Age-related changes to the craniocervical ligaments in asymptomatic subjects: a prospective MR study

Demonstration of transverse ligament on 3D SPACE MRI in whiplash-associated disorder and nontraumatic conditions

PURPOSE

This study aims to delineate the three-dimensional (3D) SPACE MRI findings of the transverse ligament (TL) in whiplash-associated disorder (WAD) patients, and to compare them with those from a nontraumatic group.

METHODS

A retrospective analysis was performed on cervical spine MRI scans obtained from 46 patients with WAD and 62 nontraumatic individuals. Clinical features, including the WAD grade and stage, were recorded. The TL's morphological grade and the symmetricity of the lateral atlantodental interval was assessed using axial 3D T2-SPACE images. The morphological grading was evaluated using a four-point scale: 0 = homogeneously low signal intensity with normal thickness, 1 = high signal intensity with normal thickness, 2 = reduced thickness, 3 = full-thickness rupture or indistinguishable from surrounding structures. Additionally, the number of cervical levels exhibiting degeneration was documented.

RESULTS

When comparing the WAD and nontraumatic groups, a significant difference was observed in the proportion of high-grade TL changes (grade 2 or 3) and the number of degenerated cervical levels. Logistic regression analysis revealed that high-grade TL changes and a lower number of degenerative levels independently predicted the presence of WAD. Within the WAD group, the subset of patients with high-grade TL changes demonstrated a significantly higher mean age than the low-grade group (grade 0 or 1).

CONCLUSION

High-grade morphological changes in the TL can be detected in patients with WAD through the use of 3D SPACE sequences. Clinical relevance statement 3D SPACE MRI could serve as an instrumental tool in the assessment of TL among patients with WAD. Integrating MRI findings with patient history and symptomology could facilitate the identification of potential ligament damage, and may help treatment and follow-up planning.

Imaging in Whiplash-Associated Disorders

"Whiplash," a term describing the severe acceleration and deceleration forces applied to the head, craniocervical junction (CCJ), and cervical spine during trauma, is one of the most frequent mechanisms of injury to the CCJ. The CCJ is a complex region at the transition of the cranium and the cervical spine, essential for maintaining craniocervical stability. In whiplash injuries, the CCJ may be compromised due to underlying ligamentous or, less frequently, osseous, intravertebral disk and/or muscular lesions. Imaging is crucial in detecting acute lesions but may also play a role in the follow-up of chronic pathology because soft tissue lesions and progressive disk pathology could contribute to a whiplash-associated disorder.

Comparison between 2D TSE and 3D SPACE in the evaluation of craniocervical ligaments

PURPOSE

To evaluate the MRI findings of the craniocervical junction ligaments and compare the 2D TSE sequence and 3D SPACE sequence on cervical spine MRI.

METHODS

Eighty cervical spine MRIs were retrospectively analyzed, including 2D TSE and 3D SPACE sequences. The visibility and morphology of the transverse ligament (TL) and alar ligament (AL) were evaluated by two readers using a five-point grading scale for visibility (1 = not visible, 2 = barely visible, 3 = adequately visible, 4 = good visibility, 5 = excellent visibility) and a four-point grading scale for morphology (0 = homogeneous low SI with normal thickness, 1 = high SI with normal thickness, 2 = reduced thickness, 3 = full-thickness rupture or indistinguishable from surrounding structures). The grades of the two sequences were compared. Reader agreements were measured using the percentage of exact agreement.

RESULT

The visibility grade of TL was significantly higher in 3D, indicating better visualization. The morphology grade of TL was significantly lower in the 3D, indicating more normal-appearing ligament. The exact agreements of visibility and morphology grade of TL tended to be higher in 3D. On the other hand, there was no significant difference in visibility grade of AL between the two sequences. The morphological grade of AL was significantly higher in 3D. The agreement of the morphological grade of AL tended to be lower in 3D.

CONCLUSION

The utilization of 3D sequences significantly improves the visibility of TL and could potentially reduce false-positive diagnoses of ligament injury.

Extracranial prevertebral venous network of the craniocervical junction: CT-digital subtraction venography analysis

PURPOSE

Although the craniocervical junction has a complex anatomical structure associated with clinical diseases, its ventral venous network has not been well studied. This study aimed to clarify the extracranial ventral venous structure at the craniocervical junction.

METHODS

Head computed tomography digital subtraction venography (CT-DSV) images of 273 patients (age 6 months to 93 years) taken at our department were retrospectively analyzed. We analyzed the frequency and anatomical features of the venous channels, as well as their upstream and downstream connections with the surrounding channels at the ventral craniocervical junction, from the level of the hypoglossal canal to the second cervical vertebra.

RESULTS

In 54% of the cases, the vein descended from the anterior condylar confluence, running medially along the basioccipital and fusing with its counterpart in the midline at the level of the atlanto-occipital membrane. Furthermore, 24% of this vein was connected caudally to the anterior external vertebral venous plexus. We also identified venous channels, either as a sole vein or venous plexus, on the tip of the odontoid process (10%), which has not been well described previously. The vein around the odontoid process was connected to several veins, including the aforementioned vein anterior to the condyle and the anterior internal vertebral venous plexus.

CONCLUSIONS

CT-DSV analysis revealed a detailed venous architecture ventral to the craniocervical junction. Venous structures identified in this study may be involved in diseases in this area.