Dynamic pulmonary perfusion imaging in patients with idiopathic pulmonary arterial hypertension

Abstract

Objective To investigate the value of dynamic PPI in patients with IPAH.Methods Twenty consecutive patients with IPAH underwent dynamic PPI and right ventricular catheterization.Ten healthy volunteers were also recruited in this study as control.Total lung ROI was drawn to calculate time-activity curves from dynamic PPI.Lung equilibrium time (LET),the duration from 99Tcm-MAA entering the lungs to equilibrium,was measured.Comparisons between two groups were carried out using t-test.Correlations between LET and hemodynamic parameters were determined by Pearson correlation analysis.Results LET was significantly prolonged in IPAH patients over the control group ( (33.9 ± 15.5) s vs ( 14.4 ± 3.7) s,t =5.340,P ＜0.001).Significant correlations were found between LET and mPAP(r =0.566,P ＜0.01) and between LET and total pulmonary resistance (TPR) measured by right heart catheterization (r =0.688,P ＜0.05).LET had a negative linear relationship with CI (r=-0.480,P ＜0.05).Conclusion Dynamic PPI is a practical and noninvasive method for evaluating the haemodynamic function of right heart in patients with IPAH. Key words: Hypertension, pulmonary; Radionuclide imaging; MAA