Static and dynamic cervical MRI: two useful exams in cervical myelopathy.

BACKGROUND Cervical magnetic resonance imaging (MRI) is the gold standard exam in the assessment of patients affected by cervical myelopathy and is very useful in planning the operation. Herein we present a series of patients affected by long tract symptoms who underwent dynamic MRI in addition to the static exam. METHODS In the period between March 2010 and March 2012, three-hundred-ten patients referred to our department since affected by neck/arm pain or symptoms related to cervical myelopathy. Thirty-eight patients complained "long-tract symptoms" related to cervical myelopathy. This series of patients was enrolled in the study. All patients underwent clinical and neurological exam. In all the cases, a static and dynamic cervical MRI was executed using a 3.0-T superconducting MR unit (Intera, Philips, Eindhoven, Netherlands). The dynamic exam was performed with as much neck flexion and extension the patient could achieve alone. On T2-weigthed MRI each level was assessed independently by two neuroradiologists and Muhle scale was applied. RESULTS According to Muhle's classification of spinal cord compressions, static MRI demonstrated 156 findings: 96 (61.54%) anterior and 60 (38.46%) posterior. Dynamic MRI showed 186 spinal cord compressions: 81 (43.5%) anterior and 105 (56.5%) posterior. The anterior compressions were: grade 1 in 23 cases (28.4%), grade 2 in 52 cases (64.2%), grade 3 in 6 cases (7.4%). The posterior compressions were: 32 (30.48%) of grade 1, 60 (57.14%) of grade 2, 13 (12.38%) of grade 3. CONCLUSIONS The dynamic MRI demonstrated a major number of findings and spinal cord compressions compared to the static exam. Finally, we consider the dynamic exam able to provide useful information in these patients, but we suggest a careful evaluation of the findings in the extension exam since they are probably over-expressed.