School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK.
MR Research Collaborations, Siemens Healthcare, Frimley, UK.
J Cardiovasc Magn Reson. 2020 Jul 20;22(1):53. doi: 10.1186/s12968-020-00649-5.
Conventional 2D inversion recovery (IR) and phase sensitive inversion recovery (PSIR) late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) have been widely incorporated into routine CMR for the assessment of myocardial viability. However, reliable suppression of fat signal, and increased isotropic spatial resolution and volumetric coverage within a clinically feasible scan time remain a challenge. In order to address these challenges, this work proposes a highly efficient respiratory motion-corrected 3D whole-heart water/fat LGE imaging framework.
An accelerated IR-prepared 3D dual-echo acquisition and motion-corrected reconstruction framework for whole-heart water/fat LGE imaging was developed. The acquisition sequence includes 2D image navigators (iNAV), which are used to track the respiratory motion of the heart and enable 100% scan efficiency. Non-rigid motion information estimated from the 2D iNAVs and from the data itself is integrated into a high-dimensional patch-based undersampled reconstruction technique (HD-PROST), to produce high-resolution water/fat 3D LGE images. A cohort of 20 patients with known or suspected cardiovascular disease was scanned with the proposed 3D water/fat LGE approach. 3D water LGE images were compared to conventional breath-held 2D LGE images (2-chamber, 4-chamber and stack of short-axis views) in terms of image quality (1: full diagnostic to 4: non-diagnostic) and presence of LGE findings.
Image quality was considered diagnostic in 18/20 datasets for both 2D and 3D LGE magnitude images, with comparable image quality scores (2D: 2.05 ± 0.72, 3D: 1.88 ± 0.90, p-value = 0.62) and overall agreement in LGE findings. Acquisition time for isotropic high-resolution (1.3mm) water/fat LGE images was 8.0 ± 1.4 min (3-fold acceleration, 60-88 slices covering the whole heart), while 2D LGE images were acquired in 5.6 ± 2.2 min (12-18 slices, including pauses between breath-holds) albeit with a lower spatial resolution (1.40-1.75 mm in-plane × 8 mm slice thickness).
A novel framework for motion-corrected whole-heart 3D water/fat LGE imaging has been introduced. The method was validated in patients with known or suspected cardiovascular disease, showing good agreement with conventional breath-held 2D LGE imaging, but offering higher spatial resolution, improved volumetric coverage and good image quality from a free-breathing acquisition with 100% scan efficiency and predictable scan time.
传统的二维反转恢复（IR）和相位敏感反转恢复（PSIR）晚期钆增强（LGE）心血管磁共振（CMR）已广泛纳入常规 CMR 用于评估心肌活力。然而，可靠地抑制脂肪信号，以及在临床可行的扫描时间内提高各向同性空间分辨率和容积覆盖范围仍然是一个挑战。为了解决这些挑战，本研究提出了一种高效的呼吸运动校正的 3D 全心水/脂 LGE 成像框架。
开发了一种用于全心水/脂 LGE 成像的加速 IR 准备的 3D 双回波采集和运动校正重建框架。采集序列包括 2D 图像导航仪（iNAV），用于跟踪心脏的呼吸运动，并实现 100%的扫描效率。从 2D iNAV 和数据本身估计的非刚性运动信息被整合到高维基于补丁的欠采样重建技术（HD-PROST）中，以产生高分辨率的水/脂 3D LGE 图像。一组 20 名已知或疑似心血管疾病的患者使用所提出的 3D 水/脂 LGE 方法进行了扫描。3D 水 LGE 图像在图像质量（1：完全诊断至 4：无法诊断）和 LGE 发现方面与传统的屏气 2D LGE 图像（2 腔、4 腔和短轴堆叠视图）进行了比较。
2D 和 3D LGE 幅度图像的 18/20 个数据集的图像质量被认为是诊断性的，具有可比的图像质量评分（2D：2.05±0.72，3D：1.88±0.90，p 值=0.62）和 LGE 发现的总体一致性。各向同性高分辨率（1.3mm）水/脂 LGE 图像的采集时间为 8.0±1.4 分钟（3 倍加速，60-88 个切片覆盖整个心脏），而 2D LGE 图像的采集时间为 5.6±2.2 分钟（12-18 个切片，包括屏气之间的暂停），尽管空间分辨率较低（1.40-1.75mm 面内×8mm 层厚）。
介绍了一种用于运动校正全心 3D 水/脂 LGE 成像的新框架。该方法在已知或疑似心血管疾病的患者中进行了验证，与传统的屏气 2D LGE 成像具有良好的一致性，但提供了更高的空间分辨率、改进的容积覆盖范围和良好的图像质量，同时具有 100%的扫描效率和可预测的扫描时间的自由呼吸采集。
