Radiofrequency Multi Echographic Spectrometry (REMS) Technology in Patients With Bone Artifacts

Introduction: Dual-energy X-ray Absorptiometry (DXA) is considered the gold standard examination for the evaluation of bone mineral density (BMD). However, it is known that some conditions, such as arthrosis, vertebral collapse, or vertebroplasty, result in an overestimation of the BMD measured by DXA. Conversely, Radiofrequency Echographic Multi-Spectrometry (REMS) technology is able to automatically discard signals related to bone artifacts, such as calcifications or osteophytes, thanks to the identification of unexpected spectral features (Diez-Perez et al. 2019). The aim of this work is to assess the performance of REMS technology in patients with bone alterations that could alter the densitometric examination. Materials: The bone densitometry exams, both REMS and DXA, of patients with evidences of bone alterations at lumbar vertebrae or femoral neck were analysed. Written patient informed consent was obtained before the scans. Results: Eighty-seven patients with spinal artifacts, including 22 patients with vertebroplasty, 26 patients with bone fracture and 38 patients with osteo-arthrosis were considered. At lumbar spine, the mean BMD and T-score values assessed by REMS was lower than the ones measured by DXA. Moreover, the results obtained by the two technologies were not correlated. On the contrary, the BMD and T-score values measured by REMS and DXA at the femoral site were highly correlated (p<0.01), as well as BMD and the T-score values measured by DXA at the femoral neck and by REMS at the lumbar spine (p<0.01). As concerning artifacts involving femoral site, a patient with an intramedullary gamma nail positioned following a displaced pertrochanteric fracture of the left femur underwent a DXA scan of the right femur and a REMS scan of both femurs. A diagnosis of osteoporosis at the right femur was posed by both technologies. At the left femur with intramedullary gamma nail, REMS only made a diagnosis of osteoporosis highly corresponding with the one performed at right femur. Conclusions: The results from the patient series with spinal artifacts and the clinical case with femoral intramedullary gamma nail show the ability of REMS to evaluate anatomical sites that would not be assessable by DXA, such as in case of implanted nails, or that would give unreliable higher BMD values, such as in case of vertebroplasty, osteo-arthrosis and bone fracture. References: Diez-Perez et al. Aging Clin Exp Res 2019;31(10):1375–89