Poster Presentation 50th International Society for the Study of the Lumbar Spine Annual Meeting 2024

Introduction

Younger adolescents may exhibit vertebral changes due to e.g. trauma, infection, or other specific conditions, which may affect the bone marrow in the spine. The aetiology and characteristics may differ from degenerative changes, typically associated with age (1). MRI can clearly display most spine pathologies. To improve the knowledge of how such changes evolves over time there is, however, a need for objective markers that enable longitudinal follow-up.

The aim was to characterize the vertebrae in a large cohort of asymptomatic young adolescents using normalized objective MRI-signals and compare between spine levels within the cervical, thoracal and lumbar vertebrae.

Methods

The vertebrae (C3–L5) of 69 young 14-year-old healthy adolescents with no clear signs of spine pathologies were examined on a 1.5T scanner with sagittal T1- and non-fat-supressed T2-weighted MRI. In three image slices, global T1- and T2means were determined as the T1 and T2 vertebral signal normalized to the fat signal (Figure 1). All values were compared between spine levels.

Results

Higher T1- and T2means were found in the vertebrae at the lumbar compared to the cervical/thoracal spine (p<1e-7; Figure 2;). Significant differences in T2means between cervical and thoracal spine was also found (p<0.03). The MR images at the lumbar spine revealed hyper-signalling fat adjacent to hypo-signalling basivertebral vein (Figure 3), probably contributing to the significant differences between levels.

Discussion

In this large cohort-study of young asymptomatic individuals, we found significant level-dependent differences between vertebral T1- and T2means with highest means in the lumbar spine. Even though similar MRI characteristics have been reported for older individuals (1), the included cohort displayed slightly higher means with less pronounced level-dependence, probably reflecting the lack of degenerative changes but a larger extent of hematopoietic tissue and focal fat deposit adjacent to the basivertebral in these younger adolescents (2). These finding highlights the importance of using specific normative base-line values for younger adolescents, stratified both for level differences, when following-up relevant vertebral changes in these individuals.

References

[1] Cheong HK, Choi DS, Park KU, Kim JR, Ha KI, Yun HJ, et al. Quantitative assessment of bone marrow cellularity by magnetic resonance imaging in workers with long-term exposure to solvents. Ind Health. 2004;42(2):179-88.

[2] Ricci C, Cova M, Kang YS, Yang A, Rahmouni A, Scott WW, Jr., et al. Normal age-related patterns of cellular and fatty bone marrow distribution in the axial skeleton: MR imaging study. Radiology. 1990;177(1):83-8.