公开(公告)号：US20150212174A1

公开(公告)日：2015-07-30

申请号：US14685021

申请日：2015-04-13

申请人： Case Western Reserve University

发明人： Robert W. Brown ,  Yong Wu ,  Zhen Yao ,  Shmaryu Shvartsman ,  Thomas Chmielewski ,  Timothy Eagan

IPC分类号： G01R33/422 ,  G01R33/48 ,  G01R33/385 ,  G01R33/565 ,  G01R33/341

CPC分类号： G01R33/422 ,  G01R33/341 ,  G01R33/385 ,  G01R33/4822 ,  G01R33/56518 ,  Y10T83/505

摘要： Radio frequency (RF) shields used with magnetic resonance imaging (MRI) apparatus may experience gradient field induced eddy currents and RF field induced eddy currents. These eddy currents can cause the RF shield to heat up at an undesirable rate. RF shields are designed to have a desired degree of RF shielding and a desired heating attribute. Design goals for RF shields include gradient field transparency and RF field opacity, both of which can be influenced by eddy currents. Example methods identify a gradient field that will induce eddy currents and identify an RF field that will induce eddy currents. If a region on the RF shield is identified where the desired heating attribute will not be achieved, then a pattern of axial cuts and azimuthal cuts can be made in the RF shield to reduce gradient eddy current heating in the RF shield while maintaining desired RF shielding.

摘要翻译： 与磁共振成像（MRI）装置一起使用的射频（RF）屏蔽可能会经历梯度场感应涡流和射频场感应涡流。 这些涡流可以使RF屏蔽以不期望的速率加热。 RF屏蔽被设计为具有期望的RF屏蔽程度和期望的加热属性。 RF屏蔽的设计目标包括梯度场透明度和RF场不透明度，这两者都可以受涡流影响。 示例性方法识别将引起涡流的梯度场，并识别将产生涡流的RF场。 如果RF屏蔽上的区域被识别出将不能实现所需的加热属性，则可以在RF屏蔽中进行轴向切割和方位切割的图案，以减少RF屏蔽中的梯度涡流加热，同时保持所需的RF屏蔽 。

公开(公告)号：US10557902B2

公开(公告)日：2020-02-11

申请号：US14685021

申请日：2015-04-13

申请人： Case Western Reserve University

发明人： Robert W. Brown ,  Yong Wu ,  Zhen Yao ,  Shmaryu Shvartsman ,  Thomas Chmielewski ,  Timothy Eagan

IPC分类号： G01V3/00 ,  G01R33/422 ,  G01R33/565 ,  G01R33/341 ,  G01R33/385 ,  G01R33/48

摘要： Radio frequency (RF) shields used with magnetic resonance imaging (MRI) apparatus may experience gradient field induced eddy currents and RF field induced eddy currents. These eddy currents can cause the RF shield to heat up at an undesirable rate. RF shields are designed to have a desired degree of RF shielding and a desired heating attribute. Design goals for RF shields include gradient field transparency and RF field opacity, both of which can be influenced by eddy currents. Example methods identify a gradient field that will induce eddy currents and identify an RF field that will induce eddy currents. If a region on the RF shield is identified where the desired heating attribute will not be achieved, then a pattern of axial cuts and azimuthal cuts can be made in the RF shield to reduce gradient eddy current heating in the RF shield while maintaining desired RF shielding.