Assessment of Lumbar Vertebrae Morphology by Computed Tomography in Older Adults with Osteoporosis

Background: Hounsfield Units (HU) values derived from Computerized Tomography (CT) have been used in the diagnosis of osteoporosis in the lumbar spine. Objective: This study aimed to identify anatomical dimensions of lumbar vertebrae on CT images, which were different between older normal, osteopenic, and osteoporotic subjects. Methods: This prospective pilot study enrolled 79 older adults. Based on CT measurements of lumbar vertebrae in HU, participants were classified into three groups: normal (HU > 109), osteopenia (HU: 94-108), and osteoporosis (HU < 93). Altogether, 42 anatomical variables of lumbar vertebrae, L2, L3, L4, and L5, were measured in each participant by CT, including 24 parameters measurable by MRI or plain X-ray and 18 parameters measurable by MRI only. Results: Among the morphological measurements also measurable by MRI and plain X-ray, the length upper curve, 50% and 75% of L5, length upper with the cortex of L4, length center of the cortex of L3, as well as width upper curve 75% of L2, were significantly different between the three groups (p= 0.008, 0.007, 0.035, 0.036, and 0.003 respectively). Among the morphological measurements also measurable by MRI, only the width upper cortex 75% of L5 and the width lower cortex 25% of L3, were significantly different between the three groups (p= 0.031 and 0.020, respectively). Conclusion: Seven CT morphological measurements may be used as “reference standard” CT measurements for preliminarily diagnosing osteoporosis and osteopenia in older adults.