Hyperpolarised xenon-129 MRI (129Xe-MRI) of lung in healthy adult volunteers

Introduction: 129Xe-MRI is a recently developed technology that enhances the applicability of MRI in lung imaging. Aim: We aimed to assess the feasibility and tolerability of 129Xe-MRI in healthy adult volunteers (HV). Method: This was a single centre observational study. HV were screened,and written consent obtained. After an initial test dose of non-polarised xenon, we proceeded to 129Xe-MRI. For each scan, HV inhaled 0.6-1.0L hyperpolarised 129Xe, and were observed for 30 minutes afterwards. Each visit comprised of a maximum of 4 scans. Results: 8 HV (male:female 7:1,aged 20-34) underwent 20 scan visits. 129Xe-MRI was well-tolerated, with no adverse events. No significant change in oxygen saturations (mean difference 30min post-scan (MD30PS) 0.10,standard deviation (SD) 1.27,confidence interval (CI) -0.22 to -0.43,p=0.48) or blood pressure (MD30PS 1.59,SD 7.50,CI -0.39 to 30.58,p=0.07) was seen. A statistically significant difference was seen in heart rate (MD30PS -3.69, SD 7.34,CI -5.56 to -1.82,p=0.00003), deemed clinically insignificant. We achieved good image quality. Spectroscopy distinguished lung tissue-dissolved Xe from blood-dissolved; dissolved phase imaging (DPI) was obtained.The technique was reproducible. Discussion: The data demonstrates satisfactory feasibility and tolerability of 129Xe-MRI. DPI can potentially image regional gas exchange. 129Xe-MRI may be used to develop biomarkers of disease progression and drug efficacy.