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-n_breaths) 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-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 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 2017.

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