Multiparametric oxygen-enhanced functional lung imaging in 3D.

ABSTRACT

OBJECTIVE: To develop a self-gated free-breathing 3D sequence allowing for simultaneous T1-weighted imaging and quantitative T2* mapping in different breathing phases in order to assess the feasibility of oxygen-enhanced 3D functional lung imaging. MATERIALS AND METHODS: A 3D sequence with ultrashort echo times and interleaved double readouts was implemented for oxygen-enhanced lung imaging at 1.5 T. Six healthy volunteers were examined while breathing room air as well as 100 % oxygen. Images from expiratory and inspiratory breathing phases were reconstructed and compared for the two breathing gases. RESULTS: The average T2* value measured for room air was 2.10 ms, with a 95 % confidence interval (CI) of 1.95-2.25 ms, and the average for pure oxygen was 1.89 ms, with a 95 % CI of 1.76-2.01 ms, resulting in a difference of 10.1 % (95 % CI 8.9-11.3 %). An 11.2 % increase in signal intensity (95 % CI 10.4-12.1 %) in the T 1-weighted images was detected when subjects were breathing pure oxygen compared to room air. Furthermore, a significant change in signal intensity (26.5 %, 95 % CI 18.8-34.3 %) from expiration to inspiration was observed. CONCLUSIONS: This study demonstrated the feasibility of simultaneous T2* mapping and T1-weighted 3D imaging of the lung. This method has the potential to provide information about ventilation, oxygen transfer, and lung expansion within one experiment. Future studies are needed to investigate the clinical applicability and diagnostic value of this approach in various pulmonary diseases.