Discography

This is an investigation performed when the patient has spinal pain either in the low back or neck.  It requires the patient to be admitted to the hospital for the day, or overnight.  

The procedure is undertaken using x-ray control to allow very accurate placement of needles into the discs themselves.  This part can be performed under local anaesthetic or under a quick general anaesthetic. After this the doctor injects the disc with a radio-opaque contrast material, which allows two factors to be identified:-

1    Any tears in the disc can be seen on the x-rays and subsequent CT scan. 

2    The pressure in the disc can be determined

The patient is awake for the injection itself.  If the disc is normal, the patient feels virtually nothing (occasionally a little tightness only).  If the disc is the cause of the typical pain, then the injection will characteristically reproduce that pain, at a pressure of less than 20 psi (pounds per square inch) above the opening pressure of the disc. This tells the doctor that the pain source has been accurately identified. 

Often the symptoms are flared up for one to two days after this procedure. There is a risk of introducing infection when the skin is punctured; with discography this risk is quoted at 0.4% per needle. A disc space infection ("discitis") needs long term antibiotics and may cause a lot more pain.

Needles are seen here inserted into the discs and the contrast is clearly seen on an x-ray image.

The contrast can be seen leaking at the back of the disc (arrow) - a posterior tear in the disc annulus

To see more pictures of discography click here.