From the Departments of Diagnostic and Interventional Radiology (J.F.H., P.J.K., J.P.G., R.H., A.M.W., T.A.B., H.K.) and Pediatrics (H.H.), University Hospital Würzburg, Oberdürrbacher Strasse 6, 97080 Würzburg, Germany; Department of Pediatric Radiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany (C.M., S.V.); and Department of MR Application Predevelopment, Siemens Healthcare, Erlangen, Germany (T.B.).
Radiology. 2023 Jul;308(1):e230084. doi: 10.1148/radiol.230084.
Background The triple combination of the cystic fibrosis transmembrane regulator (CFTR) modulators elexacaftor, tezacaftor, and ivacaftor (hereafter, elexacaftor/tezacaftor/ivacaftor) has a positive effect on lung function in patients with cystic fibrosis (CF). Purpose To compare three-dimensional (3D) ultrashort echo time (UTE) MRI functional lung data to common functional lung parameters in assessing lung function in patients with CF undergoing elexacaftor/tezacaftor/ivacaftor therapy. Materials and Methods In this prospective feasibility study, 16 participants with CF consented to undergo pulmonary MRI with a breath-hold 3D UTE sequence at baseline (April 2018-June 2019) and follow-up (April-July 2021). Eight participants received elexacaftor/tezacaftor/ivacaftor after baseline, and eight participants with unchanged treatment served as the control group. Lung function was assessed with body plethysmography and lung clearance index (LCI). Image-based functional lung parameters, such as ventilation inhomogeneity and ventilation defect percentage (VDP), were calculated from signal intensity change between MRI scans at inspiration and expiration. Metrics at baseline and follow-up were compared within groups (permutation test), correlation was tested (Spearman rank correlation), and 95% CIs were calculated (bootstrapping technique). Results MRI ventilation inhomogeneity correlated with LCI at baseline ( = 0.92, < .001) and follow-up ( = 0.81, = .002). Mean MRI ventilation inhomogeneity (baseline, 0.74 ± 0.15 [SD]; follow-up, 0.64 ± 0.11; = .02) and mean VDP (baseline, 14.1% ± 7.4; follow-up, 8.5% ± 3.3; = .02) decreased from baseline to follow-up in the treatment group. Lung function was stable over time (mean LCI: 9.3 turnovers ± 4.1 at baseline vs 11.5 turnovers ± 7.4 at follow-up; = .34) in the control group. In all participants, correlation of forced expiratory volume in 1 second with MRI ventilation inhomogeneity was good at baseline ( = -0.61, = .01) but poor during follow-up ( = -0.06, = .82). Conclusion Noncontrast 3D UTE lung MRI functional parameters of ventilation inhomogeneity and VDP can be used to assess lung function over time in patients with CF and can add regional information to established global parameters, such as LCI. © RSNA, 2023 See also the editorial by Iwasawa in this issue.
背景 囊性纤维化跨膜转导调节因子（CFTR）调节剂依伐卡托、泰比卡托和艾氟卡托的三联组合（以下简称依伐卡托/泰比卡托/艾氟卡托）对囊性纤维化（CF）患者的肺功能有积极影响。目的 比较三维（3D）超短回波时间（UTE）MRI 功能肺数据与常见功能肺参数，以评估接受依伐卡托/泰比卡托/艾氟卡托治疗的 CF 患者的肺功能。材料与方法 本前瞻性可行性研究纳入 16 名 CF 患者，他们同意在基线（2018 年 4 月至 2019 年 6 月）和随访（2021 年 4 月至 7 月）时进行屏气 3D UTE 序列肺部 MRI。8 名患者在基线后接受依伐卡托/泰比卡托/艾氟卡托治疗，8 名治疗未改变的患者作为对照组。通过体描仪和肺清除指数（LCI）评估肺功能。从 MRI 扫描在吸气和呼气之间的信号强度变化中计算基于图像的功能肺参数，如通气不均匀性和通气缺陷百分比（VDP）。比较组内基线和随访时的指标（置换检验），测试相关性（Spearman 秩相关），并计算 95%CI（自举技术）。结果 MRI 通气不均匀性与基线时的 LCI 相关（ = 0.92， <.001）和随访时的 LCI 相关（ = 0.81， =.002）。治疗组基线时和随访时的平均 MRI 通气不均匀性（分别为 0.74 ± 0.15[SD]和 0.64 ± 0.11； =.02）和平均 VDP（分别为 14.1% ± 7.4%和 8.5% ± 3.3%； =.02）均从基线下降到随访。对照组肺功能随时间稳定（平均 LCI：基线时为 9.3 次换气±4.1，随访时为 11.5 次换气±7.4； =.34）。在所有参与者中，第 1 秒用力呼气量与 MRI 通气不均匀性的相关性在基线时良好（ = -0.61， =.01），但在随访时较差（ = -0.06， =.82）。结论 非对比 3D UTE 肺部 MRI 功能通气不均匀性和 VDP 等参数可用于评估 CF 患者随时间推移的肺功能，并可将区域信息添加到 LCI 等已建立的全局参数中。
