Comparison of gadolinium-enhanced and ferumoxytol-enhanced conventional and UTE-MRA for the depiction of the pulmonary vasculature
Comparison of gadolinium-enhanced and ferumoxytol-enhanced conventional and UTE-MRA for the depiction of the pulmonary vasculature
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DOI：
10.1002/mrm.27853
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发表时间：
2019-11-01
影响因子：
3.3
通讯作者：
Nagle, Scott K.
中科院分区：
文献类型：
--
作者：
Knobloch, Gesine;Colgan, Timothy;Nagle, Scott K.
目的：方法：20例健康志愿者在3 T条件下进行2次增强肺MRA检查，间隔至少4周。访视1：在注射0.1 mmol/kg钆贝葡胺（GD）之前和之后，MRA开始于常规的多相3DT 1加权屏气扰相梯度回波MRA。随后，自由呼吸GD-UTE-MRA被采集为一系列3个翻转角（FA）（6度，12度，18度），以优化T-1加权。访视2：注射4 mg/kg FE后，在稳定状态下进行MRA，从传统的3D T-1加权屏气扰相梯度回波MRA开始，然后是自由呼吸FE-UTE-MRA，均在4个不同的FA（6度，12度，18度，24度）。评价了最佳T-1对比度的最佳FA。采用多相GD常规肺MRA（cMRA）作为参考标准，在4点顺序量表上比较了两种方法在最佳FA时的图像质量。结果：FE cMRA和两种UTE-MRA技术在18度-24度范围内的翻转角可获得最佳T1对比度（p > 0.05）。在优化FA时，FE-UTE-MRA和GD cMRA的血管图像质量良好/极佳（98% vs 97%; p = 0.51）。与GD增强或FE增强的cMRA相比，两种UTE技术对非血管结构的显示均具有上级优势（p < .001）。然而，GD-UTE-MRA显示了最低的图像质量的血管造影，由于低图像对比度。结论：自由呼吸UTE-MRA使用FE是可行的，同时评估肺血管和非血管结构。患者研究应调查自由呼吸UTE-MRA评估肺栓塞的临床效用。
Purpose: To evaluate the feasibility of ferumoxytol (FE)-enhanced UTE-MRA for depiction of the pulmonary vascular and nonvascular structures.Methods: Twenty healthy volunteers underwent contrast-enhanced pulmonary MRA at 3 T during 2 visits, separated by at least 4 weeks. Visit 1: The MRA started with a conventional multiphase 3D T1-weighted breath-held spoiled gradient-echo MRA before and after the injection of 0.1 mmol/kg gadobenate dimeglumine (GD). Subsequently, free-breathing GD-UTE-MRA was acquired as a series of 3 flip angles (FAs) (6 degrees, 12 degrees, 18 degrees) to optimize T-1 weighting. Visit 2: After the injection of 4 mg/kg FE, MRA was performed during the steady state, starting with a conventional 3D T-1-weighted breath-held spoiled gradient-echo MRA and followed by freebreathing FE-UTE-MRA, both at 4 different FAs (6 degrees, 12 degrees, 18 degrees, 24 degrees). The optimal FA for best T-1 contrast was evaluated. Image quality at the optimal FA was compared between methods on a 4-point ordinal scale, using multiphase GD conventional pulmonary MRA (cMRA) as standard of reference.Results: Flip angle in the range of 18 degrees-24 degrees resulted in best T1 contrast for FE cMRA and both UTE-MRA techniques (p > .05). At optimized FA, image quality of the vasculature was good/excellent with both FE-UTE-MRA and GD cMRA (98% versus 97%; p = .51). Both UTE techniques provided superior depiction of nonvascular structures compared with either GD-enhanced or FE-enhanced cMRA (p < .001). However, GD-UTE-MRA showed the lowest image quality of the angiogram due to low image contrast.Conclusion: Free-breathing UTE-MRA using FE is feasible for simultaneous assessment of the pulmonary vasculature and nonvascular structures. Patient studies should investigate the clinical utility of free-breathing UTE-MRA for assessment of pulmonary emboli.