Mobility Assessment Using Multi-Positional MRI in Children with Cranio-Vertebral Junction Anomalies

Area of Science:

• Pediatric Radiology
• Orthopedic Surgery
• Neurology

Background:

• Cranio-vertebral junction (CVJ) anomalies can lead to instability in pediatric patients.
• Accurate identification of CVJ instability is crucial for appropriate management.
• Current diagnostic methods may have limitations in assessing dynamic instability.

Purpose of the Study:

• To evaluate the utility of multi-positional MRI (mMRI) in detecting CVJ instability in pediatric patients with CVJ anomalies.
• To establish objective mMRI criteria for diagnosing CVJ instability.
• To correlate MRI findings with anatomical variations and instability.

Main Methods:

• Retrospective review of mMRI data from pediatric patients with CVJ anomalies (2017-2021).
• Morphometric analysis using hierarchical clustering on principal component analysis (HCPCA) based on occipito-cervical parameter delta (Δ) values.
• Morphological analysis using dynamic geometric CVJ models and displacement vector analysis.
• Receiver operating characteristics (ROC) curve analysis to determine instability cut-off values for key parameters.
• Qualitative anatomical analysis of the CVJ.

Main Results:

• Forty-seven pediatric patients were analyzed.
• HCPCA identified two clusters: stable (n=39) and unstable (n=8) patients.
• ΔpB-C2 ≥2.5 mm (AUC 0.98) and ΔBAI ≥3 mm (AUC 0.97) accurately predicted instability.
• Geometric analysis revealed anterior C1 subluxation in unstable patients.
• Instability correlated with C2 anomalies, including fusions with C3.

Conclusions:

• Objective mMRI criteria, including ΔpB-C2 and ΔBAI cut-off values, can reliably identify CVJ instability in pediatric patients.
• These morphometric parameters provide objective measures for diagnosing CVJ instability.
• Further validation through prospective studies is recommended.