Ventilation defect percentage from PREFUL MRI in pediatric primary ciliary dyskinesia

<bold>Background:</bold> Primary ciliary dyskinesia (PCD) is a genetic disease with significant lung morbidity. We previously showed that ventilation defect percentage (VDP; the ratio of non-ventilating lung to thoracic volume) from hyperpolarized 129-Xe MRI (Xe-MRI) is a sensitive and repeatable lung function measure in PCD. Contrast-free, free-breathing imaging techniques like phase resolved functional lung MRI (PREFUL) have not been investigated in PCD, and offer the advantage of increased clinical translatability, especially in pediatrics. <bold>Objective:</bold> Determine the feasibility, validity, and repeatability of PREFUL VDP in pediatric PCD. <bold>Methods:</bold> Participants were recruited from SickKids, if they had a confirmed PCD diagnosis, >6 years, could breath-hold for 10 seconds, medically stable and not needing supplemental oxygen. Participants underwent same day repeat Xe-MRI and PREFUL scans. <bold>Results:</bold> 8 participants completed the study. The VDP from PREFUL had a significant and good agreement with Xe-MRI (R2=0.82, p<0.001). PREFUL had excellent repeatability based on the intraclass correlation of 0.94 and the Bland and Altman plot. Same day repeat scans show the ventilation defects, and corresponding VDP, from Xe-MRI and PREFUL (Figure). <bold>Conclusions:</bold> In PCD, PREFUL VDP demonstrated feasibility, validity, and repeatability. This suggests that PREFUL may be an alternative technique to Xe-MRI, the latter of which is not widely available. <fig><object-id>erj;64/suppl_68/PA3944/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>