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%.
Keywords: Cervical vertebra; Extraforaminal ligament; MR 3D-FIESTA sequence; Transforaminal ligament.