AIM To evaluated vascular dynamic processes in the liver of hereditary hemorrhagic telangiectasia(HHT) patients by ultrasound(US) considering quantitative analytic methods. METHODS The imaging features on US and contr...AIM To evaluated vascular dynamic processes in the liver of hereditary hemorrhagic telangiectasia(HHT) patients by ultrasound(US) considering quantitative analytic methods. METHODS The imaging features on US and contrast-enhanced ultrasound(CEUS) in 18 patients diagnosed with HHT were retrospectively analyzed. Regarding CEUS, realtime contrast harmonic imaging and sulfur hexafluoridefilled microbubbles were used. RESULTS HVa Ms were identified in all 18 patients. By US, the two major Caselitz criteria could be detected in 55.6% patients. "Color spots" were detected in 72.2% of the cases. Respecting sonographic grading criteria by Buscarini, grade 3 could be demonstrated most frequent(40%). By CEUS, all the patients showed quick and early hyperenhancement during the arterial phase. Significant lowest time to peak(TTP) and highest area under the curve(AUC) values were identified in the hepatic artery(TTP: 69.8%; AUC: 100%) and highest TTP and lowest AUC in the hepatic parenchyma and the portal vein. CONCLUSION For the first time we analyzed CEUS findings of a group of HHT patients regarding macro- and microcirculation. Our data demonstrate significant differences in TTP and AUC values in the four selected regions: hepatic artery, shunt region, portal vein and hepatic parenchyma.展开更多
The first and last mile of a railway journey, in both freight and transit applications, constitutes a high effort and is either non-productive(e.g. in the case of depot operations) or highly inefficient(e.g. in indust...The first and last mile of a railway journey, in both freight and transit applications, constitutes a high effort and is either non-productive(e.g. in the case of depot operations) or highly inefficient(e.g. in industrial railways). These parts are typically managed on-sight, i.e. with no signalling and train protection systems ensuring the freedom of movement. This is possible due to the rather short braking distances of individual vehicles and shunting consists. The present article analyses the braking behaviour of such shunting units. For this purpose, a dedicated model is developed. It is calibrated on published results of brake tests and validated against a high-definition model for lowspeed applications. Based on this model, multiple simulations are executed to obtain a Monte Carlo simulation of the resulting braking distances. Based on the distribution properties and established safety levels, the risk of exceeding certain braking distances is evaluated and maximum braking distances are derived. Together with certain parameters of the system, these can serve in the design and safety assessment of driver assistance systems and automation of these processes.展开更多
文摘AIM To evaluated vascular dynamic processes in the liver of hereditary hemorrhagic telangiectasia(HHT) patients by ultrasound(US) considering quantitative analytic methods. METHODS The imaging features on US and contrast-enhanced ultrasound(CEUS) in 18 patients diagnosed with HHT were retrospectively analyzed. Regarding CEUS, realtime contrast harmonic imaging and sulfur hexafluoridefilled microbubbles were used. RESULTS HVa Ms were identified in all 18 patients. By US, the two major Caselitz criteria could be detected in 55.6% patients. "Color spots" were detected in 72.2% of the cases. Respecting sonographic grading criteria by Buscarini, grade 3 could be demonstrated most frequent(40%). By CEUS, all the patients showed quick and early hyperenhancement during the arterial phase. Significant lowest time to peak(TTP) and highest area under the curve(AUC) values were identified in the hepatic artery(TTP: 69.8%; AUC: 100%) and highest TTP and lowest AUC in the hepatic parenchyma and the portal vein. CONCLUSION For the first time we analyzed CEUS findings of a group of HHT patients regarding macro- and microcirculation. Our data demonstrate significant differences in TTP and AUC values in the four selected regions: hepatic artery, shunt region, portal vein and hepatic parenchyma.
基金funding of the SAMIRA project by the European Regional Development Fund under grant number 0801689
文摘The first and last mile of a railway journey, in both freight and transit applications, constitutes a high effort and is either non-productive(e.g. in the case of depot operations) or highly inefficient(e.g. in industrial railways). These parts are typically managed on-sight, i.e. with no signalling and train protection systems ensuring the freedom of movement. This is possible due to the rather short braking distances of individual vehicles and shunting consists. The present article analyses the braking behaviour of such shunting units. For this purpose, a dedicated model is developed. It is calibrated on published results of brake tests and validated against a high-definition model for lowspeed applications. Based on this model, multiple simulations are executed to obtain a Monte Carlo simulation of the resulting braking distances. Based on the distribution properties and established safety levels, the risk of exceeding certain braking distances is evaluated and maximum braking distances are derived. Together with certain parameters of the system, these can serve in the design and safety assessment of driver assistance systems and automation of these processes.
