Estimation of pulmonary vascular resistance in patients with pulmonary fibrosis by phase-contrast magnetic resonance imaging

Purpose. The aim of this study was to assess pulmonary vascular resistance (PVR) in patients with pulmonary fibrosis (PF) by phase-contrast magnetic resonance imaging (MRI). Materials and methods. Subjects were 11 healthy volunteers and 11 patients with PF. Using phase-contrast MRI, we measured pulmonary arterial blood flow and calculated the parameters of PVR. Parameters were compared between volunteers and patients using unpaired t-tests. The diagnostic capability of the parameters was evaluated by receiver operating characteristic (ROC) curve analysis. Patients underwent respiratory function tests (RFTs) and chest computed tomography (CT), and they were correlated with MRI parameters. Results. Most MRI parameters were significantly different between volunteers and patients (t-test P values were <0.05 in 9 of 10 parameters). Regarding the RFT and CT visual score, only the %DLco/VA and acceleration time and the CT visual score and average flow volume had signifi cant correlation [r = -0.667 (P = 0.024) and r = -0.6 (P = 0.031)], respectively. Conclusion. Our findings suggest that PVR derived from phase-contrast MRI is significantly higher in patients with PF than in volunteers. However, all but two of these parameters may not correlate with the severity of PF.