Dataset Information

Comparative measurements of bone mineral density and bone contrast values in canine femora using dual-energy X-ray absorptiometry and conventional digital radiography.

ABSTRACT:

Background

Aseptic loosening due to bone remodelling processes after total hip replacement is one common cause for revision surgery. In human medicine, dual-energy X-ray absorptiometry (DEXA) is the gold standard for quantitative evaluation of bone mineral density, whereas in veterinary medicine conventional radiography is used for follow-up studies. Recently, a method has been described using digital X-ray images for quantitative assessment of grey scale values of bone contrast. Therefore, the aim of the present study was to evaluate the correlation of bone mineral density (BMD) measured by DEXA with grey scale values (GV) measured in digital X-ray images (RX50, RX66) ex vivo.

Results

The measured GV in the chosen X-ray settings showed on average a good correlation (r?=?0.61) to the measured BMD with DEXA. Correlation between the two X-ray settings was very good (r?=?0.81). For comparisons among regions of interests (ROIs) a difference of 8.2% was found to be statistically significant, whereas in the case of RX50 and RX66 differences of 5.3% and 4.1% were found to be statistically significant.

Conclusions

Results indicate that measuring absolute changes in bone mineral density might be possible using digital radiography. Not all significant differences between ROIs detectable with DEXA can be displayed in the X-ray images because of the lower sensitivity of the radiographs. However, direct comparison of grey scale values of the periprosthetic femur in one individual patient during the follow-up period, in order to predict bone remodelling processes, should be possible, but with a lesser sensitivity than with DEXA. It is important that the same X-ray settings are chosen for each patient for follow-up studies.

SUBMITTER: Lucas K

PROVIDER: S-EPMC5426025 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature

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Publications

Comparative measurements of bone mineral density and bone contrast values in canine femora using dual-energy X-ray absorptiometry and conventional digital radiography.

Lucas K K Nolte I I Galindo-Zamora V V Lerch M M Stukenborg-Colsman C C Behrens B A BA Bouguecha A A Betancur S S Almohallami A A Wefstaedt P P

BMC veterinary research 20170511 1

<h4>Background</h4>Aseptic loosening due to bone remodelling processes after total hip replacement is one common cause for revision surgery. In human medicine, dual-energy X-ray absorptiometry (DEXA) is the gold standard for quantitative evaluation of bone mineral density, whereas in veterinary medicine conventional radiography is used for follow-up studies. Recently, a method has been described using digital X-ray images for quantitative assessment of grey scale values of bone contrast. Therefo ...[more]

PMID: 28490330

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Project description:BackgroundFor bone health assessment, dual-energy X-ray absorptiometry (DEXA) is recommended to measure bone mineral content and areal bone mineral density (aBMD) in the lumbar spine. However, intermachine differences were not taken into account when developing these recommendations. According to the International Society of Clinical Densitometry (ISCD), phantom-based cross-calibration is adequate after replacing the DEXA system from a different manufacturer. For different DEXA equipment, individual calibration equations were found to be necessary to fit the observed values with the given densities.MethodsThe BMD European Spine Phantom (ESP) measurements (L1, L2, and L3) were assessed on 3 machines. We used the Welch test in the one-way analysis of variance (ANOVA) with a post-hoc Tamhane T2 test, linear regressions, and Bland-Altman analysis to assess the consistency of measurements and establish cross-calibration equations.ResultsThe coefficients of variation (CV)% of the phantom BMD values measured using the 3 systems were less than 3.0%. The 3 DEXA systems were highly correlated with BMD in the lumbar spine, with correlation values ranging from 0.933 to 0.984 (P<0.0001). The cross-calibration regression models of the ESP measurements yielded the highest prediction accuracies with the lowest prediction errors (the standard error of the estimate ranged from 0.004 to 0.008 g/cm2; P<0.0001). After the regression equations were applied, the differences in BMD values among the 3 systems were negligible. In addition, the Bland-Altman plot showed that almost all data points were within the 95% limits of agreement.ConclusionsA strong agreement for BMD measurement was established between the 3 DEXA systems. Cross-calibration equations for the lumbar spine BMD values need to be applied to transform the Hologic Discovery A or GE Lunar iDXA measurements into SONIALVISION SMIT measurements to comply with the ISCD standards for patient continuity of care in assessment during clinical diagnosis.

Project description:BackgroundMuscle weakness is a key factor in the increase risk of falls and might also play a significant role in the increase of risk of hip fracture. Computed tomography-measured muscle size and muscle density are well-established imaging biomarkers used in studies of physical function, frailty or cancer, but limited to hip fracture. In particular, it is warranted to have a better understanding of the performance of muscle size and density in the discrimination of acute hip fractures. We also aim to determine age-related differences of muscle size and density in healthy controls and hip fracture patients.MethodsFour hundred thirty-eight low-energy acute hip fracture cases and 316 healthy controls from the China Action on Spine and Hip Status study were included in the study. Muscle cross-sectional area and density were measured for the gluteus maximus and gluteus medius and minimus. Areal bone mineral density (aBMD) of the femoral neck and total hip was measured. Using propensity score matching, we generated three samples with cases and controls matched for age, body mass index, and gender: femoral neck fracture (FNF), intertrochanteric fracture (ITF), and any hip fracture vs. controls, respectively.ResultsHandgrip strength, gluteus muscle area and density, and bone parameters of the matched hip fracture groups were lower than those of the correspondence control groups, respectively (P < 0.05). The univariate analysis showed that associations of aBMD with FNF and with ITF were significantly weaker than associations between fracture and muscle parameters. Gluteus medius and minimus muscle density showed the highest areas under the curve (AUC) with FNF (0.88, 95% confidence interval, 0.85-0.92) and trochanteric fracture (0.95, 95% confidence interval, 0.92-0.97). The model including all muscle and bone parameters provided the highest AUC (FNF: AUC 0.912; ITF: AUC 0.958), and AUC results of another selected model without muscle density showed that association with fracture significantly dropped (FNF: AUC 0.755; ITF: AUC 0.858). Separate results for the two age groups younger and older than 70 years showed no age-related significant differences in discriminate models.ConclusionsMuscle density performs better than aBMD from hip computed tomography X-ray absorptiometry and muscle size in discrimination of hip fracture. Combination of aBMD and muscle density provided the best discrimination. The integration of muscle assessments may trigger a paradigm shift in hip fracture prediction. Gluteus muscle density should also be evaluated as treatment outcome.

Project description:Bone mineral density (BMD) measurement using dual-energy X-ray absorptiometry (DXA) is considered a diagnostic parameter for osteoporosis by the World Health Organization (WHO). DXA densitometers have different scanning modes for BMD measurements, although the specific scanning modes vary based upon the manufacturer. For DXA machines manufactured by Hologic, which are used globally, a range of scanning modes exist, including but not limited to (in order of decreasing spatial resolution) Array, Fast Array, and Express Array. Only a handful of prior studies have compared the reproducibility of BMD measurements across scan modes. The present study aimed to add to this body of literature by investigating the differences in BMD measured between 3 scanning modes in Hologic DXA machines at 19 different health centers. As part of cross-calibration activities for two multi-center studies in China measuring BMD, the European spine phantom (ESP, 1.000 g/cm2) was scanned on 19 different Hologic DXA machines. To measure differences in BMD between the 3 scan modes most commonly found on the Hologic models available (i.e., Array, Fast Array, Express Array), the ESP measurement was performed 10 times for each scan mode on each Hologic DXA machine. One-sample t test was used to compare the average difference between the measured ESP results of the 3 scanning modes at each hospital and reference ESP values. Single factor analysis of variance was performed to compare the average differences between the pairs of scanning modes using the reference ESP. Statistically significant differences between the measured ESP results with reference ESP values were found with each scanning mode at 19 hospitals (all p values <0.05). Consistent with this finding, differences in average BMD between the Array mode and Fast Array mode were invariably the smallest compared to differences seen between the other two pairs of scan modes. Significant differences were observed between average ESP BMD for the Array and Express Array scan modes (0.971 ± 0.013 vs 0.935 ± 0.027, p < 0.001), and between Fast Array and Express Array scan modes (0.972 ± 0.012 vs 0.935 ± 0.027, p < 0.001). However, no significant difference in average ESP BMD was observed between the Array and Fast Array scan modes (0.971 ± 0.013 vs 0.972 ± 0.012, p = 0.997). The selection of ideal scanning mode requires a balance of scanning time, radiation exposure, and measurement accuracy. In this ex vivo study, the Fast Array scanning mode appeared to be a reasonable choice compared with Array and Express Array for BMD measurements by Hologic DXA. Future in vivo studies can help guide the clinical application of these findings.

Project description:BackgroundBody composition assessment aids evaluation of energy stores and the impact of diseases and interventions on child growth. Current United States pediatric reference ranges from the National Health and Nutrition Examination Survey (NHANES) include 20% of children with obesity, body mass index of ≥95th percentile.ObjectivesThis study aimed to develop dual energy X-ray absorptiometry (DXA) based reference ranges in a diverse cohort with low-obesity prevalence from the Bone Mineral Density in Childhood Study (BMDCS).MethodsThis is a secondary analysis of a longitudinal, prospective, observational cohort. Healthy children (height and BMI within 3rd to 97th percentiles, ages 5-19 y at enrollment), from 5 United States centers were measured annually for ≤7 visits. Whole body scans were acquired using Hologic scanners. A subsample underwent repeat measurements to determine precision. We generated reference ranges for appendicular and total lean soft tissue mass index (LSTM Index), fat mass index (FMI), and other body composition measures. Resulting curves were compared to NHANES and across subgroups. Sex and age-specific equations were developed to adjust body composition Z-scores for height Z score.ResultsWe obtained 9846 scans of 2011 participants (51% female, 22% Black, 17% Hispanic, 48% White, 7% Asian/Pacific Islander, and 6% with obesity). Precision (percent coefficient of variation) ranged from 0.7% to 1.96%. Median and-2 standard deviation curves for BMDCS and NHANES were similar, but NHANES +2 standard deviation LSTM Index and FMI curves were distinctly greater than the respective BMDCS curves. Subgroup differences were more extreme for appendicular LSTM Index-Z (mean ± SD: Asian -0.52 ± 0.93 compared with Black 0.77 ± 0.87) than for FMI-Z (Hispanic 0.29 ± 0.98 compared with Black -0.14 ± 1.1) and were smaller for Z-scores adjusted for height Z-score.ConclusionsThese reference ranges add to sparse normative data regarding body composition in children and adolescents and are based on a cohort with an obesity prevalence similar to current BMI charts. Awareness of subgroup differences aids in interpreting results.

Project description:Introduction The WHO definition of osteoporosis, and published BMD (Bone Mineral Density) references ranges, do not consider differences in bone size. Because it is a two-dimensional technique, and cannot measure bone depth, aBMD (areal BMD) measured using DXA (Dual-energy X-Ray Absorptiometry) is affected by bone size variability. Mathematical models have been devised to correct aBMD for bone size, but these are confounded by variations in soft tissue surrounding bone. Confirmation of the actual quantitative effect on clinical results for patients requires precise changes in bone size and mineral density, but studies of humans and animals are limited by the inability to precisely control these in natural bones. Purpose The objectives of this experiment were to obtain precise, repeatable, quantitative data from sets of artificial vertebrae to confirm the dependence of aBMD on bone size in clinical practice, and to test the effect of applying corrections based on assumptions that the vertebrae were simple geometric shapes to produce corrected BMAD (Bone Mineral Apparent Density). Methods and materials Four sets of artificial bones, each set containing four cylinders of different diameters but identical in height, were constructed by casting a mixture of epoxy resin and calcium carbonate powder into a mould. The cylinders were considered to be artificial vertebrae L1 to L4 so that all four in a set may be tested in a single scan. The X-Ray attenuation of the material used was varied between the sets, to represent differences in BMD. Each set of vertebrae was inserted into a soft-tissue analogue and DXA scanned, in the anteroposterior position, with the GE Lunar Prodigy and the Hologic Discovery. Results The results verify the theoretical direct proportionality between aBMD and diameter, confirming that aBMD is significantly affected by bone size. Applying a BMAD correction, by assuming the vertebrae to be cylinders, reduced the effect of change in bone diameter by approximately two orders of magnitude to an insignificant level. Conclusion This experiment has confirmed that BMD measured using DXA, accepted in clinical practice as the “gold standard” means of diagnosing osteoporosis, could lead to misdiagnosis because it is significantly affected by differences in bone size. Graphical abstract Unlabelled Image Highlights • Dual-Energy X-Ray Absorptiometry is two-dimensional; results affected by bone size.• Those with small bones may be over-diagnosed; those with large bones under-diagnosed.• Experiment with artificial vertebrae confirms theory and previous clinical studies.

Dataset Information

Comparative measurements of bone mineral density and bone contrast values in canine femora using dual-energy X-ray absorptiometry and conventional digital radiography.

Background

Results

Conclusions

Publications

Comparative measurements of bone mineral density and bone contrast values in canine femora using dual-energy X-ray absorptiometry and conventional digital radiography.

Similar Datasets

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