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. 2009 Jun;3(1):16-20.
doi: 10.4184/asj.2009.3.1.16. Epub 2009 Jun 30.

Reliability of MRI findings for Symptomatic Extraforaminal Disc Herniation in Lumbar Spine

Kyu Pill Moon  1 , Kuen Tak Suh, Jung Sub Lee
Affiliations

Reliability of MRI findings for Symptomatic Extraforaminal Disc Herniation in Lumbar Spine

Kyu Pill Moon et al. Asian Spine J. 2009 Jun.

Abstract

Study design: A retrospective study

Purpose: This study examined the reliability of the MRI findings in detecting symptomatic extraforaminal disc herniation in the lumbar spine.

Overview of literature: There are no reports of the characteristics and reliable MRI findings of extraforaminal disc herniation.

Methods: Thirty age-and gender-matched asymptomatic volunteers and 30 patients with symptomatic extraforaminal disc herniation, who underwent surgery between March 2006 and Dec 2008, were enrolled in this study. All subjects underwent spinal MRI. The following parameters were evaluated: the presence or absence of focal eccentricity of the disc, change in the diameter of the nerve root, and displacement of the nerve root at the extraforaminal zones. Radiologic studies were reviewed blindly and independently by 3 spine surgeons.

Results: The overall agreement in determining the presence or absence of a symptomatic extraforaminal disc herniation between the three reviewers was 89.4% (161/180). The consensus showed focal eccentricity of the disc in 33 cases (55%), a change in diameter in the nerve root in 31 cases (51.7%), and a displacement of the nerve root in 23 cases (38.3%). An assessment of the paired intraobserver and interobserver reliability revealed mean Kappa statistics of 0.833 and 0.667 for focal eccentricity of the disc, 0.656 and 0.556 for a change in the diameter of the nerve root, and 0.669 and 0.020 for a displacement of the nerve root, respectively.

Conclusions: There are three possible MRI findings that can be used to determine the presence or absence of symptomatic extraforaminal disc herniation. Among these MRI findings, focal eccentricity of the disc was found to be the most reliable.

Keywords: Disc herniation; Extraforaminal; Lumbar spine; Magnetic resonance imaging; Reliability.

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Figures

Fig. 1
Fig. 1
Thirty-year-old man with left extraforaminal disc herniation at the L3-4 level. Axial T1-weighted image of the disc level shows obvious focal eccentricity of the disc contour (arrow) in the left extraforaminal zone. The left exiting L3 nerve root (arrowhead) was compressed due to protruded disc material.
Fig. 2
Fig. 2
Sixty-five-year-old man with right foraminal and extraforaminal disc herniation at the L5-S1 level. Focal eccentricity or obvious asymmetry of the disc contour was indistinct on the axial T1-weighted image. The right exiting L5 nerve root (arrowhead) was compressed and displaced compared to the contralateral one (arrow).
Fig. 3
Fig. 3
Fifty-five-year-old man with right extraforaminal disc herniation at the L4-5 level. Subtle asymmetry of the disc contour (arrow) is noted on the axial T2-weighted image. The right exiting L4 nerve root (arrowhead) is swollen compared to the contralateral one.
See this image and copyright information in PMC

References

    1. Abdullah AF, Ditto EW, 3rd, Byrd EB, Williams R. Extreme-lateral lumbar disc herniations: clinical syndrome and special problems of diagnosis. J Neurosurg. 1974;41:229–234. - PubMed
    1. Baba H, Maezawa Y, Furusawa N, et al. Extraforaminal lumbar disc herniation at two contiguous intervertebral levels. Spinal Cord. 1997;35:725–728. - PubMed
    1. Grenier N, Greselle JF, Douws C, et al. MR imaging of foraminal and extraforaminal lumbar disk herniations. J Comput Assist Tomogr. 1990;14:243–249. - PubMed
    1. Wiltse LL, Spencer CW. New uses and refinements of the paraspinal approach to the lumbar spine. Spine (Phila Pa 1976) 1988;13:696–706. - PubMed
    1. Abdullah AF, Wolber PG, Warfield JR, Gunadi IK. Surgical management of extreme lateral lumbar disc herniations: review of 138 cases. Neurosurgery. 1988;22:648–653. - PubMed