A topology optimization method based on the solid isotropic material with penalization interpolation scheme is utilized for designing gradient coils for use in magnetic resonance microscopy. Unlike the popular stream ...A topology optimization method based on the solid isotropic material with penalization interpolation scheme is utilized for designing gradient coils for use in magnetic resonance microscopy. Unlike the popular stream function method, the proposed method has design variables that are the distribution of conductive material. A voltage-driven transverse gradient coil is proposed to be used as micro-scale magnetic resonance imaging（MRI） gradient coils, thus avoiding introducing a coil-winding pattern and simplifying the coil configuration. The proposed method avoids post-processing errors that occur when the continuous current density is approximated by discrete wires in the stream function approach. The feasibility and accuracy of the method are verified through designing the z-gradient and y-gradient coils on a cylindrical surface.Numerical design results show that the proposed method can provide a new coil layout in a compact design space.展开更多
The development of second generation ultrasound (US) contrast-medium and specific imaging techniques with dedicated softwares, allows to observe the liver perfusion in real time, becoming an useful and less invasive m...The development of second generation ultrasound (US) contrast-medium and specific imaging techniques with dedicated softwares, allows to observe the liver perfusion in real time, becoming an useful and less invasive method to describe precisely the vascularization of hepatic lesions. This significantly increased the ability of US to detect and characterize focal liver lesions. The aim of this review article is to evaluate the role of contrast enhancement US in the diagnosis of hepatocellular carcinoma in cirrhotic liver, with reference to the guidelines of American Association for the Study of Liver Diseases, European Association for the Study of the Liver and European Federation of Societies for Ultrasound in Medicine and Biology.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51675506 and 51275504)the German Research Foundation(DFG)(Grant Nos.#ZA 422/5-1 and#ZA 422/6-1)
文摘A topology optimization method based on the solid isotropic material with penalization interpolation scheme is utilized for designing gradient coils for use in magnetic resonance microscopy. Unlike the popular stream function method, the proposed method has design variables that are the distribution of conductive material. A voltage-driven transverse gradient coil is proposed to be used as micro-scale magnetic resonance imaging（MRI） gradient coils, thus avoiding introducing a coil-winding pattern and simplifying the coil configuration. The proposed method avoids post-processing errors that occur when the continuous current density is approximated by discrete wires in the stream function approach. The feasibility and accuracy of the method are verified through designing the z-gradient and y-gradient coils on a cylindrical surface.Numerical design results show that the proposed method can provide a new coil layout in a compact design space.
文摘The development of second generation ultrasound (US) contrast-medium and specific imaging techniques with dedicated softwares, allows to observe the liver perfusion in real time, becoming an useful and less invasive method to describe precisely the vascularization of hepatic lesions. This significantly increased the ability of US to detect and characterize focal liver lesions. The aim of this review article is to evaluate the role of contrast enhancement US in the diagnosis of hepatocellular carcinoma in cirrhotic liver, with reference to the guidelines of American Association for the Study of Liver Diseases, European Association for the Study of the Liver and European Federation of Societies for Ultrasound in Medicine and Biology.
