Repeatability of Standalone versus Image-Acquisition-Integrated 129Xe Spectroscopy

Motivation: 129Xe spectral parameters of lung airspaces, membrane tissues and red blood cells (RBC), provided by an MRS calibration scan, are important indicators of gas exchange function. Goal(s): Currently, such spectra are often acquired separately from gas exchange images, but it may be feasible to integrate 129Xe gas-exchange MRI and MRS into one scan, and test its repeatability. Approach: In this study, we assess the performance of image-acquisition-integrated spectra and compare them with a dedicated spectroscopicacquisition. Results: In subjects with a range of diseases, image-acquisition-integrated spectra were less repeatable than dedicated ones. However, increasing the number of averaged FIDS to 1second may yield equivalent performance. Impact: The repeatability of 129Xe spectroscopy integrated with imaging would be improved by collecting and averaging at least 1 second of data.