Bone structure determined by HR-MDCT does not correlate with micro-CT of lumbar vertebral biopsies: a prospective cross-sectional human in vivo study.

Background: Osteoporosis is characterized by a deterioration of bone structure and quantity that leads to an increased risk of fractures. The primary diagnostic tool for the assessment of the bone quality is currently the dual-energy X-ray absorptiometry (DXA), which however only measures bone quantity. High-resolution multidetector computed tomography (HR-MDCT) offers an alternative approach to assess bone structure, but still lacks evidence for its validity in vivo.

Bone mineral density assessment using iterative reconstruction compared with quantitative computed tomography as the standard of reference.

This study examines the influence of iterative reconstruction on bone mineral density (BMD) measurement by comparison with standard quantitative computed tomography (QCT; reference) and two other protocols based on filtered back projection. Ten human cadaver specimens of the lumbar spine with a hydroxyapatite calibration phantom underneath, were scanned with 4 protocols: 1. standard QCT, 2.

Reviving the dinosaur: virtual reconstruction and three-dimensional printing of a dinosaur vertebra.

Purpose: To demonstrate the feasibility of using computed tomography (CT) to confirm the identity of an unprepared fossil and to use the CT dataset to separate the fossilized bone from its surrounding sediment matrix and produce a three-dimensional (3D) print.

Materials And Methods: The examined object was a plaster jacket containing an unprepared fossil. CT was performed with a 320-section multidetector unit.

Prediction of bone strength by μCT and MDCT-based finite-element-models: how much spatial resolution is needed?

Objectives: Finite-element-models (FEM) are a promising technology to predict bone strength and fracture risk. Usually, the highest spatial resolution technically available is used, but this requires excessive computation time and memory in numerical simulations of large volumes. Thus, FEM were compared at decreasing resolutions with respect to local strain distribution and prediction of failure load to (1) validate MDCT-based FEM and to (2) optimize spatial resolution to save computation time.

Retrospective comparison of triple-sequence therapies in metastatic renal cell carcinoma.

Background: The optimal sequence of targeted therapy in patients with metastatic renal cell carcinoma (mRCC) has not been defined.

Objective: To describe the efficacy and toxicity of the most common sequences of targeted therapy, namely, receptor tyrosine kinase inhibitor (rTKI) and mammalian target of rapamycin inhibitor (mTORi), in different sequences after failure of vascular endothelial growth factor signaling inhibition (VEGFi) in first-line therapy.

Design, Setting And Participants: Retrospective study of 103 patients receiving VEGFi-rTKI-mTORi (n=62) or VEGFi-mTORi-rTKI (n=41) at two German academic centers.

Texture analysis, bone mineral density, and cortical thickness of the proximal femur: fracture risk prediction.

Objective: The objectives of this study were to perform a clinical study analyzing bone quality in multidetector computed tomographic images of the femur using bone mineral density (BMD), cortical thickness, and texture algorithms in differentiating osteoporotic fracture and control subjects; to differentiate fracture types.

Methods: Femoral head, trochanteric, intertrochanteric, and upper and lower neck were segmented (fracture, n = 30; control, n = 10). Cortical thickness, BMD, and texture analysis were obtained using co-occurrence matrices, Minkowski dimension, and functional and scaling index method.

High-resolution peripheral quantitative computed tomographic imaging of cortical and trabecular bone microarchitecture in patients with type 2 diabetes mellitus.

Context: Cross-sectional epidemiological studies have found that patients with type 2 diabetes mellitus (T2DM) have a higher incidence of certain fragility fractures despite normal or elevated bone mineral density (BMD).

Objective: In this study, high-resolution peripheral quantitative computed tomography was applied to characterize cortical and trabecular microarchitecture and biomechanics in the peripheral skeleton of female patients with T2DM.

Design And Setting: A cross-sectional study was conducted in patients with T2DM recruited from a diabetic outpatient clinic.

Interrelationships between 3-T-MRI-derived cortical and trabecular bone structure parameters and quantitative-computed-tomography-derivedbone mineral density.

Recently, 3-T magnetic resonance imaging (MRI) has been introduced for bone imaging. Through higher signal-to-noise ratios, as compared to 1.5-T MRI, it promises to be a more powerful tool for the assessment of cortical and trabecular bone measures.

MR imaging of patellar instability: injury patterns and assessment of risk factors.

First-time patellar dislocation typically occurs with twisting knee motions, during which the medial ligamentous stabilizers rupture, and the patella strikes against the lateral femoral condyle. The typical injury pattern is a tear of the medial patellofemoral ligament (MPFL) and bone bruises of the patella and the lateral femoral condyle. Additionally, complex injuries to bone, cartilage, and ligaments may occur.

Assessment of trabecular bone structure using MDCT: comparison of 64- and 320-slice CT using HR-pQCT as the reference standard.

Objectives: The aim of our study was to perform trabecular bone structure analysis with images from 64- and 320-slice multidetector computed tomography (MDCT) and to compare these with high-resolution peripheral computed tomography (HR-pQCT).

Materials And Methods: Twenty human cadaver distal forearm specimens were imaged on a 64- and 320-slice MDCT system at 120 kVp, 200 mA and 135 kVp, 400 mA (in-plane pixel size 234 microm; slice thickness 500 microm). HR-pQCT imaging was performed at an isotropic voxel size of 41 microm.

Evaluation of correction methods for coil-induced intensity inhomogeneities and their influence on trabecular bone structure parameters from MR images.

Magnetic resonance (MR) imaging-based quantitative trabecular bone structure analysis has gained increasing interest in osteoporotic fracture risk assessment and treatment evaluation related to osteoporosis. In vivo MR images of anatomic regions such as the proximal femur and distal tibia are generally acquired with a surface coil in order to obtain sufficient sensitivity and resolution for quantification of the trabeculae. However, these coils introduce intensity inhomogeneities which affect the trabecular bone structure analysis.

Assessment of trabecular bone structure of the calcaneus using multi-detector CT: correlation with microCT and biomechanical testing.

The prediction of bone strength can be improved when determining bone mineral density (BMD) in combination with measures of trabecular microarchitecture. The goal of this study was to assess parameters of trabecular bone structure and texture of the calcaneus by clinical multi-detector row computed tomography (MDCT) in an experimental in situ setup and to correlate these parameters with microCT (microCT) and biomechanical testing. Thirty calcanei in 15 intact cadavers were scanned using three different protocols on a 64-slice MDCT scanner with an in-plane pixel size of 208 microm and 500 microm slice thickness.

Trabecular bone structure analysis in the osteoporotic spine using a clinical in vivo setup for 64-slice MDCT imaging: comparison to microCT imaging and microFE modeling.

Assessment of trabecular microarchitecture may improve estimation of biomechanical strength, but visualization of trabecular bone structure in vivo is challenging. We tested the feasibility of assessing trabecular microarchitecture in the spine using multidetector CT (MDCT) on intact human cadavers in an experimental in vivo-like setup. BMD, bone structure (e.

CT-based patient-specific modeling of glenoid rim defects: a feasibility study.

Objective: Reconstruction of glenoid bone defects requires accurate preoperative planning. The purpose of this study is to present a method for quantifying the defect size and generating a 3D model of the bone graft for augmentation by matching the fractured glenoid with the contralateral side.

Materials And Methods: Ten paired shoulders from five cadavers (subjects: three women and two men; mean age, 85 years) and 60 paired shoulders in 30 patients (controls: nine women and 21 men; mean age, 21 years) were examined using CT to determine bilateral comparability by assessment of the maximum glenoid diameters, surface area, and volume.

Analyser-based tomography images of cartilage.

Analyser-based imaging expands the performance of X-ray imaging by utilizing not only the absorption properties of X-rays but also the refraction and scatter rejection (extinction) properties. In this study, analyser-based computed tomography has been implemented on imaging an articular cartilage sample, depicting substructural variations, without overlay, at a pixel resolution of 3.6 microm.

Accessory navicular bone: when ankle pain does not originate from the ankle.

A young girl suffering from ankle pain occurring after gymnastics classes was referred to the rheumatology department by an orthopedic surgeon because a rheumatological condition was suspected to cause her symptoms. MRI was useful in pointing to the correct diagnosis of accessory navicular bone (AN). The morphological classification of ANs is discussed and the imaging modalities for diagnosis are presented.

Diffraction enhanced imaging of articular cartilage and comparison with micro-computed tomography of the underlying bone structure.

The goal of this study was to explore the role of diffraction enhanced X-ray imaging (DEI) for assessing changes in osteoarthritic cartilage and correlating the findings with concurrent changes in the underlying bone imaged using micro-computed tomography (microCT). DEI was used to image femoral head specimens at various beam energies. DEI utilizes a monochromatic, highly collimated beam, with an analyzer crystal that selectively weights out photons according to the angle they have been deviated with respect to the original direction.

X-ray detection of structural orientation in human articular cartilage.

Objective: To determine the feasibility of detecting the structural orientation in cartilage with Diffraction Enhanced X-Ray Imaging.

Design: Human tali and femoral head specimens were Diffraction Enhanced X-Ray Imaged (DEI) at the SYRMEP beamline at Elettra at various energy levels to detect the architectural arrangement of collagen within cartilage. DEI utilizes a monochromatic and highly collimated beam, with an analyzer crystal that selectively weights out photons according to the angle they have been deviated with respect to the original direction.

Local differences in the trabecular bone structure of the proximal femur depicted with high-spatial-resolution MR imaging and multisection CT.

Rationale And Objectives: The authors performed this study to investigate structural variations in the trabecular bone of the proximal femur at high-resolution magnetic resonance (MR) imaging and high-resolution multisection computed tomography (CT).

Materials And Methods: Bone mineral density (BMD) was measured in 36 proximal human femur specimens by using dual x-ray absorptiometry. High-resolution MR imaging was performed at 1.

Micro-computed tomography evaluation of trabecular bone structure on loaded mice tail vertebrae.

Study Design: A micro-computed tomography (CT) study of the trabecular bone structure on loaded mice tail vertebral bodies was conducted.

Objective: To depict and characterize changes in the trabecular bone structure of mice tail vertebral bodies after in vivo application of static compressive load.

Summary Of Background Data: Static compressive loading leads to significant structural changes in murine tail intervertebral discs, such as disorganization of the anulus fibrosus, increase in apoptosis, and associated loss of cellularity.

MicroCT evaluation of normal and osteoarthritic bone structure in human knee specimens.

Although trabecular bone structure has been evaluated, variation with knee compartment and depth from joint surface is not completely understood. Cadaver knees were evaluated with microcomputed tomography analysis for these variations. Objective differences were compared between: medial vs.