OLSIA: Open Lumbar Spine Image Analysis - A 3D Slicer Extension for Segmentation, Grading, and Intervertebral Disc Height Index with Multi-Dataset Validation
Kowlagi, N., Kemppainen, A., McSweeney, T., Saarakkala, S., Noailly, J., Williams, F. M., ... & Tiulpin, A. (2025). OLSIA: Open Lumbar Spine Image Analysis-A 3D Slicer Extension for Segmentation, Grading, and Intervertebral Disc Height Index with Multi-Dataset Validation. Spine, 10-1097.
Low back pain and lumbar spine degeneration represent major global health challenges requiring accurate imaging assessment for diagnosis and treatment planning. This study developed and validated the Open Lumbar Spine Image Analysis (OLSIA) software, a user-friendly, no-code application that automates lumbar spine segmentation, grading, and intervertebral disc height index (DHI) calculations using deep learning models trained on the Finnish NFBC1966 dataset. The retrospective and cross-sectional study evaluated OLSIA's performance across six external datasets from diverse geographical regions (Hong Kong, UK, Spain, Hungary, Netherlands, and global sources), analyzing T2-weighted MRI mid-sagittal slices of vertebral bodies (L1-S1) and intervertebral discs (L1/2-L5/S1). The software demonstrated remarkable efficiency with a 222-fold improvement in processing time compared to manual analysis, while maintaining high inter-rater reliability (mean Dice similarity coefficient >90%) and minimal systematic bias in DHI measurements (mean difference of 0.02), making it a valuable tool for researchers from diverse backgrounds to accelerate radiomics and lumbar spine image analysis workflows without requiring coding expertise.