Lumbar spine quantitative computed tomography (QCT) is a better predictor of vertebral fracture in boys with Duchenne muscular dystrophy (DMD) than either DXA or peripheral QCT

The high-resolution peripheral quantitative computed tomography (HR-pQCT) provides unprecedented visualization of bone microstructure and the basis for constructing patient-specific microfinite element (μFE) models. Based on HR-pQCT images, we have developed a plate-and-rod μFE (PR μFE) method for whole bone segments using individual trabecula segmentation (ITS) and an adaptive cortical meshing technique. In contrast to the conventional voxel approach, the complex microarchitecture of the trabecular compartment is simplified into shell and beam elements based on the trabecular plate-and-rod configuration. In comparison to voxel-based μFE models of μCT and measurements from mechanical testing, the computational and experimental gold standards, nonlinear analyses of stiffness and yield strength using the HR-pQCT-based PR μFE models demonstrated high correlation and accuracy. These results indicated that the combination of segmented trabecular plate-rod morphology and adjusted cortical mesh adequately captures mechanics of the whole bone segment. Meanwhile, the PR μFE modeling approach reduced model size by nearly 300-fold and shortened computation time for nonlinear analysis from days to within hours, permitting broader clinical application of HR-pQCT-based nonlinear μFE modeling. Furthermore, the presented approach was tested using a subset of radius and tibia HR-pQCT scans of patients with prior vertebral fracture in a previously published study. Results indicated that yield strength for radius and tibia whole bone segments predicted by the PR μFE model was effective in discriminating vertebral fracture subjects from nonfractured controls. In conclusion, the PR μFE model of HR-pQCT images accurately predicted mechanics for whole bone segments and can serve as a valuable clinical tool to evaluate musculoskeletal diseases.

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Effect of spinal degenerative changes on volumetric bone mineral density of the central skeleton as measured by quantitative computed tomography

Acta Radiologica ◽

10.1080/02841850510012661 ◽

2005 ◽

Vol 46 (3) ◽

pp. 269-275 ◽

Cited By ~ 40

Author(s):

G. Guglielmi ◽

I. Floriani ◽

V. Torri ◽

J. Li ◽

C. van Kuijk ◽

...

Keyword(s):

Computed Tomography ◽

Bone Mineral Density ◽

Lumbar Spine ◽

Bone Mineral ◽

Vertebral Fractures ◽

Quantitative Computed Tomography ◽

Degenerative Changes ◽

Volumetric Bone Mineral Density ◽

Mineral Density ◽

The Impact

Purpose: To evaluate the impact of degenerative changes due to osteoarthritis (OA) at the spine on volumetric bone mineral density (BMD) as measured by volumetric quantitative computed tomography (vQCT). Material and Methods: Eighty‐four elderly women (mean age 73±6 years), comprising 33 with vertebral fractures assessed by radiographs and 51 without vertebral fractures, were studied. Trabecular, cortical, and integral BMD were examined at the spine and hip using a helical CT scanner and were compared to dual X‐ray absorptiometry (DXA) measurements at the same sites. OA changes visible on the radiographs were categorized into two grades according to severity. Differences in BMD measures obtained in the two groups of patients defined by OA grade using the described radiologic methods were compared using analysis of variance. Standardized difference (effect sizes) was also compared between radiologic methods. Results: Spinal trabecular BMD did not differ significantly between OA grade 0 and OA grade 1. Spinal cortical and integral BMD measures showed statistically significant differences, as did the lumbar spine DXA BMD measurement (13%, P = 0.02). The QCT measurements at the hip were also higher in OA 1 subjects. Femoral trabecular BMD was 13–15% higher in OA grade 1 subjects than in OA grade 0 subjects. The cortical BMD measures in the CT_TOT_FEM and CT_TROCH ROI's were also higher in the OA 1 subjects. The integral QCT BMD measures in the hip showed difference between grades OA 1 and 0. The DXA measurements in the neck and trochanter ROI's showed smaller differences (9 and 11%, respectively). There were no statistically significant differences in bone size. Conclusion: There is no evidence supporting that trabecular BMD measurements by QCT are influenced by OA. Instead, degenerative changes have an effect on both cortical and integral QCT, and on DXA at the lumbar spine and the hip. For subjects with established OA, assessment of BMD by volumetric QCT may be suggested.

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