Accelerated, free-breathing, noncontrast, electrocardiograph-triggered, thoracic MR angiography with stack-of-stars k-space sampling and GRASP reconstruction
Accelerated, free-breathing, noncontrast, electrocardiograph-triggered, thoracic MR angiography with stack-of-stars k-space sampling and GRASP reconstruction
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DOI：
10.1002/mrm.27409
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发表时间：
2019-01-01
影响因子：
3.3
通讯作者：
Kim, Daniel
中科院分区：
文献类型：
--
作者：
Haji-Valizadeh, Hassan;Collins, Jeremy D.;Kim, Daniel
目的：开发一种加速、自由呼吸、无对比、心电图触发的胸部MR血管造影（NC-MRA）脉冲序列，能够在临床可接受的扫描时间内实现高空间分辨率，并测试它是否能在疑似主动脉疾病患者中产生临床可接受的图像质量。方法：对“冠状动脉”MRA脉冲序列进行改进，采用叠星k空间采样模式，并结合金角径向稀疏平行（GRASP）重构，实现呼吸运动的自导航和高数据加速。在13例患者中评估了拟议的NC-MRA的性能，其中使用临床标准对比增强MRA （CE-MRA）作为对照。为了进行视觉分析，两位读者以5分制对血管腔、伪影和噪音水平的显著性进行了评分（总分指数=三个分数的总和）。在7个标准化位置测量主动脉直径。使用适当的统计检验比较平均视觉评分、观察者间变异性和血管直径。结果：总体平均视觉评分指数（CE-MRA为12.1 +/- 1.7，NC-MRA为12.1 +/- 1.0）评分无显著差异（P < 0.16）。两种阅读者在CE-MRA上的得分差异有统计学意义（P = 0.01），在NC-MRA上无统计学意义（P = 0.21）。除主动脉弓近端外，两组平均血管直径差异无统计学意义（P < 0.03）。平均直径相关性强（R-2 >= 0.96），且一致性好（绝对平均差）
Purpose: To develop an accelerated, free-breathing, noncontrast, electrocardiograph-triggered, thoracic MR angiography (NC-MRA) pulse sequence capable of achieving high spatial resolution at clinically acceptable scan time and test whether it produces clinically acceptable image quality in patients with suspected aortic disease.Methods: We modified a "coronary" MRA pulse sequence to use a stack-of-stars k-space sampling pattern and combined it with golden-angle radial sparse parallel (GRASP reconstruction to enable self-navigation of respiratory motion and high data acceleration. The performance of the proposed NC-MRA was evaluated in 13 patients, where clinical standard contrast-enhanced MRA (CE-MRA) was used as control. For visual analysis, two readers graded the conspicuity of vessel lumen, artifacts, and noise level on a 5-point scale (overall score index = sum of three scores). The aortic diameters were measured at seven standardized locations. The mean visual scores, inter-observer variability, and vessel diameters were compared using appropriate statistical tests.Results: The overall mean visual score index (12.1 +/- 1.7 for CE-MRA versus 12.1 +/- 1.0 for NC-MRA) scores were not significantly different (P > 0.16). The two readers' scores were significantly different for CE-MRA (P = 0.01) but not for NC-MRA (P = 0.21). The mean vessel diameters were not significantly different, except at the proximal aortic arch (P < 0.03). The mean diameters were strongly correlated (R-2 >= 0.96) and in good agreement (absolute mean difference