A controlled study on the anatomy of cervical extraforaminal ligaments and three-dimensional fast-imaging employing a steady-state acquisition sequence.

ABSTRACT

PURPOSE: To evaluate the utility of magnetic resonance three-dimensional fast-imaging employing a steady-state acquisition (MR 3D-FIESTA) sequence to study cervical EFLs using the anatomical results of cadavers as the gold standard. METHODS: Part I The cervical regions of five embalmed adult cadavers were scanned using the MR 3D-FIESTA sequence. Ligamentous structures in the intervertebral foramina (IVFs) between C4 and T1 in the MRI scans were identified by a radiologist. Part II After the specimens were scanned, gross and microscopic anatomical studies were conducted on the IVFs between C4 and T1 in the specimens by an anatomist. Part III Using the anatomical results of the cadavers as the gold standard, the utility of the MR 3D-FIESTA sequence for imaging cervical EFLs was evaluated. Specificity, sensitivity, positive and negative predictive values (PPV and NPV, respectively) and accuracy were calculated. RESULTS: The occurrence rate of transforaminal ligaments (TFLs) in the IVFs between C4 and T1 was 42.5%. The results obtained by the radiologist using the MR 3D-FIESTA sequence to identify TFLs are as follows specificity 96.2%, sensitivity 76.5%, PPV 92.9%, NPV 86.2%, and accuracy 88.4%. CONCLUSION: MR 3D-FIESTA sequences clearly showed cervical EFLs. In the 3D-FIESTA sequence scans that the radiologist believed to indicate the presence of a cervical TFL, the probability that the TFL existed was approximately 93%. When the radiologist believed that no TFL was present in the 3D-FIESTA sequence scan, the probability that a TFL existed was 14%.