T1 mapping performance and measurement repeatability: results from the multi-national T1 mapping standardization phantom program (T1MES)
T1 mapping performance and measurement repeatability: results from the multi-national T1 mapping standardization phantom program (T1MES)
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DOI：
10.1186/s12968-020-00613-3
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发表时间：
2020-05-07
影响因子：
6.4
通讯作者：
Moon, James C.
中科院分区：
文献类型：
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作者：
Captur, Gabriella;Bhandari, Abhiyan;Moon, James C.
背景T-1标测和细胞外容积（ECV）标准化（T1 MES）项目使用经美国食品药品监督管理局（FDA）和欧洲合格认证组织（CE）监管批准的专用体模探索了T-1标测质量保证。我们报告了各中心的T-1测量重复性，描述了序列、磁体和供应商性能。方法对2015年8月批量生产的骨水泥进行了2年的结构成像、B-0和B-1以及“参考”慢T-1检测。温度依赖性由美国国家标准与技术研究所和德国联邦物理技术研究所评估。使用多个T-1标测序列，在34个1.5 T和22个3 T磁体上评估了平均358天（最多1161天）的中心特定T-1标测重复性（每周最多一次扫描，每季度最少一次扫描）。半自动分析图像和温度数据。根据变异系数（CoV）评价了系列T-1的重复性，并构建了线性混合模型以研究一些已知T-1变异来源的相互作用。结果2年后，体模凝胶完整性保持完好（无撕裂/撕裂），B-0和B-1均匀，“参考”T-1与基线相比稳定（1.5 T时的%变化，1.95 +/- 1.39%; 3 T时，2.22 +/- 1.44%）。每摄氏度，1.5 T，T-1（MOLLI 5s（3s）3s）在长的自体血管中增加11.4 ms，在短的造影后心肌管中减少1.2 ms。在两种场强下，Siemens和Philips CMR系统的估计T-1时间与“参考”T-1的一致性相似（两种场强的调整R-2范围为0.99-1.00）。在1年内，许多1.5 T和3 T序列/磁体可重复，平均CoV分别< 1和2%。1.5 T的重复性较3 T窄。在T1 MES内，对于几个序列，天然T-1的重复性较窄，例如，在1.5 T下，Siemens MOLLI 5s（3s）3s原型编号448 B（平均CoV = 0.27%）和Philips改良的Look-Rolling反转恢复（MOLLI）3s（3s）5s（CoV 0.54%），以及在3 T时，Philips MOLLI 3b（3s）5 b（CoV 0.33%）和Siemens缩短型MOLLI（ShMOLLI）原型780 C（CoV 0.69%）。调整温度和场强后，发现T-1标测序列和扫描仪软件版本（1.5 T和3 T时均P < 0.001）以及较小程度上的扫描仪型号（P = 0.011，仅1.5 T）对多个中心的T-1影响最大。结论T1 MES CE/FDA批准的体模是一种可靠的质量保证器械。在多中心环境中，T-1标测在场强、序列、扫描仪软件版本和制造商之间存在性能差异。然而，场强、序列和扫描仪的几种特定组合具有高度可重复性，因此，有可能为临床使用提供T-1时间的标准化评估，尽管至少需要对原生T-1管进行温度校正。
Background The T-1 Mapping and Extracellular volume (ECV) Standardization (T1MES) program explored T-1 mapping quality assurance using a purpose-developed phantom with Food and Drug Administration (FDA) and Conformite Europeenne (CE) regulatory clearance. We report T-1 measurement repeatability across centers describing sequence, magnet, and vendor performance. Methods Phantoms batch-manufactured in August 2015 underwent 2 years of structural imaging, B-0 and B-1, and "reference" slow T-1 testing. Temperature dependency was evaluated by the United States National Institute of Standards and Technology and by the German Physikalisch-Technische Bundesanstalt. Center-specific T-1 mapping repeatability (maximum one scan per week to minimum one per quarter year) was assessed over mean 358 (maximum 1161) days on 34 1.5 T and 22 3 T magnets using multiple T-1 mapping sequences. Image and temperature data were analyzed semi-automatically. Repeatability of serial T-1 was evaluated in terms of coefficient of variation (CoV), and linear mixed models were constructed to study the interplay of some of the known sources of T-1 variation. Results Over 2 years, phantom gel integrity remained intact (no rips/tears), B-0 and B-1 homogenous, and "reference" T-1 stable compared to baseline (% change at 1.5 T, 1.95 +/- 1.39%; 3 T, 2.22 +/- 1.44%). Per degrees Celsius, 1.5 T, T-1 (MOLLI 5s(3s)3s) increased by 11.4 ms in long native blood tubes and decreased by 1.2 ms in short post-contrast myocardium tubes. Agreement of estimated T-1 times with "reference" T-1 was similar across Siemens and Philips CMR systems at both field strengths (adjusted R-2 ranges for both field strengths, 0.99-1.00). Over 1 year, many 1.5 T and 3 T sequences/magnets were repeatable with mean CoVs < 1 and 2% respectively. Repeatability was narrower for 1.5 T over 3 T. Within T1MES repeatability for native T-1 was narrow for several sequences, for example, at 1.5 T, Siemens MOLLI 5s(3s)3s prototype number 448B (mean CoV = 0.27%) and Philips modified Look-Locker inversion recovery (MOLLI) 3s(3s)5s (CoV 0.54%), and at 3 T, Philips MOLLI 3b(3s)5b (CoV 0.33%) and Siemens shortened MOLLI (ShMOLLI) prototype 780C (CoV 0.69%). After adjusting for temperature and field strength, it was found that the T-1 mapping sequence and scanner software version (both P < 0.001 at 1.5 T and 3 T), and to a lesser extent the scanner model (P = 0.011, 1.5 T only), had the greatest influence on T-1 across multiple centers. Conclusion The T1MES CE/FDA approved phantom is a robust quality assurance device. In a multi-center setting, T-1 mapping had performance differences between field strengths, sequences, scanner software versions, and manufacturers. However, several specific combinations of field strength, sequence, and scanner are highly repeatable, and thus, have potential to provide standardized assessment of T-1 times for clinical use, although temperature correction is required for native T-1 tubes at least.