Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany.
Charité Medical Faculty University Medicine, Berlin, Germany.
Magn Reson Med. 2020 Feb;83(2):438-451. doi: 10.1002/mrm.27935. Epub 2019 Aug 16.
To improve the efficiency of native and postcontrast high-resolution cardiac T mapping by utilizing cardiac motion correction.
Common cardiac T mapping techniques only acquire data in a small part of the cardiac cycle, leading to inefficient data sampling. Here, we present an approach in which 80% of each cardiac cycle is used for T mapping by integration of cardiac motion correction. Golden angle radial data was acquired continuously for 8 s with in-plane resolution of 1.3 × 1.3 mm . Cine images were reconstructed for nonrigid cardiac motion estimation. Images at different TIs were reconstructed from the same data, and motion correction was performed prior to T mapping. Native T mapping was evaluated in healthy subjects. Furthermore, the technique was applied for postcontrast T mapping in 5 patients with suspected fibrosis.
Cine images with high contrast were obtained, leading to robust cardiac motion estimation. Motion-corrected T maps showed myocardial T times similar to cardiac-triggered T maps obtained from the same data (1288 ± 49 ms and 1259 ± 55 ms, respectively) but with a 34% improved precision (spatial variation: 57.0 ± 12.5 ms and 94.8 ± 15.4 ms, respectively, P < 0.0001) due to the increased amount of data. In postcontrast T maps, focal fibrosis could be confirmed with late contrast-enhancement images.
The proposed approach provides high-resolution T maps within 8 s. Data acquisition efficiency for T mapping was improved by a factor of 5 by integration of cardiac motion correction, resulting in precise T maps.
通过利用心脏运动校正来提高原生和对比后高分辨率心脏 T 映射的效率。
常见的心脏 T 映射技术仅在心脏周期的一小部分获取数据，导致数据采样效率低下。在这里，我们提出了一种方法，通过整合心脏运动校正，将每个心脏周期的 80%用于 T 映射。使用黄金角度径向数据连续采集 8 秒，平面分辨率为 1.3×1.3mm。重建电影图像以进行非刚性心脏运动估计。从同一数据重建不同 TI 的图像，并在进行 T 映射之前进行运动校正。在健康受试者中评估原生 T 映射。此外，该技术还应用于 5 例疑似纤维化的患者的对比后 T 映射。
获得了对比度高的电影图像，从而实现了稳健的心脏运动估计。运动校正后的 T 图显示心肌 T 时间与从同一数据获得的心脏触发 T 图相似（分别为 1288±49ms 和 1259±55ms），但精度提高了 34%（空间变化：分别为 57.0±12.5ms 和 94.8±15.4ms，P<0.0001），因为数据量增加了。在对比后 T 图中，可以通过晚期对比增强图像确认局灶性纤维化。
该方法可在 8 秒内提供高分辨率 T 图。通过整合心脏运动校正，T 映射的数据采集效率提高了 5 倍，从而获得了精确的 T 图。
