Comparison of quantitative regional ventilation‐weighted fourier decomposition MRI with dynamic fluorinated gas washout MRI and lung function testing in COPD patients

Background Ventilation‐weighted Fourier decomposition‐MRI (FD‐MRI) has matured as a reliable technique for quantitative measures of regional lung ventilation in recent years, but has yet not been validated in COPD patients. Purpose/Hypothesis To compare regional fractional lung ventilation obtained by ventilation‐weighted FD‐MRI with dynamic fluorinated gas washout MRI (19F‐MRI) and lung function test parameters. Study Type Prospective study. Population Twenty‐seven patients with chronic obstructive pulmonary disease (COPD, median age 61 [54–67] years) were included. Field Strength/Sequence For FD‐MRI and for 19F‐MRI a spoiled gradient echo sequence was used at 1.5T. Assessment FD‐MRI coronal slices were acquired in free breathing. Dynamic 19F‐MRI was performed after inhalation of 25–30 L of a mixture of 79% fluorinated gas (C3F8) and 21% oxygen via a closed face mask tubing using a dedicated coil tuned to 59.9 MHz. 19F washout times in numbers of breaths (19F‐nbreaths) as well as fractional ventilation maps for both methods (FD‐FV, 19F‐FV) were calculated. Slices were matched using a landmark driven algorithm, and only corresponding slices with an overlap of >90% were coregistered for evaluation. Statistical Tests The obtained parameters were correlated with each other using Spearman's correlation coefficient (r). Results FD‐FV strongly correlated with 19F‐nbreaths on a global (r = –0.72, P < 0.0001) as well as on a lobar level and with lung function test parameters (FD‐FV vs. FEV1, r = 0.76, P < 0.0001). There was a small systematic overestimation of FD‐FV compared to 19F‐FV (mean difference –0.03 (95% confidence interval [CI]: –0.097; –0.045). Data Conclusion Regional ventilation‐weighted Fourier decomposition‐MRI is a promising noninvasive, radiation‐free tool for quantification of regional ventilation in COPD patients. Level of Evidence: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1534–1541.