Eddy current-nulled convex optimized diffusion encoding (EN-CODE) for distortion-free diffusion tensor imaging with short echo times
Eddy current-nulled convex optimized diffusion encoding (EN-CODE) for distortion-free diffusion tensor imaging with short echo times
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DOI：
10.1002/mrm.26709
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发表时间：
2018-02-01
影响因子：
3.3
通讯作者：
Ennis, Daniel B.
中科院分区：
文献类型：
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作者：
Aliotta, Eric;Moulin, Kevin;Ennis, Daniel B.
目的设计和评价涡流归零凸优化扩散编码(EN-CODE)梯度波形，以实现有效的无涡流引起图像失真的扩散张量成像(DTI)。在回波时间(TE)和图像失真方面，将编码的DTI波形与现有的涡流置零二次重聚焦自旋回波(TRSE)序列以及单极(Mono)和非涡流补偿的编码进行了比较。对10名健康志愿者进行了模拟、体模实验和神经成像的比较。结果编码序列实现了涡流补偿，其TE明显短于TRSE(78ms比96ms)，比Mono序列略短(78ms比80ms)。体素内信号方差在编码模组中低于单编码模组(13.611.6比37.4+/-25.8)，与TRSE无差异(15.1+/-11.6)，表明对涡流引起的图像失真具有良好的稳健性。脑部边缘的平均分数各向异性值编码也显著低于单声学编码(0.16+/-0.01比0.24+/-0.02，P
PurposeTo design and evaluate eddy current-nulled convex optimized diffusion encoding (EN-CODE) gradient waveforms for efficient diffusion tensor imaging (DTI) that is free of eddy current-induced image distortions.MethodsThe EN-CODE framework was used to generate diffusion-encoding waveforms that are eddy current-compensated. The EN-CODE DTI waveform was compared with the existing eddy current-nulled twice refocused spin echo (TRSE) sequence as well as monopolar (MONO) and non-eddy current-compensated CODE in terms of echo time (TE) and image distortions. Comparisons were made in simulations, phantom experiments, and neuro imaging in 10 healthy volunteers.ResultsThe EN-CODE sequence achieved eddy current compensation with a significantly shorter TE than TRSE (78 versus 96 ms) and a slightly shorter TE than MONO (78 versus 80 ms). Intravoxel signal variance was lower in phantoms with EN-CODE than with MONO (13.611.6 versus 37.4 +/- 25.8) and not different from TRSE (15.1 +/- 11.6), indicating good robustness to eddy current-induced image distortions. Mean fractional anisotropy values in brain edges were also significantly lower with EN-CODE than with MONO (0.16 +/- 0.01 versus 0.24 +/- 0.02, P