676 Anatomic Assessment of L1-S1 Neural Foraminal Dimensions Using Computed Tomography

Abstract

INTRODUCTION: While radiographic parameters for diagnosis of central lumbar canal stenosis are well known, parameters for diagnosis of neural foraminal stenosis are less well defined. Previous research has used magnetic resonance imaging (MRI) to describe neural foraminal dimensions. However, the blooming artifact on MRI may distort these measurements. There is limited research using computed tomography (CT) to investigate normal neuroforamina dimensions. METHODS: We evaluated CT imaging of 55 female and 55 male subjects between 18 and 35 years of age. Those with history of degenerative disc disease, spondylolisthesis, fracture, neoplasm, trauma, existing spinal hardware, CT imaging performed due to back pain, or previous spinal surgery were excluded from review. Three independent reviewers were trained by a board-certified neuroradiologist to measure L1-S1 neural foraminal dimensions bilaterally. Intraclass correlation coefficient (ICC) two-way mixed model on absolute agreement was used to analyze interrater reliability. Pearson’s correlation was used to evaluate associations among variables. Differences between sexes were analyzed using independent sample t-tests. Measurement differences between disc levels and left- and right-sided measurements were analyzed using paired sample t-tests and one-way analysis of variance. RESULTS: Mean subject age, height, weight, and BMI were 27.16 years, 1.71 m, 88.1 kg, and 29.63 kg/m2, respectively. No moderate or strong correlations were found between measurements and age, height, weight, or BMI for all levels L1-S1. No sex differences were found for measurements at all levels L1-S1. CONCLUSIONS: This study describes CT-based L1-S1 neural foraminal dimensions in patients without pathology affecting the neuroforamina. Dimensions were not strongly influenced by demographic or anthropometric factors.