Comparison of phase-resolved functional lung (PREFUL) MRI and CT parametric response mapping (PRM) in COSYCONET COPD
摘要
To compare regional ventilation assessed by non-contrast enhanced ventilation-weighted phase-resolved functional lung (PREFUL) MRI with parametric response mapping (PRM) and with pulmonary function test (PFT) parameters in patients with chronic obstructive pulmonary disease (COPD).
Materials and methodsThis study was a retrospective analysis of a single-center subset of the prospective COPD cohort COSYCONET. PREFUL MRI coronal sections were obtained during free breathing at 1.5 T using a spoiled gradient echo sequence. PRM was derived from paired low-dose inspiratory and expiratory CT scans. Matched coronal slices of PREFUL and PRM were co-registered. PREFUL ventilation defect percentage (PREFUL-VDP), as well as functional small airway disease (PRMfSAD), emphysema (PRMemph), and their combined metric (PRMfSAD+emph), were calculated.
Global comparisons employed Spearman’s correlation coefficient (r) and Wilcoxon signed-rank tests. Spatial agreement was assessed using spatial overlap and the Dice coefficient.
ResultsFifty-one patients (median age 65 [58–70]) were included in this study. PREFUL-VDP strongly correlated with combined PRMfSAD+emph (r = 0.86. p < 0.001) and with PFT parameters (PREFUL-VDP vs FEV1, r = −0.75, p < 0.001). Correlations between PREFUL-VDP with PRMfSAD and PRMemph separately were weaker (r = 0.57 and r = 0.82, p < 0.001 for both). In concordance, the highest spatial congruence was observed between PREFUL-VDP and PRMfSAD+emph (spatial overlap: 0.60 [0.55–0.66], Dice coefficient for defects: 0.53 [0.28–0.62]), indicating that PREFUL-VDP does not distinguish between small airway disease and emphysema.
ConclusionPREFUL-VDP correlates most strongly with the PRM measurement of emphysema and functional small airways disease combined and is a promising noninvasive, radiation-free tool for quantifying regional ventilation in COPD.
Key Points