Researcher(s)
- Natalie Gaeta, Biomedical Engineering, University of Delaware
Faculty Mentor(s)
- Dawn Elliot, Biomedical Enhineering, University of Delaware
Abstract
Introduction
Lower back pain is the leading cause of disability, with intervertebral disc degeneration frequently cited as a contributing factor. Magnetic resonance imaging (MRI) is often used to evaluate disc degeneration through morphometric measures. Accurate and consistent quantification of disc morphometry is essential for the interpretability and comparability of MRI-based assessments. Manual segmentation, used to quantify disc morphometry, can introduce variability depending on the rater’s experience and technique. This study investigates the inter-rater reproducibility of disc morphometric parameters to evaluate the reliability of manual segmentation in the lumbar spine.
Methods
Four asymptomatic participants (ages 20–26) underwent a standardized lumbar MRI protocol. T1-weighted FLASH sequences were used to analyze the geometry of the 5 lumbar discs, levels L1 to S1. Three raters (0.2 to 7 years of experience) manually segmented the discs using ITK-SNAP to quantify volume and mid-sagittal area. Disc width was drawn by each rater as the anterior–posterior distance, and height was calculated by dividing area by width. Inter-rater reliability was assessed using the intraclass correlation coefficient (ICC), with both overall agreement and pairwise comparisons evaluated.
Results
Results demonstrated excellent inter-rater agreement across all parameters: volume (ICC = 0.990), area (0.996), width (0.985), and height (0.985). Pairwise Volume comparisons between raters yielded ICC values of 0.999 (7 and 2 years), 0.997 (2 and 0.2 years), and 0.998 (7 and 0.2 years), confirming reproducibility in manual segmentation, regardless of experience level.
Discussion and Conclusion
This study supports the reliability of MRI-based geometric analysis for evaluating lumbar disc morphometry. The high ICC values suggest that manual segmentation is a dependable method for quantifying lumbar disc morphometry. Future work may focus on intra-rater repeatability to assess individual consistency and further refine segmentation protocols, enhancing the precision of MRI measurements in spine research.