BACKGROUND: * of pulmonary tissues, improving image quality. Abnormally low UTE signal intensities are associated with hallmarks of cystic fibrosis (CF), including gas trapping and lung hyperexpansion. PURPOSE: To explore short-term repeatability and sensitivity to treatment of low signal volume (LSV) from UTE MRI in pediatric CF. STUDY-TYPE: Single-site, retrospective, longitudinal. SUBJECTS: Thirteen participants with stable CF (6M/7F, median age = 15 years old) were scanned at baseline and 1-month to evaluate short-term repeatability. Subsequently, 14 CF participants (7M/7F median age = 16 years old) were scanned pre- and 1-month post-initiation of elexacaftor/tezacaftor/ivacaftor (ETI). FIELD STRENGTH/SEQUENCE: Three-dimensional stack-of-spirals for UTE, 2-dimensional gradient-echo for hyperpolarized xenon (Xe-MRI), 3-dimensional gradient-echo for thoracic cavity estimation at 3 T. ASSESSMENT: LSV was analyzed from UTE MRI. Same-day spirometry, multiple-breath washout, and Xe-MRI were also performed to compare to LSV. STATISTICAL TESTS: Differences were assessed with the Wilcoxon matched-pairs signed-rank test. Bland-Altman analysis and the Intraclass Correlation Coefficient (ICC) were used to assess 1-month repeatability in stable CF. Relationships between measures were assessed with Spearman correlation. p < 0.05 was considered significant. RESULTS: /FVC, LCI, and VDP (all |ρ| ≥ 0.59). DATA CONCLUSION: LSV analysis was feasible and repeatable in pediatric CF over a 1-month period. LSV was significantly reduced 1-month after ETI treatment, indicating sensitivity to reduced gas trapping, hyperexpansion, and obstruction. EVIDENCE LEVEL: 4. TECHNICAL EFFICACY: 1.
Zanette et al. (Mon,) studied this question.