1) Description of Measurement

The High-Intensity Zone (HIZ) is defined as a focal area of increased signal intensity within the posterior annulus fibrosus on T2-weighted MRI that is clearly distinct from the nucleus pulposus. It represents an annular fissure/tear and is strongly associated with discogenic low-back pain, particularly when concordant with patient symptoms.

2) Instructions to Measure

• Scroll through the mid-sagittal and parasagittal T2 sequences of the lumbar spine.

• Identify a well-defined hyperintense focus located within the posterior annulus fibrosus, separate from the nucleus pulposus.

• Confirm the lesion:

• Appears on at least two adjacent slices, and

• Is brighter than nucleus pulposus on T2-weighted imaging.
  
  

• Record:

• Disc level (e.g., L4–5)

• Location (central, right or left posterolateral)

• Presence or absence of HIZ (binary variable).

3) Normal vs. Pathologic Ranges

• Absent: Normal annulus

• Focal T2 hyperintensity in posterior annulus: Annular fissure / HIZ

4) Important References

5) Other info....