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The intervertebral disc is composed of an outer capsule, the annulus fibrosis, which surrounds the inner nucleus pulposus. A tear of this capsule, called an annular tear, allows the nucleus pulposus to escape, in some cases producing a visible bulge. This can usually be seen on the MRI with careful inspection. Some patients, however, on routine MRI exam appear to have normal discs but continue to experience severe symptoms which duplicate the normal symptoms reported with disc protrusion. It is now known that these symptoms can be due to an annular tear which allows the inflammatory contents of the disc to escape, even without an obvious disc bulge. Annular tears such as this can be diagnosed with enhanced MRI scans or with a technique called discography. Discography involves injecting the disc with dye; patients with an annular tear will demonstrate leakage of the dye through the tear. Patients with annular tears are frequently not diagnosed properly for years. This is somewhat understandable because often their routine MRIs are read as normal and a discogram, which is not a comfortable procedure, has not been done.