公开(公告)号：US20060145699A1

公开(公告)日：2006-07-06

申请号：US10544513

申请日：2004-01-29

申请人： Cornelis Ham ,  Wilhelmus Mens ,  Johannes Groen

发明人： Cornelis Ham ,  Wilhelmus Mens ,  Johannes Groen

IPC分类号： G01V3/00

CPC分类号： G01R33/3854

摘要： The invention relates to a magnetic resonance imaging (MRI) system comprising an examination volume (9), a main magnet system (17) for generating a main magnetic field (Bo) in the examination volume, a gradient magnet system (25) for generating gradients of the main magnetic field, and a control system (37) for compensating disturbances of the magnetic field caused by mechanical vibrations of the MRI system. According to the invention, the control system is a feed-forward control system which determines a necessary compensation for said disturbances in dependence on an electric current in the gradient magnet system according to a predetermined response relation. Since in most MRI systems the mechanical vibrations are predominantly caused by the altering electric currents in the gradient magnet system and by eddy currents induced thereby, the invention provides an accurate and reliable compensation for said disturbances, so that artifacts and other distortions of the reconstructed image caused by said disturbances are considerably reduced.

摘要翻译： 本发明涉及一种磁共振成像（MRI）系统，其包括检查体积（9），用于在检查体积中产生主磁场（B ）的主磁体系统（17）， 梯形磁体系统（25），用于产生主磁场的梯度;以及控制系统（37），用于补偿由MRI系统的机械振动引起的磁场的扰动。 根据本发明，控制系统是前馈控制系统，其根据预定的响应关系，根据梯度磁铁系统中的电流来确定对所述干扰的必要补偿。 由于在大多数MRI系统中，机械振动主要是由梯度磁体系统中的改变电流和由此引起的涡流引起的，本发明为所述扰动提供了精确和可靠的补偿，从而使得重构图像的伪像和其它失真 所造成的干扰大大减少。

公开(公告)号：US20060197525A1

公开(公告)日：2006-09-07

申请号：US10553327

申请日：2004-04-05

申请人： Wilhelmus Mens

发明人： Wilhelmus Mens

IPC分类号： G01V3/00

CPC分类号： G01R33/565

摘要： A magnetic resonance imaging system comprises reconstruction unit that is arranged to reconstruct a complex image of complex valued pixels from magnetic resonance signals. A compute a distribution of phase values of the complex image and to apply a phase correction to the complex image to form a corrected magnetic resonance image. The phase correction is controlled on the basis of the distribution of phase values of the complex image. Notably, the histogram power function is an effective indicator of the accuracy of the phase correction.

摘要翻译： 磁共振成像系统包括重建单元，其被配置为从磁共振信号重构复数像素的复数图像。 A计算复数图像的相位值分布，并对复像进行相位校正以形成校正的磁共振图像。 基于复数图像的相位值的分布来控制相位校正。 值得注意的是，直方图功率函数是相位校正精度的有效指标。