Comparison of the diagnostic accuracy of diffusion-weighted and dynamic contrast-enhanced MRI with 18F-FDG PET/CT to differentiate osteomyelitis from Charcot neuro-osteoarthropathy in diabetic foot.

PURPOSE: To compare the diagnostic accuracy of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced-magnetic resonance imaging (DCE-MRI) involving two region of interest (ROI) sizes with 18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) to differentiate diabetic foot osteomyelitis (DFO) from Charcot neuro-osteoarthropathy (CN). METHOD: Thirty-one diabetic patients were included in this prospective study. Two readers independently evaluated DWI (apparent diffusion coefficient [ADC] and high-b-value signal pathological-to-normal bone ratio [DWIr]) and DCE-MRI parameters (Ktrans, Kep, Ve, internal area under the gadolinium curve at 60 s [iAUC60] and time intensity curve [TIC]) using two different ROI sizes, and 18F-FDG PET/CT parameters (visual assessment, SUVmax, delayed SUVmax, and percentage changes between SUVmax and delayed SUVmax). Techniques were compared by univariate analysis using the area under the receiver operating characteristic curve [AUC]. Reliability was analyzed with Kappa and Intraclass correlation [ICC]. RESULTS: DWIr, Ktrans and iAUC60 showed better diagnostic accuracy (AUC = 0.814-0.830) and reliability (ICC > 0.9) for large than for small ROIs (AUC = 0.736-0.750; ICC = 0.6 in Ktrans, 0.8 in DWIr and iAUC60). TIC showed moderate diagnostic performance (AUC = 0.739-0.761) and reliability (κ 0.7). Visual assessment of 18F-FDG PET/CT demonstrated a significantly higher accuracy (AUC = 0.924) than MRI parameters. Semi-quantitative 18F-FDG PET/CT parameters did not provide significant improvement over visual analysis (AUC = 0.848-0.903). CONCLUSION: DWIr, Ktrans and iAUC60 allowed reliable differentiation of DFO and CN, particularly for large ROIs. Visual assessment of 18F-FDG PET/CT was the most accurate technique for differentiation.

Caracterización de la fisiología restrictiva del ventrículo derecho mediante flujo 4D / 4-D flow characterization of right ventricular restrictive physiology

Abstract: Right ventricular restrictive physiology (RVRP) occurs in diverse clinical scenarios, most frequently after repair of Tetralogy of Fallot (TOF). Cardiac magnetic resonance (CMR) can comprehensively evaluate RVRP using 4D flow along with anatomical and fibrosis characterization. Also, RVRP is associated with less pulmonary regurgitation and fewer right ventricle enlargement; its long term protective role is debated. RVRP is a challenging and relevant diagnosis, which hallmark is the presence of antegrade pulmonary arterial Flow in late diastole throughout the respiratory cycle. Also, other hemodynamic findings could aid such us flow in; caval veins, suprahepatic, coronary sinus and tricuspid valve. Obtaining all these flow curves is virtually impossible by echocardiography. CMR with 4DF is a unique and powerful technique enabling this comprehensive hemodynamic evaluation as depicted in this case.