DeVa (Decay Variance): A Novel Score Calculated via Postprocessing the Changes in Signal Intensity of an Intervertebral Disc in a T2* Multi-Echo Magnetic Resonance Image Can Quantify Painful and Degenerate Lumbar Vertebral Discs

Introduction

Low back pain (LBP), a global disability leader, is often linked to intervertebral disc (IVD) degeneration. Traditional diagnostics like T2-weighted MRI provide qualitative but imprecise evaluations. A novel post-processing MRI technique, Decay Variance (DeVa), has shown promise in differentiating degenerate from healthy discs in animal studies. DeVa quantifies IVD degeneration by analyzing variations in signal intensities within each voxel in a T2* 2D FLASH multi-echo MRI sequence. This study aimed to validate DeVa clinically and explore its correlation with pain severity.

Methods

A cross-sectional study included 77 chronic LBP patients and 8 controls, who underwent T2-weighted and T2* 2D FLASH MRI. DeVa scores (worst and sum of all discs) were recorded, alongside traditional assessments like disc bulge, stenosis, high-intensity zones, and Pfirrmann grade. Pain severity was measured with a numerical rating scale. Statistical analyses included Pearson correlation, t-tests, and Gardner-Altman plots to evaluate relationships between DeVa scores, degeneration, and pain.

Results

DeVa scores correlated strongly with Pfirrmann grade (r = 0.692, p < 0.001) and were significantly higher in discs with bulge, stenosis, or high-intensity zones (p < 0.001). Moderate correlations were observed between worst DeVa scores (r = 0.296, p < 0.01), total DeVa scores (r = 0.323, p < 0.005) and pain severity. Patients with chronic LBP without severe degeneration (Pfirrmann ≤ 3 with no stenosis observable on standard MRI) had significantly higher worst (1.38 ± 0.26 vs. 1.10 ± 0.29, p < 0.005) and total (5.39 ± 0.75 vs. 4.65 ± 0.61, p < 0.0.1) DeVa scores compared to controls.

Discussion

DeVa offers a quantitative, noninvasive approach to assessing IVD degeneration, showing strong correlations with disc health and pain. It demonstrates enhanced sensitivity over traditional MRI, enabling the identification of pain-generating discs and informing personalized treatment strategies for chronic LBP. Further validation in larger populations is needed.