Can a single-shot black-blood T2-weighted spin-echo echo-planar imaging sequence with sensitivity encoding replace the respiratory-triggered turbo spin-echo sequence for the liver? An optimization and feasibility study
Can a single-shot black-blood T2-weighted spin-echo echo-planar imaging sequence with sensitivity encoding replace the respiratory-triggered turbo spin-echo sequence for the liver? An optimization and feasibility study
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DOI：
10.1002/jmri.20269
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发表时间：
2005-03-01
影响因子：
4.4
通讯作者：
Wielopolski, PA
中科院分区：
文献类型：
--
作者：
Hussain, SM;De Becker, J;Wielopolski, PA
目的：为了优化和评估一个单次激发的黑血T2加权自旋回波平面成像（SSBB-EPI）序列的可行性，使用灵敏度编码（SENSE）的肝脏MRI，并比较与T2加权涡轮自旋回波序列（USE）sequence.Materials和方法：6名志愿者和16例患者进行扫描在1.5T（Philips Intera）。在志愿者研究中，我们优化了。SSBB-EPI序列通过交互式地改变参数（即，分辨率、回波时间（TE）、具有低b值的扩散加权以及相位编码梯度的极性）。评估了每项变更的影响。对16例患者应用优化的SSBB-EPI序列。包括整体图像质量（1-5级）在内的多个项目用于分级评价。此外，还计算了肝脏的信噪比（SNR）。采用Wilcoxons符号秩检验进行统计学分析，比较SSBB-EPI和TSE序列，P 0.05被认为是显着性的限制。结果：SSBB-EPI序列通过以下步骤进行改进：1）频率点比相位编码步骤少，2）b因子为20，3）相位编码梯度的极性相反。在患者中，优化SSBB-EPI的平均总体图像质量评分（3.5（范围：1- 4））和TSE（3.6（范围：3- 4）），以及SSBB-EPI上肝脏的SNR（平均值+/- SD = 7.6 +/- 4.0）和TSE（8.9 +/- 4.6）无显著差异（P >.05）。结论：经证明，使用SENSE优化的SSBB-EPI在患者中是可行的，肝脏的整体图像质量和SNR与标准的经颅触发T2加权TSE序列相当。
Purpose: To optimize and assess the feasibility of a single-shot black-blood T2-weighted spin-echo echo-planar imaging (SSBB-EPI) sequence for MRI of the liver using sensitivity encoding (SENSE), and compare the results with those obtained with a T2-weighted turbo spin-echo USE) sequence.Materials and Methods: Six volunteers and 16 patients were scanned at 1.5T (Philips Intera). In the volunteer study, we optimized the. SSBB-EPI sequence by interactively changing the parameters (i.e., the resolution, echo time (TE), diffusion weighting with low b-values, and polarity of the phase-encoding gradient) with regard to distortion, suppression of the blood signal, and sensitivity to motion. The influence of each change was assessed. The optimized SSBB-EPI sequence was applied in patients (N = 16). A number of items, including the overall image quality (on a scale of 1-5), were used for graded evaluation. In addition, the signal-to-noise ratio (SNR) of the liver was calculated. Statistical analysis was carried out with the use of Wilcoxons signed rank test for comparison of the SSBB-EPI and TSE sequences, with P 0.05 considered the limit for significance.Results: The SSBB-EPI sequence was improved by the following steps: 1) less frequency points than phase-encoding steps, 2) a b-factor of 20, and 3) a reversed polarity of the phase-encoding gradient. In patients, the mean overall image quality score for the optimized SSBB-EPI (3.5 (range: 1- 4)) and TSE (3.6 (range: 3- 4)), and the SNR of the liver on SSBB-EPI (mean +/- SD = 7.6 +/- 4.0) and TSE (8.9 +/- 4.6) were not significantly different (P >.05).Conclusion: Optimized SSBB-EPI with SENSE proved to be feasible in patients, and the overall image quality and SNR of the liver were comparable to those achieved with the standard respiratory-triggered T2-weighted TSE sequence.