Non-contrast quantitative pulmonary perfusion using flow alternating inversion recovery at 3 T: A preliminary study

Purpose To demonstrate the initial feasibility of non-contrast quantitative pulmonary perfusion imaging at 3 T using flow alternating inversion recovery (FAIR), and to evaluate the intra-session and inter-session reliability of FAIR measurements at 3 T. Materials and methods Nine healthy volunteers were imaged using our own implementation of FAIR pulse sequence at 3 T. Quantitative FAIR perfusion, both with and without larger pulmonary vessels, was correlated with global phase contrast (PC) measured blood flow in the right pulmonary artery (RPA). The same volunteers were also imaged with SPECT perfusion using technetium-99 m-macroaggregated albumin and relative dispersion (RD) was assessed between FAIR and SPECT perfusion. Four additional healthy volunteers were evaluated for FAIR repeatability, using intra-class correlation coefficient (ICC) and Bland-Altman analysis. p < 0.05 was considered statistically significant. Results FAIR perfusion across all subjects was 858 ± 605 mL/100 g/min (with vessels) and 629 ± 294 mL/100 g/min (without vessels) and correlated significantly with the PC measured blood flow in the RPA (r = 0.62, p < 0.01 with vessels; r = 0.73, p < 0.001 without vessels). The median RD of FAIR perfusion across all subjects was 0.73 (with vessels) and 0.49 (without vessels), compared against 0.23 with SPECT perfusion. The intra/inter-session ICC of FAIR perfusion with vessels was 0.95/0.59 and improved to 0.96/0.72, when vessels were removed. Conclusions Non-contrast quantitative pulmonary perfusion imaging using FAIR is feasible at 3 T. This may serve as a reliable method to assess regional lung perfusion at 3 T to characterize and monitor treatment response in chronic lung disease without the concerns of repeated exposure to ionizing radiation or the accumulation of exogenous contrast agent.