Lumbar Annular High-Intensity Zone as a Precursor to Disc Extrusion

Low back pain (LBP) is a common affliction with numerous causes. Some individuals experience LBP attributed to disc pathology. Disc pathology has been implicated in a plurality of cases of LBP, and some cases are associated with annular fissures (AFs). AFs are weaknesses in the structure that contains the nucleus pulposus and is the site of possible disc herniations. On magnetic resonance imaging (MRI), some AFs manifest as the high-intensity zone (HIZ), otherwise known as an annular enhancement region. In this report, we present three patients with LBP, mild radiculitis, and HIZ who later developed herniated nucleus pulposus (HNP) with extrusion through the HIZ. These cases suggest that HIZ indicates a propensity for the future development of disc extrusion through the weakened tissue at the AF visualized as HIZ on MRI. With a better understanding of the association between AFs and disc herniations with HIZ, clinicians may be able to predict and prevent the pain and disability associated with disc extrusion.