J Korean Radiol Soc.  2007 Oct;57(4):385-389. 10.3348/jkrs.2007.57.4.385.

MR Imaging Findings of a Sequestered Disc in the Lumbar Spine: A Comparison with an Extruded Disc

• Sim SY
• Park JS
• Jin W
• Ryu KN

• KMID: 2103895
• DOI: http://doi.org/10.3348/jkrs.2007.57.4.385

Abstract

PURPOSE
To compare the MR findings of a sequestered disc with an extruded disc.
MATERIALS AND METHODS
MR images of 28 patients with a sequestered disc and 18 patients with an extruded disc were retrospectively reviewed. Patients with sequestered discs were divided into two groups whether definite separation from the parent disc was or was not seen. In the latter group (definite separation not seen) and the extruded disc group of patients, the signal intensities of the herniated discs were compared with the signal intensities of the parent discs and were evaluated on T1- and T2-weighted images. We also assessed the presence of a notch within the herniated disc.
RESULTS
In the sequestered disc group of patients (28 discs), only 5 discs (18%) showed obvious separation from the parent disc. Among the remaining 23 discs with indefinite separation, the notch was visible in 14 discs (61%) and 9 discs (39%) had no notch. In the extruded disc group (18 discs), the notch was visible in 2 (11%) discs and the difference between the two groups was statistically significant (p = 0.0002). The signal intensities of the herniated discs on T1-weighted images were isointense in both the sequestered and extruded discs. The difference of incidence of high signal intensities on T2-weighted images was not statistically significant (p = 0.125).
CONCLUSION
It is necessary to consider the possibility of the presence of a sequestered disc when a herniated disc material shows a notch.

Keyword

Magnetic resonance (MR); Spine, intervertebral disk

MeSH Terms

Humans
Incidence
Intervertebral Disc Displacement
Magnetic Resonance Imaging*
Parents
Retrospective Studies
Spine*