Oblique Coronal MRI in the Evaluation of Bony Stenosis of the Cervical Foramina: Objectiveness and Correlation with Radiograph

PURPOSE: To determine the utility of oblique coronal MR (OMR) imaging in the evaluation of bony foraminal narrowing of the cervical spine by comparison of its findings with those of combined axial and sagittal MR (CMR) imaging and correlation with the findings of oblique radiography. MATERIALS AND METHODS: One hundred and eight cervical neural foramina in 18 patients formed the basis of this study. Three radiologists working in a blind fashion independently graded the degree of bony narrowing of the foramina seen on OMR and CMR images and on oblique radiographs (0=none, 1=stenosis below 25% of AP dimension, 2=stenosis exceeding 25% of AP dimension). Inter-observer variance was measured for each modality, and for each of these and for each foramen, consensus was reached as to whether of CMR or OMR showed better correlation with radiographs. RESULTS: Inter-observer variance in OMR was less (kappa=0.88) than in CMR (kappa=0.41). Correlation between the findings of OMR and radiography was also better (kappa=0.63) than between those of CMR and radiography (kappa=0.41). CONCLUSION: OMR can be a useful supplement in evaluating foraminal stenosis, especially when oblique radiographs and CMR images show discrepancies.