Assessment of myocardial partition coefficient of gadolinium (λ) in dilated cardiomyopathy and its impact on segmental and global systolic function.

PURPOSE: 1) To assess the myocardial partition coefficient (λ) of gadolinium quantified using T1 mapping in dilated cardiomyopathy (DCM); and 2) to assess the impact of increased λ on left ventricular (LV) circumferential strain and ejection fraction in DCM. MATERIALS AND METHODS: Seventeen patients with DCM and 11 controls were prospectively included. All patients and controls underwent a 1.5 T MRI using: 1) cine to quantify LV volumes and function; 2) tagging to quantify circumferential strain in mid-LV; 3) T1 mapping before and 9 minutes after contrast injection to quantify R1, ΔR1, and λ; and 4) inversion recovery 3D Flash was used to assess late gadolinium enhancement (LGE) 10 minutes after Gd DOTA injection (0.2 mmol/kg). We used Student's t-test to compare means, Pearson's test for correlation assessment, and a mixed linear model to integrate the dependency between myocardial segments. RESULTS: No difference in median λ was measured between patients with (0.52 [interquartile range = 0.48-0.56]) and without enhancement on LGE (0.51 [0.47-0.54]; P = 0.07). Circumferential strain value measured in each segment was correlated with the λ measured in the corresponding segment (r = 0.55; P < 0.0001). Multivariate analysis revealed a significant link between the λ in each segment and circumferential strain (0.002 ± 0.001; P = 0.009) and also with ejection fraction (-0.001 ± 0.0008; P = 0.04). CONCLUSION: In DCM, λ correlates independently with circumferential strain and ejection fraction, suggesting that there is a link between λ and systolic function.

Bone texture analysis is correlated with three-dimensional microarchitecture and mechanical properties of trabecular bone in osteoporotic femurs.

Fracture of the proximal femur is a major public health problem in elderly persons. It has recently been suggested that combining texture analysis and bone mineral density measurement improves the failure load prediction in human femurs. In this study, we aimed to compare bone texture analysis with three-dimensional (3D) microarchitecture and mechanical properties of trabecular bone in osteoporotic femurs. Eight femoral heads from osteoporotic patients who fractured their femoral neck provided 31 bone cores. Bone samples were studied using a new high-resolution digital X-ray device (BMA™, D3A Medical Systems) allowing for texture analysis with fractal parameter H (mean), and were examined using micro-computed tomography (microCT) for 3D microarchitecture. Finally, uniaxial compression tests to failure were performed to estimate failure load and apparent modulus of bone samples. The fractal parameter H (mean) was strongly correlated with bone volume fraction (BV/TV) (r = 0.84) and trabecular thickness (Tb.Th) (r = 0.91) (p < 0.01). H (mean) was also markedly correlated with failure load (r = 0.84) and apparent modulus (r = 0.71) of core samples (p < 0.01). Bone volume fraction (BV/TV) and trabecular thickness (Tb.Th) demonstrated significant correlations with failure load (r = 0.85 and 0.72, respectively) and apparent modulus (r = 0.72 and 0.64, respectively) (p < 0.01). Overall, the best predictors of failure load were H (mean), bone volume fraction, and trabecular thickness, with r (2) coefficients of 0.83, 0.76, and 0.80 respectively. This study shows that the fractal parameter H (mean) is correlated with 3D microCT parameters and mechanical properties of femoral head bone samples, which suggests that radiographic texture analysis is a suitable approach for trabecular bone microarchitecture assessment in osteoporotic femurs.

Treatment of symptomatic para-articular intraosseous cysts by percutaneous injection of bone cement.

PURPOSE: To describe the technique and clinical outcome of percutaneous injection of bone cement in the treatment of symptomatic para-articular intraosseous cysts. MATERIALS AND METHODS: Five patients (three men, two women; mean age 35 years) with painful para-articular intraosseous cysts were treated by percutaneous injection of bone cement under combined fluoroscopic and computed tomography (CT) guidance. The lesions were all located in weight-bearing bones, involving the acetabulum, proximal tibia, distal tibia, talus, and calcaneus, respectively. RESULTS: The average amount of bone cement injected was 2.1 ml (range, 0.6-3.5 ml). Calcium phosphate cement was used in four cases and acrylic cement in one case. There were no immediate or delayed complications. Full pain relief was obtained between 1 and 4 weeks after treatment. All patients made a complete recovery and were pain-free at their last visit. CONCLUSIONS: Percutaneous injection of bone cement was a safe and efficient technique in the management of symptomatic para-articular intraosseous cysts in our population.