Flow-sensitive 4D MRI of the thoracic aorta: Comparison of image quality, quantitative flow, and wall parameters at 1.5 T and 3 T
Flow-sensitive 4D MRI of the thoracic aorta: Comparison of image quality, quantitative flow, and wall parameters at 1.5 T and 3 T
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DOI：
10.1002/jmri.23735
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发表时间：
2012-11-01
影响因子：
4.4
通讯作者：
Markl, Michael
中科院分区：
文献类型：
--
作者：
Strecker, Christoph;Harloff, Andreas;Markl, Michael
目的：评价磁场强度对胸主动脉血流敏感4D磁共振成像(MRI)的影响。在1.5T和3T下进行志愿者研究，比较相位对比磁共振血管成像(MRA)和3D血流显示质量以及主动脉血流动力学的量化。材料和方法：对10名健康志愿者分别进行1.5T和3T流量敏感的4DMRI扫描，成像参数相同(TE/TR=6/5.1毫秒，空间/时间分辨率接近2 mm/40.8毫秒)。分析包括评估衍生的主动脉3D相位对比(PC)血管成像和3D血流显示(按02标准进行半定量分级，两名盲人)，以及血流速度、每个心动周期的净流量、壁切应力(WSS)和速度噪声的量化。结果：3T时3D血流显示质量(3T时平均分级为1.8+/-0.4，1.5T时为1.1+/-0.7)和3D PC-MRA对主动脉腔几何形态的描述(1.7+/-0.5vs.1.2+/-0.6)在3T时显著改善(P<；0.01)，而速度噪声显著升高(P<；在1.5T时，流速量化的结果与3T相比变化最小(0.05m/S、3mL/周期和0.01N/m2)，但无统计学差异(P=0.40、P=0.39和P=0.82)。结论：在3T时，血流敏感的4DMRI可改善图像质量，且不增加与高场相关的伪影。1.5T磁共振成像也是可行的，它提供了中等质量的主动脉三维血流动力学信息，在定量分析方面具有相同的性能。J·马根。雷森。《成像》2012年；36：10971103。(C)2012年威利期刊公司。
Purpose: To evaluate the effect of field strength on flow-sensitive 4D magnetic resonance imaging (MRI) of the thoracic aorta. A volunteer study at 1.5 T and 3 T was conducted to compare phase-contrast MR angiography (MRA) and 3D flow visualization quality as well as quantification of aortic hemodynamics. Materials and Methods: Ten healthy volunteers were examined by flow-sensitive 4D MRI at both 1.5 T and 3 T MRI with identical imaging parameters (TE/TR = 6/5.1 msec, spatial/temporal resolution approximate to 2 mm/40.8 msec). Analysis included assessment of image quality of derived aortic 3D phase contrast (PC) angiography and 3D flow visualization (semiquantitative grading on a 02 scale, two blinded observers) and quantification of blood flow velocities, net flow per cardiac cycle, wall shear stress (WSS), and velocity noise. Results: Quality of 3D blood flow visualization (average grading = 1.8 +/- 0.4 at 3 T vs. 1.1 +/- 0.7 at 1.5 T) and the depiction of aortic lumen geometry by 3D PC-MRA (1.7 +/- 0.5 vs. 1.2 +/- 0.6) were significantly (P < 0.01) improved at 3 T while velocity noise was significantly higher (P < 0.01) at 1.5 T. Velocity quantification resulted in minimally altered (0.05 m/s, 3 mL/cycle and 0.01 N/m2) but not statistically different (P = 0.40, P = 0.39, and P = 0.82) systolic peak velocities, net flow, and WSS for 1.5 T compared to 3 T. Conclusion: Flow-sensitive 4D MRI at 3 T provided improved image quality without additional artifacts related to higher fields. Imaging at 1.5 T MRI, which is more widely available, was also feasible and provided information on aortic 3D hemodynamics of moderate quality with identical performance regarding quantitative analysis. J. Magn. Reson. Imaging 2012;36:10971103. (c) 2012 Wiley Periodicals, Inc.