Ultra-short time-to-echo magnetic resonance imaging disc sign: a novel imaging biomarker associated with spine degeneration, pain, and disability

Abstract

OBJECTIVE: Ultra-short time-to-echo (UTE) magnetic resonance imaging (MRI) assesses short T2 components. On observation, we have identified a new imaging phenotype of the intervertebral discs — the ‘UTE disc sign (UDS)’. This study assessed UDS prevalence and its association with disc degeneration and pain / disability profiles. METHODS: A total of 76 southern Chinese subjects were recruited (mean age, 50.6 years) for T2-weighted (T2W), T1rho, and UTE MRIs of the lumbar spine (380 discs). The T2W MRI was used to assess disc degeneration and other phenotypes, and T1rho MRI was implemented to obtain quantitative proteoglycan disc profiles. The UDS was detected on UTE as a hyperor hypo-intense band across a disc. Subject demographics, as well as pain and disability profiles were obtained. RESULTS: The UDS was noted in 25% of the subjects. In all, 80% UDS occurred at the lower lumbar levels. Subjects with UDS had significantly more disc degeneration as well as the occurrence of disc displacement, spondylolisthesis, and Modic changes. The T1rho values were lower in UDS discs than non-UDS discs. The majority of UDS could not be detected on T2W MRI. The number of UDS disc levels significantly correlated with worse disability scores compared with T2W MRI. Chronic low back gain was noted in individuals with multi-level UDS. CONCLUSION: This is the first study to report UDS in humans. The UDS is a novel and easily identifiable imaging biomarker highly associated with spine degeneration and a worse clinical profile. The UDS serves as a new phenotype that broadens our understanding of degenerative disc changes and may have potential clinical utility.