Ultrasound Osteoporosis Score: A novel parameter for the estimation of spine mineral density

Aim of this work was to evaluate the effectiveness of a recently introduced ultrasound (US) parameter for the estimation of bone mineral density (BMD) of the lumbar spine, when extensively used in a clinical context to investigate adult women of variable body mass index (BMI). A total of 414 female patients (aged 51-60 years) underwent a spinal dual X-ray absorptiometry (DXA) and an abdominal echographic scan of the lumbar spine. US images and corresponding unfiltered radiofrequency signals were analyzed through a new fully automatic algorithm, which performed a series of spectral and statistical analyses to calculate the novel diagnostic parameter, called the Osteoporosis Score (O.S.). Effectiveness of O.S. in BMD estimation and subsequent osteoporosis diagnosis was assessed through a direct comparison with DXA measurements (assumed as the gold standard reference), by quantifying the agreement between the two methods through accuracy calculation and Pearson correlation coefficient (r). A very good and significant correlation was found between O.S.-estimated BMDs and corresponding DXA values over the whole considered study population (r=0.81, p<0.001). The subsequent diagnostic classifications of patients as osteoporotic, osteopenic or healthy on the basis of O.S.-estimated BMD values resulted in an overall accuracy of 90.1%. Interestingly, both the adopted metrics (r value and accuracy) were not appreciably influenced by patient BMI, demonstrating that US-measured O.S. is significantly correlated with spinal BMD in adult women independently of their BMI. Therefore, the clinical translation of this innovative method for osteoporosis diagnosis can be envisioned.