A new ultrasound parameter for osteoporosis diagnosis: Clinical validation on normal- and under-weight women

Aim of this work was to evaluate the effectiveness of a recently introduced ultrasound (US) method for osteoporosis diagnosis, when extensively used in a clinical context to investigate adult women of variable age. A total of 384 female patients (46-65 years; body mass index <; 25 kg/m²) underwent a spinal dual X-ray absorptiometry (DXA) and an abdominal US scan of lumbar spine, acquiring both echographic images and unprocessed radiofrequency signals. US data were analyzed through a new fully automatic algorithm, which performed a series of spectral and statistical analyses to calculate the parameter called Osteoporosis Score (O.S.). Diagnostic effectiveness of O.S. was assessed through a direct comparison with DXA measurements (assumed as the gold standard reference), quantifying the agreement between the two methods through accuracy calculation, Cohen´s kappa (k) and Pearson correlation coefficient (r). The overall accuracy of O.S.-based diagnoses resulted 84.6%, ranging from a minimum of 81.7% for the oldest patients (aged in 61-65 y) to a maximum of 87.2% for the youngest patients (aged in 46-50 y). Cohen´s kappa showed an analogous trend, confirming a significant agreement between DXA and US-based diagnoses along the whole considered age interval (k=0.758, p<;0.0001). A good correlation was also found between O.S.-derived BMD values and corresponding DXA measurements (r=0.72, p<;0.001). These results demonstrated that US-measured O.S. is significantly correlated with spinal BMD in normal- and under-weight adult women belonging to a wide age interval. Therefore, the routine clinical application of this innovative approach to osteoporosis diagnosis can be envisioned.