Gutberlet Matthias, Noeske Ralph, Schwinge Kerstin, Freyhardt Patrick, Felix Roland, Niendorf Thoralf
Charité, Campus Virchow Klinikum, Universitätsmedizin Berlin, Klinik für Strahlenheilkunde, Diagnostic Radiology and Nuclear Medicine, Berlin, Germany.
Invest Radiol. 2006 Feb;41(2):154-67. doi: 10.1097/01.rli.0000195840.50230.10.
The objective of this study was to examine the applicability of high magnetic field strengths for comprehensive functional and structural cardiac magnetic resonance imaging (MRI).
Eighteen subjects underwent comprehensive cardiac MRI at 1.5 T and 3.0 T. The following imaging techniques were implemented: double and triple inversion prepared FSE for anatomic imaging, 4 different sets of echocardiographic-gated CINE strategies for functional and flow imaging, inversion prepared gradient echo for delayed enhancement imaging, T1-weighted segmented EPI for perfusion imaging and 2-dimensional (2-D) spiral, and volumetric SSFP for coronary artery imaging.
: Use of 3 Tesla as opposed to 1.5 Tesla provided substantial baseline signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) improvements for anatomic (T1-weighted double IR: DeltaSNR = 29%, DeltaCNR = 20%, T2-weighted double IR: DeltaSNR = 39%, DeltaCNR = 33%, triple IR: DeltaSNR = 74%, DeltaCNR = 60%), functional (conventional CINE: DeltaSNR = 123%, DeltaCNR = 74%, accelerated CINE: DeltaSNR = 161%, DeltaCNR = 86%), myocardial tagging (DeltaSNRsystole = 54%, DeltaCNRsystole = 176%), phase contrast flow measurements (DeltaSNR = 79%), viability (DeltaSNR = 48%, DeltaCNR = 40%), perfusion (DeltaSNR = 109%, DeltaCNR = 87%), and breathhold coronary imaging (2-D spiral: DeltaSNRRCA = 54%, DeltaCNRRCA = 69%, 3-D SSFP: DeltaSNRRCA = 60%, DeltaCNRRCA = 126%), but also revealed image quality issues, which were successfully tackled by adiabatic radiofrequency pulses and parallel imaging.
Cardiac MRI at 3.0 T is feasible for the comprehensive assessment of cardiac morphology and function, although SAR limitations and susceptibility effects remain a concern. The need for speed together with the SNR benefit at 3.0 T will motivate further advances in routine cardiac MRI while providing an image-quality advantage over imaging at 1.5 Tesla.
本研究的目的是探讨高磁场强度在心脏综合功能和结构磁共振成像（MRI）中的适用性。
18名受试者分别在1.5T和3.0T场强下接受心脏综合MRI检查。采用了以下成像技术：用于解剖成像的双反转和三反转准备快速自旋回波序列、用于功能和血流成像的4种不同的超声心动图门控电影序列策略、用于延迟强化成像的反转准备梯度回波序列、用于灌注成像的T1加权分段回波平面成像序列以及用于冠状动脉成像的二维（2-D）螺旋和容积稳态自由进动序列。
与1.5T相比，使用3T可显著提高解剖成像（T1加权双反转恢复序列：ΔSNR = 29%，ΔCNR = 20%；T2加权双反转恢复序列：ΔSNR = 39%，ΔCNR = 33%；三反转恢复序列：ΔSNR = 74%，ΔCNR = 60%）、功能成像（传统电影序列：ΔSNR = 123%，ΔCNR = 74%；加速电影序列：ΔSNR = 161%，ΔCNR = 86%）、心肌标记（收缩期ΔSNR = 54%，收缩期ΔCNR = 176%）、相位对比血流测量（ΔSNR = 79%）、心肌存活（ΔSNR = 48%，ΔCNR = 40%）、灌注成像（ΔSNR = 109%，ΔCNR = 87%）以及屏气冠状动脉成像（2-D螺旋序列：右冠状动脉ΔSNR = 54%，右冠状动脉ΔCNR = 69%；3-D稳态自由进动序列：右冠状动脉ΔSNR = 60%，右冠状动脉ΔCNR = 126%）的基线信噪比（SNR）和对比噪声比（CNR），但也发现了图像质量问题，通过绝热射频脉冲和平行成像成功解决。
3.0T心脏MRI对于心脏形态和功能的综合评估是可行的，尽管比吸收率（SAR）限制和磁化率效应仍然是需要关注的问题。3.0T场强下对速度的需求以及信噪比优势将推动常规心脏MRI的进一步发展，同时相对于1.5T成像具有图像质量优势。
