全脑血管壁 MRI：提高三维可变翻转角涡轮自旋回波扫描效率的参数优化解决方案。
Whole-brain vessel wall MRI: A parameter tune-up solution to improve the scan efficiency of three-dimensional variable flip-angle turbo spin-echo.
机构信息
Department of Radiology, Xuanwu Hospital, Beijing, China.
Biomedical Imaging Research Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA.
出版信息
J Magn Reson Imaging. 2017 Sep;46(3):751-757. doi: 10.1002/jmri.25611. Epub 2017 Jan 20.
PURPOSE
To propose and evaluate a parameter tune-up solution to expedite a three-dimensional (3D) variable-flip-angle turbo spin-echo (TSE) sequence for whole-brain intracranial vessel wall (IVW) imaging.
MATERIALS AND METHODS
Elliptical k-space sampling and prolonged echo train length (ETL), were used to expedite a 3D variable-flip-angle TSE-based sequence. To compensate for the potential loss in vessel wall signal, optimal combination of prescribed T and ETL was experimentally investigated on 22 healthy volunteers at 3 Tesla. The optimized protocol (7-8 min) was then compared with a previous protocol (reference protocol, 11-12 min) in terms of signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), vessel wall sharpness, and wall delineation quality on a 4-point scale (0:poor; 3:excellent) in 10 healthy volunteers. A pilot study of five patients was performed and lesion delineation score was used to demonstrate the diagnostic quality.
RESULTS
A protocol with ETL = 52 and prescribed T = 170 ms was deemed an optimized one, which, compared with the reference protocol, provided significantly improved wall SNR (12.0 ± 1.3 versus 10.0 ± 1.1; P = 0.002), wall-lumen CNR (9.7 ± 1.2 versus 8.0 ± 0.9; P = 0.002), wall-CSF CNR (2.8 ± 1.0 versus 1.7 ± 1.0; P = 0.026), similar vessel wall sharpness at both inner (1.59 ± 0.18 versus 1.58 ± 0.14, P = 0.87) and outer (1.71 ± 0.25 versus 1.83 ± 0.30; P = 0.18) boundaries, and comparable vessel wall delineation score for individual segments (1.95-3; P > 0.06). In all patients, atherosclerotic plaques (10) or wall dissection (5) were identified with a delineation score of 3 or 2.
CONCLUSION
A parameter tune-up solution can accelerate 3D variable-flip-angle TSE acquisitions, particularly allowed for expedited whole-brain IVW imaging with preserved wall delineation quality.
LEVEL OF EVIDENCE
- Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:751-757.
目的
提出并评估一种参数调整解决方案，以加速三维（3D）可变翻转角涡轮自旋回波（TSE）序列进行全脑颅内血管壁（IVW）成像。
材料与方法
使用椭圆 K 空间采样和延长回波链长度（ETL）来加速基于 3D 可变翻转角 TSE 的序列。为了弥补血管壁信号的潜在损失，在 3T 下对 22 名健康志愿者进行了实验研究，以确定最佳的 T 和 ETL 规定组合。在 10 名健康志愿者中，将优化后的方案（7-8 分钟）与之前的方案（参考方案，11-12 分钟）在信噪比（SNR）、对比噪声比（CNR）、血管壁锐度以及血管壁描绘质量方面进行比较（0：差；3：优）。在 5 名患者中进行了一项初步研究，并使用病变描绘评分来证明诊断质量。
结果
确定 ETL=52 和规定 T=170ms 的方案为优化方案，与参考方案相比，该方案提供了显著改善的壁 SNR（12.0±1.3 与 10.0±1.1；P=0.002）、壁-腔 CNR（9.7±1.2 与 8.0±0.9；P=0.002）、壁-CSF CNR（2.8±1.0 与 1.7±1.0；P=0.026），在内外边界（1.59±0.18 与 1.58±0.14，P=0.87）上具有相似的血管壁锐度，并且各个节段的血管壁描绘评分相似（1.95-3；P>0.06）。在所有患者中，均可以识别出粥样斑块（10 个）或壁夹层（5 个），其描绘评分为 3 或 2。
结论
参数调整解决方案可以加速 3D 可变翻转角 TSE 采集，特别是允许加速全脑 IVW 成像并保持壁描绘质量。
证据水平
- 技术功效：第 1 阶段 J. MAGN. RESON. IMAGING 2017；46:751-757.
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