Department of Pediatrics, Children's Medical Center Dallas, 1935 Medical District Dr, Dallas, TX, 75235, USA.
Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA.
Pediatr Radiol. 2024 Nov;54(12):2060-2067. doi: 10.1007/s00247-024-06061-w. Epub 2024 Oct 9.
Lymphatic imaging is becoming increasingly important in the management of patients with congenital heart disease. However, the influence of the intravenous contrast agent ferumoxytol on lymphatic imaging is not well understood.
To evaluate the impact of intravenous ferumoxytol on T1-weighted and T2-weighted lymphatic imaging in patients with congenital heart disease.
We included consecutive patients receiving ferumoxytol-enhanced 3D angiography for congenital heart disease evaluation. The visibility of the thoracic duct was reviewed on the T1-weighted 3D inversion recovery balanced-steady-state free precession (SSFP) with respiratory navigator gating sequence which is routinely used for angiography and the heavily T2-weighted turbo spin echo sequence which is employed for lymphatic imaging. Data on demographics and time interval between contrast administration and imaging were collected. Statistical analyses were performed using t-tests for continuous variables and chi-squared tests for categorical variables.
One hundred nineteen consecutive patients with a mean age of 12.46 years±7.7 years were included. Of these, 45 cases underwent both T1-weighted and T2-weighted imaging; the other 74 underwent only T1-weighted imaging. Of the 45 patients, 20 had thoracic duct enhancement on T1-weighted imaging; among the 26 sedated, only 2 showed enhancement, while 18 of 19 non-sedated patients showed enhancement (P<0.001), indicating a strong association between sedation and reduced thoracic duct visibility. If T2-weighted imaging was performed after contrast administration, the thoracic duct was not visible on those images. For all 45 cases of visible thoracic duct in the entire cohort, the time from contrast administration to imaging ranged from 8 min up to 75 min.
The enhancement of the thoracic lymphatic duct on T1-weighted imaging, coupled with degradation observed on T2-weighted imaging, suggests that intravenously administered ferumoxytol rapidly enters the lymphatic fluid. To prevent T2 shortening from degrading the imaging results, T2-weighted imaging for lymphatic evaluation should be performed prior to the administration of ferumoxytol. Sedation and, by inference, fasting may influence this property and warrant further investigation in future studies.
淋巴成像在先天性心脏病患者的治疗中变得越来越重要。然而，静脉注射用铁氧体对淋巴成像的影响尚不清楚。
评估静脉注射用铁氧体对先天性心脏病患者 T1 加权和 T2 加权淋巴成像的影响。
我们纳入了连续接受静脉注射用铁氧体增强 3D 血管造影以评估先天性心脏病的患者。在常规用于血管造影的 T1 加权 3D 反转恢复平衡稳态自由进动（SSFP）呼吸导航门控序列和用于淋巴成像的重 T2 加权涡轮自旋回波序列上，对胸导管的可视性进行了评估。收集人口统计学数据和造影剂给药与成像之间的时间间隔数据。使用 t 检验进行连续变量分析，使用卡方检验进行分类变量分析。
共纳入 119 例平均年龄为 12.46 岁±7.7 岁的连续患者。其中 45 例行 T1 加权和 T2 加权成像；其余 74 例行 T1 加权成像。在 45 例患者中，20 例 T1 加权成像显示胸导管增强；在 26 例镇静患者中，仅 2 例显示增强，而在 19 例非镇静患者中，18 例显示增强（P<0.001），表明镇静与胸导管可视性降低之间存在很强的关联。如果在造影剂给药后进行 T2 加权成像，则在这些图像上无法显示胸导管。对于整个队列中所有 45 例可见胸导管的患者，造影剂给药与成像之间的时间从 8 分钟到 75 分钟不等。
T1 加权成像上胸淋巴导管的增强，加上 T2 加权成像上观察到的退化，表明静脉内给予的铁氧体迅速进入淋巴液。为防止 T2 缩短导致成像结果恶化，应在给予铁氧体之前进行 T2 加权成像以评估淋巴。镇静（以及推断的禁食）可能会影响这种特性，需要在未来的研究中进一步探讨。
