Osteoporosis imaging: effects of bone preservation on MDCT-based trabecular bone microstructure parameters and finite element models

Abstract

BackgroundOsteoporosis is defined as a skeletal disorder characterized by compromised bone strength due to a reduction of bone mass and deterioration of bone microstructure predisposing an individual to an increased risk of fracture. Trabecular bone microstructure analysis and finite element models (FEM) have shown to improve the prediction of bone strength beyond bone mineral density (BMD) measurements. These computational methods have been developed and validated in specimens preserved in formalin solution or by freezing. However, little is known about the effects of preservation on trabecular bone microstructure and FEM. The purpose of this observational study was to investigate the effects of preservation on trabecular bone microstructure and FEM in human vertebrae.MethodsFour thoracic vertebrae were harvested from each of three fresh human cadavers (n = 12). Multi-detector computed tomography (MDCT) images were obtained at baseline, 3 and 6 month follow-up. In the intervals between MDCT imaging, two vertebrae from each donor were formalin-fixed and frozen, respectively. BMD, trabecular bone microstructure parameters (histomorphometry and fractal dimension), and FEM-based apparent compressive modulus (ACM) were determined in the MDCT images and validated by mechanical testing to failure of the vertebrae after 6 months.ResultsChanges of BMD, trabecular bone microstructure parameters, and FEM-based ACM in formalin-fixed and frozen vertebrae over 6 months ranged between 1.0–5.6 % and 1.3–6.1 %, respectively, and were not statistically significant (p > 0.05). BMD, trabecular bone microstructure parameters, and FEM-based ACM as assessed at baseline, 3 and 6 month follow-up correlated significantly with mechanically determined failure load (r = 0.89–0.99; p < 0.05). The correlation coefficients r were not significantly different for the two preservation methods (p > 0.05).ConclusionsFormalin fixation and freezing up to six months showed no significant effects on trabecular bone microstructure and FEM-based ACM in human vertebrae and may both be used in corresponding in-vitro experiments in the context of osteoporosis.

Effects of dose reduction on bone strength prediction using finite element analysis

“…According to several studies, BMD is only able to predict fractures with a detection rate of 30–50%1213. This implies that BMD values often underestimate fracture risk, since osteoporotic fractures frequently occur in patients with non-pathological BMD values14. Thus, it is necessary to move beyond a singular dependence on BMD since it excludes underlying information on the local bone mass distribution.…”

Reliability of 3D image analysis and influence of contrast medium administration on measurement of Hounsfield unit values of the proximal femur

“…We had previously calculated the mean HU value and HUHA proportions on coronal reformatted images of the proximal femur [ 4 ] because we thought that the coronal reformatted image of the femur would be optimal, reflecting five trabecular groups on a single slice image, and thus better than axial and sagittal images when evaluating osteoporosis. We plotted the ROI on coronal reformatted images and included the largest area of Ward’s triangle, which is known as the most important structure for evaluating the osteoporotic femur [ 22 , 15 ]. Although the ROI-based image analysis showed moderate to good reproducibility (kappa value, 0.67 to 0.86) in a previous study [ 4 ], the ROI selection itself was subjective since the process involved selection of one cross-section from several CT images, and subjective factors such as selection of the ROI location and determination of ROI size influenced the process of drawing the ROI on the selected image.…”

Russian federal clinical guidelines on the diagnostics, treatment, and prevention of osteoporosis

“…Мультиспиральная томография (МСКТ), магнитно-резонансная томография (МРТ) и сцинтиграфия скелета могут рассматриваться в качестве дополнительных методов дифференциальной диагностики [26][27][28][29].…”