Magnetic resonance-based vertebral morphometry of the thoracic spine: age,gender and level-specific influences

Objective. The aim of this study was to examine age, gender, and segmental trends in thoracic vertebral body shape, utilising thoracic spine magnetic resonance images involving an age range spanning the life span. Design. A quantitative, cross-sectional, retrospective study design involvi ng a sample of convenience. Background. Thoracic vertebral shape data are commonly derived from radiogr aphic resources. The non-ionising properties of magnetic resonance imaging and availability of digital data for image analysis suggest potential for M R-based morphometric studies. For the thoracic spine, there is limited vert ebral shape data on males, while few studies have examined the pattern of a ge-related changes across the life span. Methods. Morphometry was performed on 220 mid sagittal T1-weighted MR image s using image analysis software. Three indices of vertebral shape were util ised: the antero-posterior height ratio or anterior wedge index, mid-poster ior height ratio or biconcavity index, and ratio of posterior vertebral hei ght to mid antero-posterior diameter or compression index. Results. Different segmental patterns were noted for the vertebral shape in dices. Significantly lower mean values were noted in males for the compress ion index. Age trends were significant, with a linear age-related decline d emonstrated for the anterior wedge and biconcavity indices, and a quadratic trend noted for the compression index. Conclusions. Thoracic vertebral body shape may be uniquely described using specific shape indices, for examining various segmental, gender and age-ass ociated changes. Relevance These results suggest the importance of defining specific reference criteri a for thoracic vertebral body shape indices, particularly age-related data encompassing a wide age range. Magnetic resonance studies enable interpreta tion of vertebral shape data in relation to the wide spectrum of pathologie s afflicting the thoracic spine, without the concerns of ionising radiation . (C) 2000 Elsevier Science Ltd. All rights reserved.