Three types of annular fissures are illustrated:
transverse - a fissure in the axial plane
radial - a fissure that bisects the annular layers from central to external in the sagittal or coronal plane
concentric - a fissure that extends along the orientation of the annular layers
A transverse annular tear at the discovertebral junction is depicted.
Case Discussion
Annular fissures within a disc are a common degenerative/posttraumatic finding on MRI that present as a high intensity zone (HIZ) on fluid-sensitive sequences. The term fissure is preferred over tear as these may or may not be traumatic in etiology, and upon their discovery the consideration of these lesions on imaging should be discussed as a morphologic change without implying a causal etiology 1.