Improved Detection of Foreign Bodies on Radiographs Using X-ray Dark-Field and Phase-Contrast Imaging

Purpose: The aim of this study was to investigate whether the detection of foreign bodies can be improved using dark-field and phase-contrast radiography compared with conventional (transmission) radiographs. Materials and Methods: Experiments were performed using ex vivo pig paws, which were prepared with differently sized foreign bodies of metal, wood, and glass (n = 10 each). Paws without foreign bodies served as controls (n = 30). All images were acquired using an experimental grating-based large object radiography system. Five blinded readers (second- to fourth-year radiology residents) were asked to assess the presence or absence of any foreign body. Sensitivity and specificity for the detection of metal, wood, glass, and any foreign body were calculated and compared using McNemar test and generalized linear mixed models. Results: Sensitivity for the detection of metal foreign bodies was 100% for all readers and image combinations. The sensitivity for the detection of wooden foreign bodies increased from 2% for transmission images to 78% when dark-field images were added (P < 0.0001). For glass foreign bodies, sensitivity increased from 84% for transmission images to 96% when adding phase-contrast images (P = 0.041). Sensitivity for the detection of any foreign body was 91% when transmission, dark-field, and phase-contrast images were viewed simultaneously, compared with 62% for transmission images alone (P < 0.0001). Specificity was 99% to 100% across all readers and radiography modalities. Conclusions: Adding dark-field images substantially improves the detection of wooden foreign bodies compared with the analysis of conventional (transmission) radiographs alone. Detection of glass foreign bodies was moderately improved when adding phase-contrast images

Improved In vivo Assessment of Pulmonary Fibrosis in Mice using X-Ray Dark-Field Radiography

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung disease with a median life expectancy of 4-5 years after initial diagnosis. Early diagnosis and accurate monitoring of IPF are limited by a lack of sensitive imaging techniques that are able to visualize early fibrotic changes at the epithelial-mesenchymal interface. Here, we report a new x-ray imaging approach that directly visualizes the air-tissue interfaces in mice in vivo. This imaging method is based on the detection of small-angle x-ray scattering that occurs at the air-tissue interfaces in the lung. Small-angle scattering is detected with a Talbot-Lau interferometer, which provides the so-called x-ray dark-field signal. Using this imaging modality, we demonstrate-for the first time-the quantification of early pathogenic changes and their correlation with histological changes, as assessed by stereological morphometry. The presented radiography method is significantly more sensitive in detecting morphological changes compared with conventional x-ray imaging, and exhibits a significantly lower radiation dose than conventional x-ray CT. As a result of the improved imaging sensitivity, this new imaging modality could be used in future to reduce the number of animals required for pulmonary research studies

Challenges and special aspects of pulmonary hypertension in middle- to low-income regions: JACC state-of-the-art review

Challenges and special aspects related to the management and prognosis of pulmonary hypertension (PH) in middle- to low-income regions (MLIRs) range from late presentation to comorbidities, lack of resources and expertise, cost, and rare options of lung transplantation. Expert consensus recommendations addressing the specific challenges for prevention and therapy of PH in MLIRs with limited resources have been lacking. To date, 6 MLIR-PH registries containing mostly adult patients with PH exist. Importantly, the global prevalence of PH is much higher in MLIRs compared with high-income regions: group 2 PH (left heart disease), pulmonary arterial hypertension associated with unrepaired congenital heart disease, human immunodeficiency virus, or schistosomiasis are highly prevalent. This consensus statement provides selective, tailored modifications to the current PH guidelines to address the specific challenges faced in MLIRs, resulting in the first pragmatic and cost-effective consensus recommendations for PH care providers, patients, and their families

Echocardiography for the Assessment of Pulmonary Hypertension and Congenital Heart Disease in the Young

While invasive assessment of hemodynamics and testing of acute vasoreactivity in the catheterization laboratory is the gold standard for diagnosing pulmonary hypertension (PH) and pulmonary vascular disease (PVD) in children, transthoracic echocardiography (TTE) serves as the initial diagnostic tool. International guidelines suggest several key echocardiographic variables and indices for the screening studies when PH is suspected. However, due to the complex anatomy and special physiological considerations, these may not apply to patients with congenital heart disease (CHD). Misinterpretation of TTE variables can lead to delayed diagnosis and therapy, with fatal consequences, or&ndash;on the other hand-unnecessary invasive diagnostic procedures that have relevant risks, especially in the pediatric age group. We herein provide an overview of the echocardiographic workup of children and adolescents with PH with a special focus on children with CHD, such as ventricular/atrial septal defects, tetralogy of Fallot or univentricular physiology. In addition, we address the use of echocardiography as a tool to assess eligibility for exercise and sports, a major determinant of quality of life and outcome in patients with PH associated with CHD

Grating-based X-ray dark-field imaging : a new paradigm in radiography

Grating-based X-ray dark-field contrast is an emerging new imaging modality that is demonstrating particularly high potential for radiography. The signal in dark-field X-ray imaging is determined by small-angle X-ray scattering at structures typically below the spatial resolution of the imaging setup. Thus, this technique not only yields complementary information but also visualizes information that lies under the resolution limit for conventional, absorption-based radiography. Grating-based X-ray dark-field imaging has been shown to be feasible with both synchrotron radiation and conventional X-ray tubes. Lung, breast, and bone imaging have been identified as the applications promising the main impact, but other applications are on the horizon. Specifically, dark-field radiography has been used to detect pulmonary emphysema and assesses its regional distribution in mice and holds promise to improve the visualization of micro-calcifications in mammography and yields information about bone microstructure. Further technical developments are required to make the technique suitable for clinical use

Digitize! Online Panel Survey (SUF edition)

Full edition for scientific use. The Digitize! Online Panel Survey is an offline-recruited Austrian opinion survey which measures attitudes and behavior towards several social phenomena and issues. Topics include, amongst others, attitudes towards work, immigration, family, health, environment, and media behavior as well as opinions on political events or parties in Austria. The survey also consists of general issue items and socio-demographic variables