Validity of Bone Mineral Density Measurements Using SONIALVISION G4: A Quantitative CT-based Evaluation

Abstract Introduction SONIALVISION G4 is a fluoroscopic imaging system equipped with a bone densitometry function calibrated against GE Healthcare dual-energy X-ray absorptiometry (DXA) measurements. However, evidence supporting the validity of in vivo bone mineral density (BMD) measurements remains limited. This study compared BMD measurements obtained using SONIALVISION G4 with GE DXA reference data and evaluated their validity using quantitative computed tomography (CT). Materials and Methods A total of 887 BMD examinations performed with SONIALVISION G4 in women aged ≥45 years were compared with published Japanese reference data obtained using GE DXA. CT-derived BMD was quantified using a validated deep learning–based method and compared with measurements obtained using SONIALVISION G4 in 30 patients. To validate the CT method against GE DXA, 697 patients from four additional institutions underwent GE DXA and CT. Analyses were conducted for both the femoral neck and total hip. Results Femoral neck BMD generally showed small differences from the reference values, whereas total hip BMD was consistently higher in women aged ≥55 years. CT-derived BMD correlated with SONIALVISION G4 measurements (r = 0.762 and 0.842 for the femoral neck and total hip, respectively), with median absolute differences of 0.022 and 0.133 g/cm 2 . In contrast, CT-derived BMD showed very strong correlations with GE DXA (r = 0.913 and 0.959) and smaller absolute differences (0.043 and 0.033 g/cm 2 ). Conclusion SONIALVISION G4 showed small differences in femoral neck BMD measurements compared with CT-derived measurements but may systematically overestimate total hip BMD. Further validation studies are warranted.