New MRI grading system for the cervical canal stenosis.

OBJECTIVE The purpose of this study was to propose a new MRI grading system for cervical canal stenosis and to evaluate the reproducibility of the system. MATERIALS AND METHODS Cervical canal stenosis was classified according to the T2-weighted sagittal images into the following grades: grade 0, absence of canal stenosis; grade 1, subarachnoid space obliteration exceeding 50%; grade 2, spinal cord deformity; and grade 3, spinal cord signal change. The MRI scans of 82 patients (37 men and 45 women; mean age, 65.2 years; range, 60-86 years) were independently analyzed by six radiologists. Interobserver and intraobserver agreements were analyzed using intraclass correlation coefficient (ICC), along with the percentage agreement and kappa statistics. RESULTS The ICC for interobserver agreement was 0.716-0.802, indicating good-to-excellent agreement. For the distinction among the four grades, the percentage of agreement was 63-64% (κ = 0.60-0.62). The percentage of agreement for the presence of cervical canal stenosis (grade 0 vs grades 1, 2, and 3) was 79-85% (κ = 0.51-0.59). The percentage of agreement for insignificant (grade 0-1) or significant (grade 2-3) stenosis was 81-85% (κ = 0.57-0.66). The percentage of agreement for the presence of spinal cord signal change (grade 0-2 vs grade 3) was 92-95% (κ = 0.70-0.73). The overall intraobserver agreement was excellent, as determined by an ICC of 0.768. CONCLUSION The new grading system provides a reliable assessment of cervical canal stenosis.

[1]  Ying Zhang,et al.  Fundamentals of Biostatistics , 2007 .

[2]  R. R. Smith,et al.  Myelopathic cervical spondylotic lesions demonstrated by magnetic resonance imaging. , 1988, Journal of neurosurgery.

[3]  E. Larsson,et al.  Comparison of Myelography, CT Myelography and Magnetic Resonance Imaging in Cervical Spondylosis and Disk Herniation , 1989, Acta radiologica.

[4]  Kazuo Yonenobu,et al.  Interobserver and Intraobserver Reliability of the Japanese Orthopaedic Association Scoring System for Evaluation of Cervical Compression Myelopathy , 2001, Spine.

[5]  Y. Yukawa,et al.  MR T2 Image Classification in Cervical Compression Myelopathy: Predictor of Surgical Outcomes , 2007, Spine.

[6]  R. Lebel,et al.  Diffusion Tensor Imaging Correlates with the Clinical Assessment of Disease Severity in Cervical Spondylotic Myelopathy and Predicts Outcome following Surgery , 2013, American Journal of Neuroradiology.

[7]  D. Kaech,et al.  Dynamic imaging of the spine with an open upright MRI: present results and future perspectives of fmri , 2007 .

[8]  H. Pavlov,et al.  Cervical spinal stenosis: determination with vertebral body ratio method. , 1987, Radiology.

[9]  H. Nagashima,et al.  Correlation Between Operative Outcomes of Cervical Compression Myelopathy and MRI of the Spinal Cord , 2001, Spine.

[10]  Michael J Lee,et al.  Prevalence of cervical spine stenosis. Anatomic study in cadavers. , 2007, The Journal of bone and joint surgery. American volume.

[11]  L. Dušek,et al.  Presymptomatic Spondylotic Cervical Cord Compression , 2004, Spine.

[12]  H. Larocca,et al.  The Developmental Segmental Sagittal Diameter of the Cervical Spinal Canal in Patients with Cervical Spondylosis , 1983, Spine.

[13]  H. Kundel,et al.  Measurement of observer agreement. , 2003, Radiology.

[14]  Wen-Bin Li,et al.  Qualitative assessment of cervical spinal stenosis: observer variability on CT and MR images. , 2003, AJNR. American journal of neuroradiology.

[15]  J. Sim,et al.  The kappa statistic in reliability studies: use, interpretation, and sample size requirements. , 2005, Physical therapy.

[16]  R. Newcombe,et al.  Are T1 weighted images helpful in MRI of cervical radiculopathy? , 2004, The British journal of radiology.

[17]  M K Markey,et al.  The reliability of measuring physical characteristics of spiculated masses on mammography. , 2006, The British journal of radiology.

[18]  A. Sharan,et al.  Cervical Myelopathy: A Clinical and Radiographic Evaluation and Correlation to Cervical Spondylotic Myelopathy , 2010, Spine.

[19]  B. Sennett,et al.  Neurapraxia of the cervical spinal cord with transient quadriplegia. , 1986, The Journal of bone and joint surgery. American volume.

[20]  A. Inoue,et al.  Clinical Value of Magnetic Resonance Imaging for Cervical Myelopathy , 1990, Spine.

[21]  Y. Yamashita,et al.  Chronic cervical cord compression: clinical significance of increased signal intensity on MR images. , 1989, Radiology.

[22]  D. Resnick,et al.  Classification system based on kinematic MR imaging in cervical spondylitic myelopathy. , 1998, AJNR. American journal of neuroradiology.

[23]  W. Börm,et al.  Degenerative cervical spinal stenosis: current strategies in diagnosis and treatment. , 2008, Deutsches Arzteblatt international.

[24]  A. White,et al.  Cervical spondylotic myelopathy. , 1993, The Journal of bone and joint surgery. American volume.

[25]  J. R. Landis,et al.  The measurement of observer agreement for categorical data. , 1977, Biometrics.

[26]  A. White,et al.  Cervical spondylotic myelopathy. , 1993, The Journal of bone and joint surgery. American volume.

[27]  R. Pietrobon,et al.  Observer agreement of spine stenosis on magnetic resonance imaging analysis of patients with cervical spine myelopathy. , 2008, Journal of manipulative and physiological therapeutics.

[28]  K. Yonenobu,et al.  Can intramedullary signal change on magnetic resonance imaging predict surgical outcome in cervical spondylotic myelopathy? , 1999, Spine.

[29]  J. Gilbert,et al.  Upright weight-bearing cervical flexion/extension dynamic magnetic resonance imaging: Case report and review of the literature , 2006 .