目的探讨自由呼吸胸部亮血四维(4D)动态MRI(dMRI)表征健康儿童和胸廓功能不全综合征(TIS)患者实质肺组织通气的特征。材料与方法收集2009年7月至2017年6月所有TIS患者的dMR图像。研究了标准化信号强度(sSI),首先使用肺通气体模建立可行性和敏感性,然后在40名健康儿童的回顾性研究中(16名男性,24名女性;平均年龄,9.6年±2.1[SD]),手术前后20例TIS患者(11例男性,九名女性;平均年龄,6.2年±4.2),和另外10名接受重复dMRI检查的健康儿童(7名男性,三名女性;平均年龄,9年±3.6)。对4DdMR图像中的单个肺进行了分割,并在呼气末(EE)评估每个肺的sSI,最终灵感(EI),术前,术后,与正常肺相比,在重复扫描中。结果通过sSI在体模中可检测到约6%的空气含量变化。体模内的sSI与空气占用率显着相关(皮尔逊相关系数=-0.96[P<.001])。对于健康的孩子,右肺sSI显著低于左肺sSI(EE:41±6vs47±6,EI:39±6vs43±7;P<.001),EI时肺sSI显著低于EE时(P<.001),EE时左肺sSI随年龄线性下降(r=-0.82)。患者手术后EE和EI的肺sSI降低(尽管没有统计学意义,术前sSI与术后sSI的P值,左肺和右肺分开,在0.13-0.51的范围内)。sSI在重复扫描之间在1.6%-4.7%内变化。结论这项研究证明了当空气占有率变化时,通过亮血dMRI检测体模中sSI变化的可行性。在患有TIS的儿科患者中,手术后观察到的平均肺sSI降低可能表明术后实质通气的改善。关键词:磁共振成像,胸部,肺,儿科,胸外科,肺实质通气,自由呼吸动态MRI,MRI强度标准化,本文提供了胸腔功能不全综合征的补充材料。©RSNA,2024.
Purpose To investigate free-breathing thoracic bright-blood four-dimensional (4D) dynamic MRI (dMRI) to characterize aeration of parenchymal lung tissue in healthy children and patients with thoracic insufficiency syndrome (TIS). Materials and Methods All dMR images in patients with TIS were collected from July 2009 to June 2017. Standardized signal intensity (sSI) was investigated, first using a lung aeration phantom to establish feasibility and sensitivity and then in a retrospective research study of 40 healthy children (16 male, 24 female; mean age, 9.6 years ± 2.1 [SD]), 20 patients with TIS before and after surgery (11 male, nine female; mean age, 6.2 years ± 4.2), and another 10 healthy children who underwent repeated dMRI examinations (seven male, three female; mean age, 9 years ± 3.6). Individual lungs in 4D dMR images were segmented, and sSI was assessed for each lung at end expiration (EE), at end inspiration (EI), preoperatively, postoperatively, in comparison to normal lungs, and in repeated scans. Results Air content changes of approximately 6% were detectable in phantoms via sSI. sSI within phantoms significantly correlated with air occupation (Pearson correlation coefficient = -0.96 [P < .001]). For healthy children, right lung sSI was significantly lower than that of left lung sSI (at EE: 41 ± 6 vs 47 ± 6 and at EI: 39 ± 6 vs 43 ± 7, respectively; P < .001), lung sSI at EI was significantly lower than that at EE (P < .001), and left lung sSI at EE linearly decreased with age (r = -0.82). Lung sSI at EE and EI decreased after surgery for patients (although not statistically significantly, with P values of sSI before surgery vs sSI after surgery, left and right lung separately, in the range of 0.13-0.51). sSI varied within 1.6%-4.7% between repeated scans. Conclusion This study demonstrates the feasibility of detecting change in sSI in phantoms via bright-blood dMRI when air occupancy changes. The observed reduction in average lung sSI after surgery in pediatric patients with TIS may indicate postoperative improvement in parenchymal aeration. Keywords: MR Imaging, Thorax, Lung, Pediatrics, Thoracic Surgery, Lung Parenchymal Aeration, Free-breathing Dynamic MRI, MRI Intensity Standardization, Thoracic Insufficiency Syndrome Supplemental material is available for this article. © RSNA, 2024.