When pain in the low back does not respond to the basic treatments it may be necessary to investigate the inter vertebral discs as possible pain generating structures.
Painful discs can be bulging or have tears, but often discs that look normal on X-rays or MRI may be painful.
The procedure usually takes about 30 minutes.
A small needle is guided into the center of the discs and dye is injected while X-rays are being taken and intra disc pressure is measured.
The disc is said to be a cause of pain, if injections produces pain which is same as your usual pain.