Diagnostic utility of additional spine imaging for syrinx detection in the pre-operative assessment of pediatric Chiari malformation type 1.

BACKGROUND

Chiari malformation type 1 (CM1) is sometimes associated with syringomyelia, most often in the cervical spine. Many clinicians pursue additional spine imaging to identify syrinxes; however, this imaging in pediatric CM1 patients often requires general anesthesia and endotracheal intubation, with significant risk and cost considerations.

OBJECTIVES

We aim to determine the diagnostic yield and clinical utility of additional spine imaging for syrinx detection in surgical pediatric CM1 patients.

METHODS

We retrospectively reviewed the electronic medical records and imaging of all pediatric CM1 patients who underwent surgical Chiari decompression at our institution over a 20-year period. The sensitivity and negative predictive value (NPV) of brain MRIs alone for syrinx detection and the diagnostic yield of additional spine MRIs in brain MRI syrinx-negative patients were assessed.

RESULTS

One hundred and fifty-nine CM1 pediatric patients underwent surgical Chiari decompression at our institution from 2001 to 2020. Forty-four patients had a syrinx as determined by both brain and spine MRI, but 41 (93.2%) were identifiable on brain MRI alone. Therefore, brain MRIs had a sensitivity of 93.2% and an NPV of 93.3% for syrinx detection. Spine MRIs in patients with syrinx-negative brain MRIs had a diagnostic yield of 6.7%. Thirty-five (40.7%) of the patients with both brain and spine MRI's required general anesthesia for spine MRI.

CONCLUSION

Our retrospective cohort study demonstrates clinicians should consider the high sensitivity and NPV of brain MRIs and the low diagnostic yield, cost, and anesthesia-related risks of additional spine imaging for syrinxes in pediatric CM1 patients.