To develop a free-breathing whole-heart isotropic-resolution 3D late gadolinium enhancement (LGE) sequence with Dixon-encoding, which provides co-registered 3D grey-blood phase-sensitive inversion-recovery (PSIR) and complementary 3D fat volumes in a single scan of < 7 min. A free-breathing 3D PSIR LGE sequence with dual-echo Dixon readout with a variable density Cartesian trajectory with acceleration factor of 3 is proposed. Image navigators are acquired to correct both inversion recovery (IR)-prepared and reference volumes for 2D translational respiratory motion, enabling motion compensated PSIR reconstruction with 100% respiratory scan efficiency. An intermediate PSIR reconstruction is performed between the in-phase echoes to estimate the signal polarity which is subsequently applied to the IR-prepared water volume to generate a water grey-blood PSIR image. The IR-prepared water volume is obtained using a water/fat separation algorithm from the corresponding dual-echo readout. The complementary fat-volume is obtained after water/fat separation of the reference volume. Ten patients (6 with myocardial scar) were scanned with the proposed water/fat grey-blood 3D PSIR LGE sequence at 1.5 T and compared to breath-held grey-blood 2D LGE sequence in terms of contrast ratio (CR), contrast-to-noise ratio (CNR), scar depiction, scar transmurality, scar mass and image quality. Comparable CRs (p = 0.98, 0.40 and 0.83) and CNRs (p = 0.29, 0.40 and 0.26) for blood-myocardium, scar-myocardium and scar-blood respectively were obtained with the proposed free-breathing 3D water/fat LGE and 2D clinical LGE scan. Excellent agreement for scar detection, scar transmurality, scar mass (bias = 0.29%) and image quality scores (from 1: non-diagnostic to 4: excellent) of 3.8 ± 0.42 and 3.6 ± 0.69 (p > 0.99) were obtained with the 2D and 3D PSIR LGE approaches with comparable total acquisition time (p = 0.29). Similar agreement in intra and inter-observer variability were obtained for the 2D and 3D acquisition respectively. The proposed approach enabled the acquisition of free-breathing motion-compensated isotropic-resolution 3D grey-blood PSIR LGE and fat volumes. The proposed approach showed good agreement with conventional 2D LGE in terms of CR, scar depiction and scan time, while enabling free-breathing acquisition, whole-heart coverage, reformatting in arbitrary views and visualization of both water and fat information.

中文翻译：

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3D全心灰血晚期钆增强心血管磁共振成像


开发具有 Dixon 编码的自由呼吸全心各向同性分辨率 3D 晚期钆增强 (LGE) 序列，该序列提供共同配准的 3D 灰血相敏反转恢复 (PSIR) 和互补的 3D 脂肪体积单次扫描 < 7 分钟提出了一种具有双回波 Dixon 读数的自由呼吸 3D PSIR LGE 序列，其具有加速因子为 3 的可变密度笛卡尔轨迹。采集图像导航器来校正 2D 平移呼吸运动的反转恢复 (IR) 准备体积和参考体积，从而实现运动补偿 PSIR 重建，呼吸扫描效率为 100%。在同相回波之间执行中间 PSIR 重建，以估计信号极性，随后将其应用于红外准备的水体积以生成水灰血 PSIR 图像。使用水/脂肪分离算法从相应的双回波读数获得红外制备的水体积。参考体积的水/脂肪分离后获得补充脂肪体积。使用建议的水/脂肪灰血 3D PSIR LGE 序列在 1.5 T 下对 10 名患者（6 名患有心肌疤痕）进行扫描，并在对比度 (CR)、对比比方面与屏气灰血 2D LGE 序列进行比较。 -噪声比（CNR）、疤痕描绘、疤痕透壁性、疤痕质量和图像质量。使用所提出的自由呼吸 3D 水/脂肪 LGE 和 2D 分别获得了血液-心肌、疤痕-心肌和疤痕-血液的可比 CR（p = 0.98、0.40 和 0.83）和 CNR（p = 0.29、0.40 和 0.26）临床 LGE 扫描。疤痕检测、疤痕透壁性、疤痕质量（偏差 = 0.29%）和图像质量评分（从 1：无法诊断到 4：优秀）达到 3.8 ± 0.42 和 3.6 ± 0。69 (p > 0.99) 是通过 2D 和 3D PSIR LGE 方法获得的，总采集时间相当 (p = 0.29)。 2D 和 3D 采集的观察者内和观察者间变异性分别获得了类似的一致性。所提出的方法能够采集自由呼吸运动补偿各向同性分辨率 3D 灰血 PSIR LGE 和脂肪体积。所提出的方法在 CR、疤痕描绘和扫描时间方面与传统 2D LGE 表现出良好的一致性，同时能够实现自由呼吸采集、全心脏覆盖、任意视图中的重新格式化以及水和脂肪信息的可视化。