Assessment of pulmonary structure–function relationships in young children and adolescents with cystic fibrosis by multivolume proton‐MRI and CT

• Published in: Journal of magnetic resonance imaging Vol. 48; no. 2; pp. 531 - 542
• Main Authors: Pennati, Francesca, Roach, David J., Clancy, John P., Brody, Alan S., Fleck, Robert J., Aliverti, Andrea, Woods, Jason C.
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.08.2018
• Subjects: Abnormalities; Adolescent; Adolescents; Biomarkers; Bronchiectasis; Child; Child, Preschool; Children; Computed tomography; Correlation analysis; Cystic fibrosis; Cystic Fibrosis - diagnostic imaging; Dependence; Disease Progression; Feasibility studies; Female; Field strength; Functional Residual Capacity; Gravity; Heterogeneity; Humans; Image detection; Infant; lung; Lung - diagnostic imaging; Lung diseases; Magnetic Resonance Imaging; Male; Medical imaging; Morbidity; pediatrics; Population (statistical); Population studies; Protons; Regression analysis; Respiration; Respiratory Function Tests; Retrospective Studies; Statistical analysis; Statistical tests; Structure-function relationships; Teenagers; Thickening; Tomography, X-Ray Computed; Total Lung Capacity; Tracers; Variance analysis; Ventilation; Young Adult; lung; cystic fibrosis; pediatrics
• ISSN: 1053-1807; 1522-2586; 1522-2586
• DOI: 10.1002/jmri.25978

Background Lung disease is the most frequent cause of morbidity and mortality in patients with cystic fibrosis (CF), and there is a shortage of sensitive biomarkers able to regionally monitor disease progression and to assess early responses to therapy. Purpose To determine the feasibility of noncontrast‐enhanced multivolume MRI, which assesses intensity changes between expiratory and inspiratory breath‐hold images, to detect and quantify regional ventilation abnormalities in CF lung disease, with a focus on the structure–function relationship. Study Type Retrospective. Population Twenty‐nine subjects, including healthy young children (n = 9, 7–37 months), healthy adolescents (n = 4, 14–22 years), young children with CF lung disease (n = 10, 7–47 months), and adolescents with CF lung disease (n = 6, 8–18 years) were studied. Field Strength/Sequence 3D spoiled gradient‐recalled sequence at 1.5T. Assessment Subjects were scanned during breath‐hold at functional residual capacity (FRC) and total lung capacity (TLC) through noncontrast‐enhanced MRI and CT. Expiratory‐inspiratory differences in MR signal‐intensity (Δ1H‐MRI) and CT‐density (ΔHU) were computed to estimate regional ventilation. MR and CT images were also evaluated using a CF‐specific scoring system. Statistical Tests Quadratic regression, Spearman's correlation, one‐way analysis of variance (ANOVA). Results Δ1H‐MRI maps were sensitive to ventilation heterogeneity related to gravity dependence in healthy lung and to ventilation impairment in CF lung disease. A high correlation was found between MRI and CT ventilation maps (R2 = 0.79, P < 0.001). Globally, Δ1H‐MRI and ΔHU decrease with increasing morphological score (respectively, R2 = 0.56, P < 0.001 and R2 = 0.31, P < 0.001). Locally, Δ1H‐MRI was higher in healthy regions (median 15%) compared to regions with bronchiectasis, air trapping, consolidation, and to segments fed by airways with bronchial wall thickening (P < 0.001). Data Conclusion Multivolume noncontrast‐enhanced MRI, as a nonionizing imaging modality that can be used on nearly any MRI scanner without specialized equipment or gaseous tracers, may be particularly valuable in CF care, providing a new imaging biomarker to detect early alterations in regional lung structure–function. Level of Evidence: 3 Technical Efficacy: Stage 3 J. MAGN. RESON. IMAGING 2018;48:531–542.