PurposeTo determine age-related diffusivity changes of the lumbar bone marrow by measurement of apparent diffusion coefficient (ADC) values. Materials and methodsThe local ethics committee approved this study and written informed consent was obtained. The study group comprised 88 individuals including 75 healthy volunteers and 13 patients (48 female, 40 male; mean age 36 years, range 0–84 years). The pediatric cases were recruited from patients. Echo-planar diffusion weighted imaging (DWI) was performed with b-values of 50, 400 and 800s/mm2. ADC-values were calculated and measured in the 1st and 2nd vertebral body of the lumbar spine. Correlation between age and ADC-values was analyzed with Spearman's rho test. ResultsThe ADC values of the vertebral bone marrow of the lumbar spine showed a significant negative correlation with age (rho=−0.398, p=0.001). The mean ADC values (×10−3mm2/s) in the age groups 0–29 years (mean age 18.0 years, n=42) and 30–88 years (mean age 51.6 years, n=46) were 0.54±0.07 and 0.47±0.08, respectively (p<0.001, T-test). No significant differences were found between children and young adults. ConclusionBone marrow ADC values of the lumbar spine show a linear decrease with growing age and thereby reflect the gradual changes of cell composition occurring during marrow conversion.
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