A new ultrasonic method for lumbar spine densitometry

Aim of this work was to carry out a first clinical validation of a new ultrasound (US)-based approach to bone densitometry of lumbar spine. A total of 290 female patients were enrolled for this study (45–75 years of age, body mass index (BMI)<40 kg/m²) and all of them underwent two different diagnostic investigations: a lumbar DXA (dual-energy X-ray absorptiometry) and an US scan of the same vertebras, performed with an echographic device configured for the acquisition of both echographic images and unfiltered radiofrequency signals. US data analysis was carried out through an innovative algorithm, whose main features include: a) measurements are always performed on a specific region of interest of the vertebra, identified on the basis of both morphologic and spectral characteristics; b) analysis takes into account patient BMI; c) the algorithm is integrated with a reference database containing model acquisitions for different combinations of patient age, sex and BMI. Accuracy of final algorithm output, represented by the same diagnostic parameters of a DXA investigation, was evaluated through a direct comparison with DXA results. For 84.5% of the patients US diagnosis (osteoporotic, osteopenic, healthy) coincided with the corresponding DXA one and this accuracy level was not appreciably influenced by patient age nor by BMI. The proposed approach represents the first US method for osteoporosis diagnosis which is directly applicable on spine and has the potential to be effectively used for population mass screenings.