Center for Pulmonary Imaging Research, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Pediatrics, University of Cincinnati Medical Center, Cincinnati, Ohio, USA.
J Magn Reson Imaging. 2022 Oct;56(4):1207-1219. doi: 10.1002/jmri.28136. Epub 2022 Mar 4.
Xe gas-transfer MRI provides regional measures of pulmonary gas exchange in adults and separates xenon in interstitial lung tissue/plasma (barrier) from xenon in red blood cells (RBCs). The technique has yet to be demonstrated in pediatric populations or conditions.
PURPOSE/HYPOTHESIS: To perform an exploratory analysis of Xe gas-transfer MRI in children.
Prospective.
Seventy-seven human volunteers (38 males, age = 17.7 ± 15.1 years, range 5-68 years, 16 healthy). Four pediatric disease cohorts.
FIELD STRENGTH/SEQUENCE: 3-T, three-dimensional-radial one-point Dixon Fast Field Echo (FFE) Ultrashort Echo Time (UTE).
Breath hold compliance was assessed by quantitative signal-to-noise and dynamic metrics. Whole-lung means and standard deviations were extracted from gas-transfer maps. Gas-transfer metrics were investigated with respect to age and lung disease. Clinical pulmonary function tests were retrospectively acquired for reference lung disease severity.
Wilcoxon rank-sum tests to compare age and disease cohorts, Wilcoxon signed-rank tests to compare pre- and post-breath hold vitals, Pearson correlations between age and gas-transfer metrics, and limits of normal with a binomial exact test to compare fraction of subjects with abnormal gas-transfer. P ≤ 0.05 was considered significant.
Eighty percentage of pediatric subjects successfully completed Xe gas-transfer MRI. Gas-transfer parameters differed between healthy children and adults, including ventilation (0.75 and 0.67) and RBC:barrier ratio (0.31 and 0.46) which also correlated with age (ρ = -0.76, 0.57, respectively). Bone marrow transplant subjects had impaired ventilation (90% of reference) and increased dissolved Xe standard deviation (242%). Bronchopulmonary dysplasia subjects had decreased barrier-uptake (69%). Cystic fibrosis subjects had impaired ventilation (91%) and increased RBC-transfer (146%). Lastly, childhood interstitial lung disease subjects had increased ventilation heterogeneity (113%). Limits of normal provided detection of abnormalities in additional gas-transfer parameters.
Pediatric Xe gas-transfer MRI was adequately successful and gas-transfer metrics correlated with age. Exploratory analysis revealed abnormalities in a variety of pediatric obstructive and restrictive lung diseases.
2 TECHNICAL EFFICACY STAGE: 2.
氙气转移 MRI 可提供成人肺部气体交换的区域性测量值，并将间质肺组织/血浆中的氙气（屏障）与红细胞中的氙气（RBC）分离。该技术尚未在儿科人群或疾病中得到证实。
目的/假设：对儿童进行氙气转移 MRI 进行探索性分析。
前瞻性。
77 名人类志愿者（38 名男性，年龄=17.7±15.1 岁，年龄 5-68 岁，16 名健康志愿者）。四个儿科疾病队列。
磁场强度/序列：3T，三维径向单点 Dixon 快速场回波（FFE）超短回波时间（UTE）。
通过定量信噪比和动态指标评估屏气顺应性。从气体转移图中提取全肺平均值和标准偏差。根据年龄和肺部疾病研究气体转移指标。回顾性获取临床肺功能测试作为参考肺部疾病严重程度。
Wilcoxon 秩和检验比较年龄和疾病队列，Wilcoxon 符号秩检验比较屏气前后生命体征，年龄与气体转移指标之间的 Pearson 相关，二项式精确检验正常范围与异常气体转移的受试者比例。P≤0.05 被认为具有统计学意义。
80%的儿科患者成功完成了氙气转移 MRI。健康儿童和成人之间的气体转移参数不同，包括通气（0.75 和 0.67）和 RBC：屏障比（0.31 和 0.46），这也与年龄相关（ρ=-0.76，0.57）。骨髓移植患者的通气受损（参考值的 90%），溶解氙标准偏差增加（242%）。支气管肺发育不良患者的屏障摄取减少（69%）。囊性纤维化患者的通气受损（91%）和 RBC 转移增加（146%）。最后，儿童间质性肺病患者的通气异质性增加（113%）。正常范围提供了对其他气体转移参数异常的检测。
儿科氙气转移 MRI 取得了足够的成功，气体转移指标与年龄相关。探索性分析显示各种儿科阻塞性和限制性肺部疾病存在异常。
2 技术功效阶段：2。
