Evaluation of lumbar vertebral bone quality using T1-weighted MRI: Can it differentiate normal, osteopenia, and osteoporosis?

Abstract

Background: Osteoporosis, a systemic skeletal disease characterized by low bone mass and microarchitectural deterioration, poses a significant public health challenge globally. While the gold standard for diagnosing osteoporosis is dual-energy X-ray absorptiometry (DXA), its use is limited by factors like spinal deformities and artifacts. This study aims to explore the potential of routine T1-weighted MRI sequences in predicting osteopenia and osteoporosis through the vertebral bone signal (VB) to cerebrospinal fluid signal (CSF) ratio.

Methodology: We conducted a retrospective study of patients who underwent both DXA and lumbar MRI within a six-month interval between 2020 and 2023. Excluding patients with known vertebral fractures, bone tumors, heterogeneous bone marrow, or endplate signal changes due to degenerative alterations, we divided the patients into normal, osteopenic, and osteoporotic groups based on their DXA T-scores. The T1-weighted sagittal MRI sequences were analyzed, and the T1 VB/CSF ratios were calculated for each vertebra (L1-L4).

Results: The study included 376 patients, with an average age of 60.8 ± 9.1 years. Statistically significant differences were found in the T1 VB/CSF ratios across the normal, osteopenic, and osteoporotic groups (p < 0.05). The L1 vertebra demonstrated the highest diagnostic performance for predicting osteoporosis, with an AUC of 0.75, a sensitivity of 88.1 %, and a specificity of 84.5 %. For differentiating osteopenia from normal, the L1 vertebra achieved an AUC of 0.68, with a sensitivity of 78.2 % and a specificity of 76.4 %. The optimal cut-off values were determined as 3.62 for osteopenia and 3.80 for osteoporosis.

Conclusion: The T1 VB/CSF ratio derived from routine lumbar MRI sequences provides a promising, radiation-free tool for opportunistic screening of osteoporosis and osteopenia. Given the frequent use of lumbar MRI for patients with spinal complaints, this method could facilitate early diagnosis and intervention, guiding high-risk patients towards further DXA evaluation and management.