Fully quantitative pulmonary perfusion metrics for the evaluation of lung disease can be difficult and time consuming to compute. We compare fully quantitative pulmonary blood flow (PBF) and mean transit time (MTT) to simpler semi-quantitative metrics slope and first moment transit time (FMTT) in idiopathic pulmonary fibrosis (IPF). We found strong correlations between the slope and PBF, as well as MTT and FMTT. A decrease in slope values was found in subjects with IPF when compared to healthy subjects. Slope could potentially be used as a surrogate for PBF to evaluate IPF.