ASSOCIATION OF CT-ESTIMATED LUMBAR BONE MINERAL DENSITY AND FATTY INFILTRATION OF PSOAS MUSCLE IN A YOUNG AND MIDDLE AGE POPULATION

Abstract

AIMS: Age-related changes of bones and skeletal muscles were investigated in previous studies. The aim of our study was to determine the possible association of CT-estimated lumbar spine bone density and psoas major muscle changes in a young and middle-aged population, in whom the age-related changes are not considerably advanced. We also investigated to which extent the iodine contrast affects bone and muscle attenuation.

METHODS: Baseline and CT imaging data of patients aged 18 to 49 years, who underwent a multiphasic abdominopelvic CT at the University Hospital Split from July to December 2021, were retrospectively retrieved. CT attenuation values, Hounsfield Units (HU), of lumbar spine and psoas major muscle were measured at the level of L4 on native (precontrast), arterial and venous postcontrast scans.

RESULTS: The mean age of 113 included patients was 40.61 years, 51.33 % were men. CT attenuation values of lumbar spine and psoas major muscle correlated. The highest correlation was found between age and L4, while the correlation between age and psoas muscle was somewhat weaker. No significant differences were observed between the sexes, except higher L4 HU in women. The application of iodine contrast significantly increased HU, with a mean increase of nearly 12% at lumbar spine and 18-26% at psoas muscle.

CONCLUSION: CT attenuation values of lumbar spine and psoas major muscle correlate in young and middle-aged population. Age-related changes were somewhat stronger in bones than in muscles. Iodine contrast increased significantly the HU of both bone and muscle.