RESUMEN
<p><b>OBJECTIVE</b>To study the degree and changes of cervical spinal canal stenosis by MRI scans in flexion and extension of the cervical vertebrae.</p><p><b>METHODS</b>Thirty cases of cervical stenosis included 13 male and 17 female with an average age of 39 years ranging from 28 to 66 years. The sagittal diameter of cervical spinal canal were below 10 mm (absolute stenosis) in 12 cases,within 10 to 12 mm (correspondence stenosis) in 18 cases. MRI scans in neutrality, flexion, extension performanced and the degree of cervical spinal canal stenosis and the changes of spinal cord compression were evaluated after MRI scans obtained.</p><p><b>RESULTS</b>Nineteen patients of extension occurrenced stenosis more serious, 8 patients of flexion occurrenced (P < 0.05).</p><p><b>CONCLUSION</b>For the cervical stenosis imaging diagnostic, flexion and extension of cervical MRI scan can be used to supplement conventional MRI examination neutral position, and the extension of MRI is more sensitivity than neutral position and flexion bit.</p>