Comparison of quantitative regional ventilation-weighted fourier decomposition MRI with dynamic fluorinated gas...

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.

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.

Prospective study.

Twenty-seven patients with chronic obstructive pulmonary disease (COPD, median age 61 [54-67] years) were included.

For FD-MRI and for ¹⁹ F-MRI a spoiled gradient echo sequence was used at 1.5T.

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 (C₃ F₈ ) 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.

The obtained parameters were correlated with each other using Spearman's correlation coefficient (r).

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).

Regional ventilation-weighted Fourier decomposition-MRI is a promising noninvasive, radiation-free tool for quantification of regional ventilation in COPD patients.

2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1534-1541.