How many mm should the thecal sac be?

How many mm should the thecal sac be?

SAC Measurements of: > 18 mm = normal. 15 to 17 mm = possible abnormality. < 14 mm = concerning for spinal cord compression.

How many mm is severe spinal stenosis?

A sagittal diameter of 12 mm is considered as narrow (relative stenosis) and a diameter of 10 mm or less is considered a severely narrowed (absolute stenosis) according to Verbiest.

At what level does the thecal sac typically terminate?

Neural Anatomy. The thecal sac ends blindly at the S2 level. The lower sacral and coccygeal nerves emerge from the sac, as does the extradural portion of the filum terminale. The upper four roots exit the sacrum through the paired ventral and dorsal sacral foramina.

How many mm is a normal spinal canal?

The anteroposterior (AP) diameter of the normal adult male cervical canal has a mean value of 17-18 mm at vertebral levels C3-5. The lower cervical canal measures 12-14 mm.

What happens when the thecal sac is compressed?

If there is central stenosis and marked compression of the entire dural/thecal sac, the patient may demonstrate paralysis (e.g., cauda equina syndrome) with sphincter loss (bladder and rectal dysfunction).

What is a thecal sac in back?

Thecal sac is the outer covering of the spinal cord. This means there are bone spurs on the back of the spinal bones, putting pressure on or affecting the front part of the outer layer of the (neck) cervical spinal cord.

Does thecal sac compression cause pain?

Metastatic epidural spinal cord compression is a common complication of cancer that can cause pain and potentiaLly irreversible loss of neurologic function. In most cases this syndrome is caused by compression of the thecal sac and the spinal cord by extradural metastatic mass.

What does AP thecal sac mean?

The thecal sac or dural sac is the membranous sheath (theca) or tube of dura mater that surrounds the spinal cord and the cauda equina. The thecal sac contains the cerebrospinal fluid which provides nutrients and buoyancy to the spinal cord.

What does the thecal sac do?

What makes up the lining of the thecal sac?

The thecal sac is a covering of the spinal canal that is filled with cerebrospinal fluid (CSF). It houses the spinal cord and nerve roots. It is made up of outer arachnoid membrane and inner dura.

Is the thecal sac part of the spinal cord?

The thecal sac is a covering of the spinal canal that is filled with cerebrospinal fluid (CSF). It houses the spinal cord and nerve roots. It is made up of outer arachnoid membrane and inner dura. It is wider in females. The length is approximately until S1 to S3 vertebral levels.

What does SAC stand for in medical terms?

SAC stands for “Space Available for the Cord” and is calculated by subtracting the sagittal diameter of the spinal cord from the sagittal diameter of the spinal canal. The sagittal spinal cord diameter is measure from the posterior wall of the vertebral body (half way down) to the laminar line.

Why is thecal sac wider in women than in men?

Thecal sac varies in both genders. In women, the sac is wider than in men. Thecal sac surrounds the cerebrospinal fluid which ensures that your spine is functioning effectively. Since thecal sac houses spinal cord and cauda equina, it cushions them against damage from other spinal structures.