Effects of Contrast Agent on Water Suppression and Shimming of Kidney Single-Volume Proton MR Spectroscopy at 3.0T
Effects of Contrast Agent on Water Suppression and Shimming of Kidney Single-Volume Proton MR Spectroscopy at 3.0T
复制标题
造影剂对3.0T肾脏单体积质子磁共振波谱水抑制和匀场的影响
DOI：
10.1016/j.acra.2010.07.005
复制
发表时间：
2010-12-01
影响因子：
4.8
通讯作者：
Xiao, Yuan-Qiu
中科院分区：
文献类型：
--
作者：
Xu, Li;Liang, Chang-Hong;Xiao, Yuan-Qiu
基本原理和目标：本研究的目的是确定钆二乙烯三胺五乙酸（Gd-DTPA）的给药是否显著影响肾脏磁共振光谱预扫描的匀场和水抑制，以及在3.0-T系统上静脉给药后匀场和水抑制的影响是否随时间变化。在给予Gd-DTPA之前和之后检查了40名患者（2名患者因运动而被排除在分析之外）（右肾和左肾之间的间隔约为40秒）。将感兴趣区域分别仔细定位在双肾相应位置的区域中。获得了线宽（半峰全宽）和水抑制。使用配对t检验比较平均值。此外，在5名患者的右肾相同感兴趣区域中，以较短的时间间隔（注射后120-130秒获得）和较长的时间间隔（注射后150-160秒获得）进行重复测量。1例患者在同一感兴趣区域进行了连续H-1磁共振波谱预扫描。结果：注射造影剂后，左肾的匀场和水抑制效果略好于右肾（P均<0.01）。在两个肾脏的增强图像上，匀场和水抑制效应的极限分辨率均降低（所有P值均< .01）。较长时间间隔组的匀场和水抑制效果优于较短时间间隔组（所有P值均< .01）。1例患者注射Gd-DTPA后，检查前右肾和左肾的匀场和水抑制的顺序值分别为13 Hz和97%和12 Hz和97%，5分钟时为34 Hz和86%和30 Hz和88%，10分钟时为32 Hz和89%和27 Hz和90%，结论：注射Gd-DTPA后，水抑制和匀场效应均出现不良反应，且随着时间的延长，水抑制和匀场效应均呈现逐渐恢复的趋势。这种现象限制了对比增强磁共振成像后立即进行的肾脏磁共振波谱的诊断用途。
Rationale and Objectives: The aim of this study was to determine whether the administration of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) significantly affects shimming and water suppression on kidney magnetic resonance spectroscopic prescanning and whether the impact of shimming and water suppression is changed with time after intravenous administration on a 3.0-T system.Methods: Forty patients (two patients were excluded from analysis because of motion) were examined before and after the administration of Gd-DTPA (the interval between the right and left kidneys was approximately 40 seconds). Regions of interest were carefully positioned in the region of the corresponding location of both kidneys separately. Line widths (full width at half maximum) and water suppression were obtained. A paired t test for comparison of means was used. In addition, repeat measurements with a shorter time interval (obtained 120-130 seconds after the injection) and a longer time interval (obtained 150-160 seconds after the injection) were performed in five patients in the same regions of interest of the right kidney. Sequential H-1 magnetic resonance spectroscopic prescanning in the same region of interest was performed in one patient.Results: The left kidney had slightly better shimming and water suppression effects than the right kidney after contrast agent administration (all P values < .01). The limiting resolution of both shimming and water suppression effects was decreased on enhanced images in both kidneys (all P values < .01). The longer time interval group had better shimming and water suppression effects than the shorter time interval group (all P values < .01). After the administration of Gd-DTPA in one patient, sequential values of shimming and water suppression in the right and left kidneys, respectively, were 13 Hz and 97% and 12 Hz and 97% prior to the examination, 34 Hz and 86% and 30 Hz and 88% at 5 minutes, 32 Hz and 89% and 27 Hz and 90% at 10 minutes, 28 Hz and 91% and 24 Hz and 91% at 15 minutes, and 24 Hz and 92% and 20 Hz and 92% at 25 minutes.Conclusions: Gd-DTPA exerts adverse effects on water suppression and shimming, both of which show a trend of becoming well gradually with time extension after the injection of Gd-DTPA. This phenomenon limits the diagnostic use of kidney magnetic resonance spectroscopy performed immediately after contrast-enhanced magnetic resonance imaging.