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 ( 19 F‐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 19 F‐MRI a spoiled gradient echo sequence was used at 1.5T. Assessment FD‐MRI coronal slices were acquired in free breathing. Dynamic 19 F‐MRI was performed after inhalation of 25–30 L of a mixture of 79% fluorinated gas (C 3 F 8 ) and 21% oxygen via a closed face mask tubing using a dedicated coil tuned to 59.9 MHz. 19 F washout times in numbers of breaths ( 19 F‐n breaths ) as well as fractional ventilation maps for both methods (FD‐FV, 19 F‐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 19 F‐n breaths 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 19 F‐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.