Magnetic resonance imaging (MRI) and 2-[18F]-fluoro-2-deoxy-D-glucose (18F-FDG) Positron Emission Tomography, paired with Computed Tomography (PET/CT) are two indicated advanced imaging modalities in the complicated diagnostic work-up of osteomyelitis. PET/MRI is a relatively novel hybrid modality with suggested applications in musculoskeletal infection imaging. The goal of this study was to assess the value of hybrid 18F-FDG PET/MRI for chronic osteomyelitis diagnosis and surgical planning. Five suspected chronic osteomyelitis patients underwent a prospective 18F-FDG single-injection/dual-imaging protocol with hybrid PET/CT and hybrid PET/MR. Diagnosis and relevant clinical features for the surgeon planning treatment were compared. Subsequently, 36 patients with 18F-FDG PET/MRI scans for suspected osteomyelitis were analysed retrospectively. Sensitivity, specificity, and accuracy were determined with the clinical assessment as the ground truth. Standardized uptake values (SUV) were measured and analysed by means of receiver operating characteristics (ROC).Aim
Method
Bio-Active Glass (BAG) is a promising bone graft substitute for large bone defect reconstruction because of its favourable osteoconductive, antibacterial and angiogenic properties. Potentially, it could also mechanically reinforce the defect, thus making it suitable for load-bearing defects. However, the mechanical properties of the reconstructive layer consisting of BAG/bone allograft mixtures are unknown. The goals of this study therefore were, first, to measure the mechanical properties of different BAG/bone graft mixtures and, second, to investigate to what extent such mixtures could reinforce distal tibial defects using micro-FE analysis and high-resolution CT scans. Four different BAG/bone graft mixtures were impacted in a cylindrical holder, mechanically tested in confined compression and scanned with micro-CT. From these images, bone graft material and glass were segmented using two different threshold values. The interface between bone and BAG was modelled separately by dilating the glass phase. Micro-Finite-Element (FE) models of the composites were made using a Young's modulus of 2.5 GPa for bone and 35 GPa for BAG. The Young's modulus for the interface region was determined by fitting experimental and micro-FE results for the same specimens. (82 μm resolution) CT scans of a 9 mm region of the distal tibia of 3 subjects were used. Micro-FE models of this region were made to determine its stiffness in the original state, with a simulated cortical defect and after a mixture of BAG/bone was modelled in the defect.Background
Materials and Methods
