ToF-SWI: Simultaneous Time of Flight and Fully Flow Compensated Susceptibility Weighted Imaging
ToF-SWI: Simultaneous Time of Flight and Fully Flow Compensated Susceptibility Weighted Imaging
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DOI：
10.1002/jmri.21673
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发表时间：
2009-06-01
影响因子：
4.4
通讯作者：
Reichenbach, Juergen R.
中科院分区：
文献类型：
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作者：
Deistung, Andreas;Dittrich, Enrico;Reichenbach, Juergen R.
目的：对双回波序列（ToF-SWI）用于三维飞行时间（ToF）血管造影和敏感性加权成像（SWI）的参数选择进行系统研究。材料和方法：在1.5 T和3 T MR扫描仪上实现ToF-SW，并对第二次回波进行完整的3D一阶流补偿。基于幻体和体内实验，研究了现在补偿SWI回波的效率。在志愿者中检查动脉和静脉对比作为翻转角度的函数，并与额外获得的单回波ToF和单回波SWI数据进行比较。结果：为了减少信号空洞引起的SWI部分动脉污染，需要完全的血流补偿。20度的倾斜角度最能描绘动脉。静脉对比。被保存了下来。将ToF- swi与单回波ToF进行比较，显示动脉质量相似，并能很好地描绘所有主要动脉。与单回波SWI采集相比，ToF-SWI使用的薄片较薄，信噪比较低，从而降低了静脉圈定。结论：双回波序列（ToF-SWI）在单次扫描中对第二回波进行全流量补偿是可行的。该序列允许同时显示内在共配的动脉和静脉，而不会因斜流而导致血管的空间错配，并且动脉信号损失最小。
Purpose: To perform systematic investigations on parameter selection of a dual-echo sequence (ToF-SWI) for combined 3D time-of-flight (ToF) angiography and susceptibility weighted imaging (SWI).Materials and Methods: ToF-SW was implemented on 1.5 T and 3 T MR scanners with complete 3D first-order flow compensation of the second echo. The efficiency of now compensating the SWI echo was studied based on phantom and in vivo examinations. Arterial and venous contrasts were examined in volunteers as a function of flip angle and compared with additionally acquired single-echo ToF and single-echo SWI data.Results: Complete flow compensation is required to reduce arterial contamination in the SWI part caused by signal voids. A ramped flip angle of 20 degrees depicted arteries best. while venous contrast. was preserved. Comparing ToF-SWI with single-echo ToF demonstrated arteries with similar quality and delineated all major arteries equally well. Venous delineation was degraded due to lower SNR associated with the thinner slabs used with ToF-SWI compared to single-echo SWI acquisition.Conclusion: A dual-echo sequence (ToF-SWI) with full flow compensation of the second echo in a single scan is feasible. This sequence allows simultaneous visualization of intrinsically coregistered arteries and veins without spatial mis-registration of vessels caused by oblique flow and with minimal signal loss in arteries.