High Intensity Zone

High Intensity Zone (HIZ) – Posterior Annulus

A high intensity zone should not be overlooked-especially with a symptomatic patient. This is a bright white finding on MRI, most notable on the posterior annulus.

High Intensity Zone

In a recent study in The Journal of Medical Investigation, researchers looked at the pathogenesis of low back pain (with and without leg pain) and described it being caused by annular fissures and disc degeneration. 1 2.

Here are some key point of the research:

  1. They identified that more than two-thirds of the high intensity zones were found in the lower lumbar motion segments with the most at L4-5 followed by L5-1.
  2. They commented that they were unable to determine whether the intensity of the MRI magnet played a role in distinguishing HIZs.
  3. It is important to identify reliable measures to find HIZs.
  4. New treatment strategies are developing for the treatment of HIZ including laser.
  5. HIZs are not only a measure of degeneration but an active inflammatory tissue.

Dynamic Disc Designs develope models to help identify the movements that can stress the posterior annulus. Visit the Professional LxH Model to see an example of a high intensity zone.

High Intensity Zone, HIZ, Lumbar Disc


  1. Rozen D. Discogenic Low Back Pain. Pain Prac. 1: 278-86, 2007
  2. Peng B, Zhang Y, Hou S, Wu W, Fou X : Intradiscal Methylene blue injection for the treatment of chronic discogenic low back pain. Pain. 149 : 124-9 2010