Optimized protocols for cardiac magnetic resonance imaging in patients with thoracic metallic implants.
Optimized protocols for cardiac magnetic resonance imaging in patients with thoracic metallic implants.
复制标题
胸部金属植入物患者心脏磁共振成像的优化方案。
DOI：
10.1007/s00247-015-3366-0
复制
发表时间：
2015
影响因子：
2.3
通讯作者：
Hansen,MichaelS
中科院分区：
文献类型：
--
作者：
Olivieri,LauraJ;Cross,RussellR;O'Brien,KendallE;Ratnayaka,Kanishka;Hansen,MichaelS
背景心脏磁共振（MR）成像在先天性心脏病中是一种有价值的工具，然而患者在治疗他们的疾病时经常在胸部有金属装置，这使得成像复杂化。需要方法来改善心脏附近金属植入物周围的成像。基本的序列参数操作有可能最大限度地减少伪影，同时限制对图像分辨率和质量的影响。我们的目标是设计电影和静态心脏成像序列，以最大限度地减少金属伪影，同时保持图像质量。我们开发了稳态自由旋进（SSFP）、梯度回波（GRE）电影成像和快速自旋回波（TSE）黑血成像的优化序列。我们对17名连续患者进行常规心脏MR成像，其中25个不同来源的金属植入物使用标准和优化的成像方案用于给定的切片位置。我们通过测量images.ResultsAll金属伪影在两个正交平面内的质量和金属伪影大小的图像进行评级金属伪影减少与优化成像。优化SSFP电影的平均金属伪影减少为1.5+/-1.8 mm，优化GRE电影的平均金属伪影减少为4.6+/-4.5 mm（P< 0.05）。质量评级有利于优化的GRE电影。同样，优化TSE图像的平均金属伪影减少为1.6+/-1.7 mm（P< 0.05），质量评级有利于优化TSE imaging.ConclusionImaging序列定制，以尽量减少金属伪影很容易通过修改基本序列参数创建，图像是上级优于标准成像序列的质量和伪影大小。具体而言，对于优化的电影成像，GRE序列应与有利于短回波时间的设置一起使用，即关闭流量补偿、弱非对称回波和相对较高的接收器带宽。对于静态黑血成像，应在关闭脂肪饱和和高接收器带宽的情况下使用TSE序列。
BackgroundCardiac magnetic resonance (MR) imaging is a valuable tool in congenital heart disease; however patients frequently have metal devices in the chest from the treatment of their disease that complicate imaging. Methods are needed to improve imaging around metal implants near the heart. Basic sequence parameter manipulations have the potential to minimize artifact while limiting effects on image resolution and quality.ObjectiveOur objective was to design cine and static cardiac imaging sequences to minimize metal artifact while maintaining image quality.Materials and methodsUsing systematic variation of standard imaging parameters on a fluid-filled phantom containing commonly used metal cardiac devices, we developed optimized sequences for steady-state free precession (SSFP), gradient recalled echo (GRE) cine imaging, and turbo spin-echo (TSE) black-blood imaging. We imaged 17 consecutive patients undergoing routine cardiac MR with 25 metal implants of various origins using both standard and optimized imaging protocols for a given slice position. We rated images for quality and metal artifact size by measuring metal artifact in two orthogonal planes within the image.ResultsAll metal artifacts were reduced with optimized imaging. The average metal artifact reduction for the optimized SSFP cine was 1.5+/−1.8 mm, and for the optimized GRE cine the reduction was 4.6+/−4.5 mm (P< 0.05). Quality ratings favored the optimized GRE cine. Similarly, the average metal artifact reduction for the optimized TSE images was 1.6+/−1.7 mm (P< 0.05), and quality ratings favored the optimized TSE imaging.ConclusionImaging sequences tailored to minimize metal artifact are easily created by modifying basic sequence parameters, and images are superior to standard imaging sequences in both quality and artifact size. Specifically, for optimized cine imaging a GRE sequence should be used with settings that favor short echo time, i.e. flow compensation off, weak asymmetrical echo and a relatively high receiver bandwidth. For static black-blood imaging, a TSE sequence should be used with fat saturation turned off and high receiver bandwidth.