Wiesmueller Marco, Wuest Wolfgang, Heiss Rafael, Treutlein Christoph, Uder Michael, May Matthias Stefan
Department of Radiology, University Hospital Erlangen, Maximiliansplatz 3, 91054, Erlangen, Germany.
J Cardiovasc Magn Reson. 2020 May 28;22(1):39. doi: 10.1186/s12968-020-00619-x.
Interpretation of T2 values remains difficult due to limited comparability across hardware and software systems and the lack of validated measurement recommendations for the number and orientation of mandatory slices. Our aims were to provide a standardized comparison of intra- and inter-individual T2 values in the short and long axes and to investigate inter-scanner reproducibility.
Ninety cardiovascular magnetic resonance (CMR) studies in 30 healthy subjects were performed with three identical 1.5 T CMR scanners (same hardware and software) using a balanced steady-state free precession (bSSFP) gradient echo sequence in three short axis (SAx) and three long axis (LAx) views. A commercially available T2 mapping software package of the latest generation with automatic in-line motion correction was used for acquisition. Regions of interest were manually drawn in each of the 16 myocardial segments according to the American Heart Association (AHA) model in three SAx and three LAx acquisitions. Analysis of inter-scanner, inter-segmental, intra-segmental, inter-regional and inter-level differences was performed.
Inter-scanner reproducibility was high and the mean myocardial T2 value for all evaluated segments was 45.7 ± 3.4 ms. Significant inter-segmental variations of mean T2 values were found. Mean intra-segmental T2 values were comparable between LAx and SAx acquisitions in 72%. Significantly higher T2 values were found in apical segments and a significant disparity among different regions was found for SAx and LAx orientations.
Standardized cardiac T2 mapping is highly reproducible on identical CMR systems. T2 values vary significantly between single heart segments, regions, levels, and axes in young, healthy subjects.
由于硬件和软件系统之间的可比性有限，以及缺乏针对必需切片数量和方向的经过验证的测量建议，T2值的解读仍然困难。我们的目的是对短轴和长轴上个体内和个体间的T2值进行标准化比较，并研究不同扫描仪之间的可重复性。
使用三个相同的1.5T心脏磁共振成像（CMR）扫描仪（相同的硬件和软件），对30名健康受试者进行了90次CMR研究，采用平衡稳态自由进动（bSSFP）梯度回波序列，采集三个短轴（SAx）和三个长轴（LAx）视图。使用具有自动在线运动校正功能的最新一代商用T2映射软件包进行采集。根据美国心脏协会（AHA）模型，在三个SAx和三个LAx采集中，在16个心肌节段的每一个中手动绘制感兴趣区域。进行了不同扫描仪、节段间、节段内、区域间和层面间差异的分析。
不同扫描仪之间的可重复性很高，所有评估节段的平均心肌T2值为45.7±3.4毫秒。发现平均T2值存在显著的节段间差异。72%的节段内平均T2值在LAx和SAx采集中具有可比性。在心尖节段发现显著更高的T2值，并且在SAx和LAx方向上不同区域之间存在显著差异。
在相同的CMR系统上，标准化心脏T2映射具有高度可重复性。在年轻健康受试者中，T2值在单个心脏节段、区域、层面和轴之间存在显著差异。
