Opportunistic Hounsfield units measurements on computed tomography scans can predict the number of prevalent vertebral compression fractures in older adults.

Abstract

There is a growing interest in using computed tomography (CT) scans to opportunistically assess bone mineral density via Hounsfield units (HU). Previous studies have shown lower HU in patients with vertebral compression fractures (VCFs) and that HU can predict pre-existing VCFs. This study evaluated whether HU from CT scans can predict the number of prevalent VCFs. We studied 353 patients (199 females) aged 58 and older who underwent thorax-abdomen-pelvis or thoracic-lumbar CT scans. HU were measured at T11 and L1. Inter- and intra-observer agreement measuring HU was assessed. We compared mean HU values using the T-test, performed Spearman's correlation between HU and VCFs, and conducted logistic and linear regression analyses to determine the independent effect of sex, age, and HU on the presence and number of VCFs. The median age was 73 years. Ninety-eight patients had at least one VCF, with 46 having one and 52 having two or more VCFs. Inter- and intra-observer agreement assessing HU was excellent (ICC = 0.98 and 0.99 respectively). Mean HU were significantly lower in patients with VCFs (91.14 ± 39.33) than in patients without VCFs (145.03 ± 41.07, p < 0.01). HU negatively correlated with the number of VCFs (r = - 0.54, p < 0.01). Logistic regression showed that age (p < 0.01) and HU (p < 0.01) predicted the presence of VCFs. Linear regression found that HU independently predicted the number of VCFs (p < 0.01), while age (p = 0.67) and sex (p = 0.12) did not. HU from CT scans can predict the presence and number of VCFs.