Comparison of dissolved xenon imaging methods: 2D CSI vs 4-echo flyback radial spectroscopic imaging.

Motivation: Several dissolved xenon imaging methods have been proposed to detect impaired gas transfer in the lung. However, none have been validated against a gold standard CSI sequence. Goal(s): To validate quantitative xenon gas exchange metrics from a 4-echo radial EPSI implementation against those from CSI. Approach: 4-echo radial EPSI results were compared to CSI in 2 healthy volunteers. Results: We found good correlations between xenon gas exchange metrics from CSI and radial EPSI and minimal biases (0.4 to 5.8%) between the two methods for the main outcome parameter RBC:M, the ratio of dissolved xenon signals from the blood and in the membrane. Impact: Our implementation of dissolved xenon imaging using a 4-echo radial EPSI is validated against the reference standard CSI sequence, providing confidence in the quantitative nature of the xenon gas exchange metrics from this method to assess lung diseases.