, Isadore Tarlov believed them to be asymptomatic, however as his research progressed, Tarlov found them to be symptomatic in a number of patients. These cysts are often detected incidentally during MRI or CT scans for other medical conditions. They are also observed using magnetic resonance neurography with communicating subarachnoid cysts of the spinal meninges.
context_section_description: MRI, or Magnetic Resonance Imaging, is considered the imaging study of choice in identifying Tarlov cysts. MRI provides better resolution of tissue density, absence of bone interference, multiplanar capabilities, and is noninvasive. Plain films may show bony erosion of the spinal canal or of the sacral foramina
  On MRI pictures, the signal is the same as the CSF one.
  If MRI made with a contrast medium:
  The signal in the cyst is the same as in the dural bag.
  The signal for cysts due to traumas…is a little stronger at the periphery or nerve root location
  The signal is more important for other causes: synovial cysts, dermoïdes or épidermoïdes cysts, teratomes
caption: MRI sagittal image of sacral and dorso-lumbar perineural cysts.
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