Bone mineral density assessment using the EOS® low-dose X-ray device: A feasibility study

Abstract

To predict bone strength in the case of osteoporosis, it could be a real benefit to assess the three-dimensional (3D) geometry and the bone mineral density (BMD) with a single low-dose X-ray device, such as the EOS system (Biospace Med, Paris, France). EOS 3D reconstructions of the spine have already been validated. Thus, this study aims at evaluating the accuracy of this low-dose system as a densitometer first ex vivo. The European Spine Phantom (ESP) (number 129) was scanned ten times using both the EOS and a Hologic device (Hologic, Inc., Massachusetts, USA). Accuracy was given by the sum of the systematic error (difference between BMDs assessed and true values given by the phantom manufacturer) and the random error (coefficient of variation). EOS BMDs and Hologic BMDs of 41 ex-vivo vertebrae were calculated and compared. The reproducibility of the method evaluating the EOS BMD was assessed giving the coefficient of variation of three measurements of the 41 vertebrae. The accuracy of the EOS system is below 5.2 per cent, versus 7.2 per cent for the Hologic system in the same conditions. EOS BMDs are significantly higher than Hologic BMDs, but they are strongly correlated. The reproducibility of the method of assessment is equal to 0.95 per cent. The EOS system is accurate for ex-vivo BMD assessments, which is promising regarding the use of this new system to predict vertebral strength.

Vertebral strength prediction from Bi-Planar dual energy x-ray absorptiometry under anterior compressive force using a finite element model: An in vitro study

“…Two levels of energy can be achieved with the EOS® prototype by quickly changing the X-ray tube settings between two fast passes scans (approximately 20 s depending on the size of the lumbar spine). The computed projected areal Bone Mineral Density (aBMD) images of the vertebrae are similar to DXA images (Sapin et al, 2008;Sapin-De Brosses et al, 2012). aBMD measurement was previously validated by comparing EOS® accuracy and reproducibility with the dual x-ray absorptiometry densitometers' characteristics (Sapin et al, 2008).…”

EOS® biplanar X-ray imaging: Concept, developments, benefits, and limitations

“…EOS ® imaging was also tested for the study of vertebral osteoporosis. It was first compared to dual-energy X-ray absorptiometry (DXA) using a Hologic ® device for measurement of bone mineral density (BMD) [ 35 ]. Both techniques were used to determine BMD on the European Spine Phantom, and the results were compared to the values given by the manufacturer of the phantom.…”

“…Both techniques were used to determine BMD on the European Spine Phantom, and the results were compared to the values given by the manufacturer of the phantom. EOS ® imaging was more accurate than Hologic ® (5.2 % compared to 7.2 %) and had very good reproducibility [ 35 ]. In another study, it was used to determine the BMDs of 14 fresh-frozen vertebrae, as well as to provide a 3D reconstruction of these vertebrae [ 36 ].…”

Subject-specific mechanical properties of vertebral cancellous bone assessed using a low-dose X-ray device

“…Hence, areal bone mineral densities were assessed for the whole vertebra in both antero-posterior and lateral planes. For this first evaluation, vertebrae were scanned in the air, following the protocol previously validated [16]. Researches are in progress to quantify the effect of soft tissues on BMD assessment with the EOS ® system.…”

“…Especially, the 3D reconstruction of the spine using the EOS ® system has already been validated [13,14]; • thanks to the standing position, the EOS ® system could also evaluate the boundary conditions applied to vertebrae [15]; • in vitro areal BMD can be assessed using a dual-energy modality, with the same global error as the clinical "gold standard" dual X-ray absorptiometry (DXA) devices [16].…”