AIMS To investigate the use of respiratory motion compensation using image-based navigation (iNAV) with constant respiratory efficiency using single end-expiratory thresholding (CRUISE) for coronary magnetic resonance angiography (CMRA), and compare it to the conventional diaphragmatic navigator (dNAV) in paediatric patients with congenital or suspected heart disease. METHODS iNAV allowed direct tracking of the respiratory heart motion and was generated using balanced steady state free precession startup echoes. Respiratory gating was achieved using CRUISE with a fixed 50% efficiency. Whole-heart CMRA was acquired with 1.3 mm isotropic resolution. For comparison, CMRA with identical imaging parameters were acquired using dNAV. Scan time, visualization of coronary artery origins and mid-course, imaging quality and sharpness was compared between the two sequences. RESULTS Forty patients (13 females; median weight: 44 kg; median age: 12.6, range: 3 months-17 years) were enrolled. 25 scans were performed in awake patients. A contrast agent was used in 22 patients. The scan time was significantly reduced using iNAV for awake patients (iNAV 7:48 ± 1:26 vs dNAV 9:48 ± 3:11, P = 0.01) but not for patients under general anaesthesia (iNAV = 6:55 ± 1:50 versus dNAV = 6:32 ± 2:16; P = 0.32). In 98% of the cases, iNAV image quality had an equal or higher score than dNAV. The visual score analysis showed a clear difference, favouring iNAV (P = 0.002). The right coronary artery and the left anterior descending vessel sharpness was significantly improved (iNAV: 56.8% ± 10.1% vs dNAV: 53.7% ± 9.9%, P < 0.002 and iNAV: 55.8% ± 8.6% vs dNAV: 53% ± 9.2%, P = 0.001, respectively). CONCLUSION iNAV allows for a higher success-rate and clearer depiction of the mid-course of coronary arteries in paediatric patients. Its acquisition time is shorter in awake patients and image quality score is equal or superior to the conventional method in most cases.

中文翻译：

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使用全心冠状动脉磁共振血管造影对儿科患者的冠状动脉进行可视化：图像导航与呼吸运动补偿标准方法的比较。


目的 研究使用基于图像的导航 (iNAV) 的呼吸运动补偿在冠状动脉磁共振血管造影 (CMRA) 中的使用以及使用单呼气末阈值 (CRUISE) 的恒定呼吸效率，并将其与传统膈肌导航器 (dNAV) 进行比较患有先天性或疑似心脏病的儿科患者。方法 iNAV 允许直接跟踪呼吸心脏运动，并使用平衡稳态自由进动启动回波生成。使用 CRUISE 实现呼吸门控，效率固定为 50%。以 1.3 mm 各向同性分辨率采集全心 CMRA。为了进行比较，使用 dNAV 获取具有相同成像参数的 CMRA。比较两个序列之间的扫描时间、冠状动脉起源和中段的可视化、成像质量和清晰度。结果 纳入 40 名患者（13 名女性；中位体重：44 kg；中位年龄：12.6 岁，范围：3 个月至 17 岁）。对清醒的患者进行了 25 次扫描。 22 名患者使用了造影剂。对于清醒患者，使用 iNAV 的扫描时间显着缩短（iNAV 7:48 ± 1:26 与 dNAV 9:48 ± 3:11，P = 0.01），但对于全身麻醉的患者则不然（iNAV = 6:55 ± 1： 50 与 dNAV = 6:32 ± 2:16；P = 0.32）。在 98% 的情况下，iNAV 图像质量得分与 dNAV 相同或更高。视觉评分分析显示出明显的差异，有利于 iNAV（P = 0.002）。右冠状动脉和左前降支血管清晰度显着改善（iNAV：56.8％±10.1％ vs dNAV：53.7％±9.9％，P <0.002和iNAV：55.8％±8.6％ vs dNAV：53％±9.2％ ，P = 0.001，分别）。 结论 iNAV 可以实现儿科患者冠状动脉中段的更高成功率和更清晰的描述。它在清醒患者中的采集时间较短，并且在大多数情况下图像质量评分等于或优于传统方法。