Comparison of quantitative regional perfusion-weighted phase resolved functional lung (PREFUL) MRI with dynamic gadolinium-enhanced regional pulmonary perfusion MRI in COPD patients.

Background: Perfusion-weighted noncontrast-enhanced proton lung MRI during free breathing is maturing as a novel technique for assessment of regional lung perfusion, but has not yet been validated in chronic obstructive pulmonary disease (COPD) patients.

Purpose: To compare pulmonary parenchymal perfusion assessed by noncontrast-enhanced perfusion-weighted phase-resolved functional lung (PREFUL)-MRI with lung perfusion determined with dynamic gadolinium-enhanced (DCE)-MRI and with lung function test parameters.

Study Type: Prospective.

Population: A single-center subset of the COPD cohort "COPD and SYstemic consequenzes-COmorbidities NETwork" (COSYCONET). Forty-seven patients with COPD (median age 66 [57-70] years) were studied.

Field Strength/sequence: For PREFUL-MRI a spoiled gradient echo sequence and for DCE-MRI, a 3D time-resolved spoiled gradient echo sequence was used at 1.5T.

Assessment: PREFUL-MRI coronal slices were acquired in free breathing. DCE-MRI was performed in breath-hold with administration of 0.025 mmol/kg bodyweight of gadobutrol i.v. at a rate of 4 ml/s and pulmonary blood flow (PBF) maps were calculated. Slices of PREFUL and DCE-MRI were matched by their ventrodorsal position and corresponding slices were coregistered for evaluation. Perfusion defect percentages (QDP) were calculated for both methods.

Statistical Tests: The obtained parameters were correlated using Spearman's correlation coefficient (r) and Bland-Altman plot analysis.

Results: PREFUL-QDP showed an absolute and spatial agreement with PBF-QDP on a global (39.3 (31.8-45.5)% vs. 44.7 (35.4-50.0)% with a spatial overlap of 62.2 (57.2-67.2)%)) as well as on a lobar level and correlated with lung function test parameters (PREFUL-QDP vs. FEV , r = -0.75, P < 0.0001). There was a systematic overestimation of PREFUL-QDP compared with PBF-QDP, mainly in the lower lobes, resulting in an overall overestimation for the whole lung with a mean difference of 5% (95% confidence interval [CI]: 3.0%; 7.0%; STD 6.8%).

Data Conclusion: PREFUL-MRI is a promising noninvasive, radiation-free tool for quantification of regional perfusion in COPD patients.

Level Of Evidence: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:1122-1132.