From the Guidelines
For evaluating vertebral artery course prior to PRP injections for craniocervical instability, I recommend ordering an MRA of the head and neck with IV contrast, as it allows for better evaluation of the vessels with increased spatial resolution and decreased flow-related artifacts, as suggested by the most recent study 1.
Key Considerations
- The imaging protocol should specifically include the entire cervical spine with particular attention to the upper cervical region (C1-C2) where anatomical variations are most relevant for the procedure.
- The use of IV contrast in MRA of the neck is preferred for better evaluation of the vessels, as stated in the study 1.
- Request that the radiologist provide detailed reporting on vertebral artery course, any loops or anomalies, proximity to intended injection sites, and potential risk zones.
Rationale
- Understanding the precise vascular anatomy is essential before performing PRP injections in this region because the vertebral arteries have variable courses, particularly as they traverse the transverse foramina and around the C1-C2 articulation.
- Anatomical variants such as loops, medial deviations, or asymmetries are common and could place the artery at risk during needle placement, highlighting the importance of accurate imaging, as noted in the study 1.
- The study 1 also mentions that MRA has high sensitivity, specificity, and accuracy in evaluating vertebral artery origin stenosis, making it a reliable choice for this purpose.
Additional Points
- While other studies 2, 3, 4 provide information on various imaging modalities and their appropriateness for different scenarios, the most recent and relevant study for this specific question is 1, which guides the recommendation for using MRA with IV contrast.
- It is crucial to prioritize the safety of the patient and the success of the procedure by ensuring that the imaging provides the necessary detail to avoid vascular complications, as implied by the importance of accurate vascular anatomy understanding in the context of PRP injections for craniocervical instability.
From the Research
Evaluation of Vertebral Artery Course
To evaluate the vertebral artery course prior to Platelet-Rich Plasma (PRP) injections for craniocervical instability, the following types of Magnetic Resonance Angiography (MRA) can be considered:
- 3D time-of-flight MRA of the head and neck, as recommended for children with suspected craniocervical arterial dissection 5
- Contrast-enhanced MRA, which can be highly considered in neck imaging 5
Imaging Modalities
Other imaging modalities that can be used to evaluate the vertebral artery course include:
- CT angiography (CTA), which has been shown to be useful in demonstrating the vertebral arteries in relation to the cervical spine and associated pathology 6
- Digital subtraction angiography, which can be used to analyze the course, curvature, and termination of the vertebral artery 7
- 3D CT angiography, which can be used to investigate the prevalence of vertebral artery variations and osseous anomalies in the region of the craniocervical junction 8
Importance of Preoperative Imaging
Preoperative imaging of the vertebral artery is important to avoid injury during surgery, as highlighted in several studies:
- A study on the use of CT angiography in preoperative planning of cervical spine surgery in children found that the vertebral artery was potentially vulnerable during surgery 6
- A study on vertebral artery injury during routine posterior cervical exposure emphasized the importance of preoperative planning to identify the course of the bilateral vertebral arteries 9
- A study on craniocervical arterial dissection in children recommended MRI with MRA as the first-line imaging study, and highlighted the importance of considering the risks associated with imaging techniques 5