Dispersal Pattern of Injectate After Cervical Epidural Steroid Injection Evaluated With Magnetic Resonance Imaging

STUDY DESIGN: Prospective, nonrandomized, clinical study. OBJECTIVE: Epidural steroid injections (ESIs) are an important diagnostic and treatment modality for spine pathology. The success of these injections has been attributed to the anatomic location reached by the injectate. This study evaluates injectate dispersal patterns after cervical interlaminar ESI using magnetic resonance imaging (MRI). METHODS: Patients between the ages of 18 and 85 years with cervical radiculopathy were identified. After obtaining consent for study participation, a gadolinium-enhanced cervical ESI was administered via an interlaminar approach under fluoroscopic guidance. Study participants underwent a cervical spine MRI within 15 minutes of administering the injection. Craniocaudal dispersal and the presence or absence of circumferential dispersal was assessed. RESULTS: The injectate dispersed a mean of 8.11 cm in the cranial direction, 6.63 cm in the caudal direction, and 360° circumferentially. No adverse events related to the ESI were reported. CONCLUSIONS: Fluoroscopy-guided cervical interlaminar ESI resulted in nearly uniform circumferential dispersal within the epidural space with multilevel migration in the cranial and caudal directions. MRI is a safe and accurate tool to evaluate spinal injectate dispersal.