Usefulness of Coronal MR Image in Diagnosis of Foraminal and Extraforaminal Disc Herniation / 대한척추외과학회지

ABSTRACT

STUDY DESIGN: This is a retrospective study OBJECTIVES: The coronal MR images were carefully evaluated to document the efficacy of diagnosing foraminal and extraforaminal disc herniations. SUMMARY OF LITERATURE REVIEW Extraforaminal disc herniations constitute 1~11.7% of all disc herniations. The diagnosis of it demands great caution because it must be distinguished from intraspinal canal disc herniation. Diagnosing extraforaminal disc herniations can be neglected with using ordinary diagnostic methods. MATERIALS AND METHODS: A retrospective analysis was performed on 24 patients, (26 cases) that underwent lumbar spine MRI, with the T2 coronal images, for the evaluation of disc herniations from March 2006 to March 2007. Every MRI image of each patient who had foraminal or extraforaminal disc herniations was graded according to the Pfirrmann's classification of diagnostic efficacy by two spinal surgery specialists and two radiology specialists. RESULTS: There were 13 cases of foraminal disc herniation and 13 cases of extraforaminal disc herniation in all 26 cases that were diagnosed by MRI. The coronal and axial images were more effective than the sagittal images for the discrimination of a compressed root. Especially, for the extraforaminal disc herniation, all of the coronal images were graded as grade 3; on the other hand, all of the sagittal images were not helpful for the assessment and the axial images were graded as grade 2 for 38.5% of the and as grade 3 for 61.5%. So, the coronal images were most effective for making the diagnosis of extraforaminal disc herniation and this was statistically significant (p<0.05). CONCLUSION: For the accurate discrimination of the location and the grading of foraminal and extraforaminal disc herniation, MRI, and especially the coronal images, is an effective and useful method in addition to conducting a physical examination.