Quantification of Pulmonary Perfusion with Free-Breathing Dynamic Contrast-Enhanced MRI – A Pilot Study in Healthy Volunteers

Abstract

The assessment of pulmonary perfusion using dynamic contrast-enhanced (DCE) MRI is still limited in the clinical routine due to the necessity of breath holding. An acquisition technique for the quantitative assessment of pulmonary perfusion in free breathing was investigated in our study. 10 healthy male volunteers underwent pulmonary DCE-MRI on a 1.5 T scanner. Each volunteer was examined twice: (a) in breath-hold half expiration and (b) during shallow free breathing. The pulmonary parenchyma was segmented automatically. The pulmonary plasma flow (PPF) and pulmonary plasma volume (PPV) were determined pixel-wise using a one-compartment model. All examinations were of diagnostic image quality. The measured mean values of the PPV were significantly lower in the breath-hold technique than during free breathing ((10.2 ± 2.8) ml/100 ml vs. (12.7 ± 3.9) ml/100 ml); p < 0.05). A significant difference was also observed between both PPF measurements (mean PPF (206.2 ± 104.0) ml/100 ml/min in breath-hold technique vs. (240.6 ± 114.0) ml/100 ml/min during free breathing; p < 0.05). Free-breathing DCE-MRI appears to be suitable for the quantitative assessment of the pulmonary perfusion in healthy volunteers. The proposed segmentation and quantification approach does not suffer from the increased motion, as compared to the breath-holding measurement. The increased PPV and PPF during free breathing are in accordance with the results of previous studies concerning breathing influence on perfusion parameters. Overall, free-breathing DCE-MRI may be a promising technique for the assessment of pulmonary perfusion in various pathologies.