Superelliptical insert gradient coil with a field-modifying layer for breast imaging.
Superelliptical insert gradient coil with a field-modifying layer for breast imaging.
复制标题
具有用于乳腺成像的场修改层的超椭圆插入梯度线圈。
DOI：
10.1002/mrm.22639
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发表时间：
2011
影响因子：
3.3
通讯作者：
Parker,DennisL
中科院分区：
文献类型：
--
作者：
Moon,SungM;Goodrich,KCraig;Hadley,JRock;Kim,Seong-Eun;Zeng,GengshengL;Morrell,GlenR;McAlpine,MatthewA;Chronik,BlaineA;Parker,DennisL
许多MRI应用，例如乳腺的动态增强MRI，需要高的空间和时间分辨率，并且可以受益于改进的梯度性能，例如，增加的梯度强度和减少的梯度上升时间。可以通过使用专门为目标解剖设计的局部插入梯度来实现实现该应用的高空间和时间分辨率所需的改进的梯度性能。目前的平面梯度系统不能产生足够大的成像体积来容纳两个乳房；此外，它们的梯度场不均匀，随着距离梯度线圈表面的距离而迅速下降。为了获得适合双侧乳腺MRI的成像体积，平面局部梯度系统设计被修改为超椭圆形状，产生的均匀梯度体积比相应的标准平面梯度(左/右方向)宽182%(Gx)、57%(Gy)和75%(Gz)。增加一个附加的场修正梯度绕组，导致梯度线圈表面附近的均匀梯度场比已经扩大的超椭圆梯度的均匀梯度体积(分别为Gx、Gy和Gz的67%、89%和214%)有额外的改善。建立了一个原型梯度插入器，展示了超椭圆梯度在3T磁共振成像系统中的成像和实现特性。Magn Reson Med，2011。©2010 Wiley-Liss公司。
Many MRI applications such as dynamic contrast‐enhanced MRI of the breast require high spatial and temporal resolution and can benefit from improved gradient performance, e.g., increased gradient strength and reduced gradient rise time. The improved gradient performance required to achieve high spatial and temporal resolution for this application may be achieved by using local insert gradients specifically designed for a target anatomy. Current flat gradient systems cannot create an imaging volume large enough to accommodate both breasts; further, their gradient fields are not homogeneous, dropping off rapidly with distance from the gradient coil surface. To attain an imaging volume adequate for bilateral breast MRI, a planar local gradient system design has been modified into a superellipse shape, creating homogeneous gradient volumes that are 182% (Gx), 57% (Gy), and 75% (Gz) wider (left/right direction) than those of the corresponding standard planar gradient. Adding an additional field‐modifying gradient winding results in an additional improvement of the homogeneous gradient field near the gradient coil surface over the already enlarged homogeneous gradient volumes of the superelliptical gradients (67%, 89%, and 214% forGx,Gy, andGzrespectively). A prototypey‐gradient insert has been built to demonstrate imaging and implementation characteristics of the superellipse gradient in a 3 T MRI system. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.