BACKGROUND: Development of antiinflammatory drugs for lung diseases demands novel methods for noninvasive assessment of inflammatory processes in the lung. PURPOSE: To investigate the feasibility of hyperpolarized (129) Xe MRI, (1) H T1 time mapping, and dynamic contrast-enhanced (DCE) perfusion MRI for monitoring the response of human lungs to low-dose inhaled lipopolysaccharide (LPS) challenge compared to inflammatory cell counts from induced-sputum analysis. STUDY TYPE: Prospective feasibility study. POPULATION: Ten healthy volunteers underwent MRI before and 6 hours after inhaled LPS challenge with subsequent induced-sputum collection. FIELD STRENGTH/SEQUENCES: 1.5T/hyperpolarized (129) Xe MRI: Interleaved multiecho imaging of dissolved and gas phase, ventilation imaging, dissolved-phase spectroscopy, and chemical shift saturation recovery spectroscopy. (1) H MRI: Inversion recovery fast low-angle shot imaging for T1 mapping, time-resolved angiography with stochastic trajectories for DCE MRI. ASSESSMENT: Dissolved-phase ratios of (129) Xe in red blood cells (RBC), tissue/plasma (TP) and gas phase (GP), ventilation defect percentage, septal wall thickness, surface-to-volume ratio, capillary transit time, lineshape parameters in dissolved-phase spectroscopy, (1) H T1 time, blood volume, flow, and mean transit time were determined and compared to cell counts. STATISTICAL TESTS: Wilcoxon signed-rank test, Pearson correlation. RESULTS: The percentage of neutrophils in sputum was markedly increased after LPS inhalation compared to baseline, P = 0.002. The group median RBC-TP ratio was significantly reduced from 0.40 to 0.31, P = 0.004, and (1) H T1 was significantly elevated from 1157.6 msec to 1187.8 msec after LPS challenge, P = 0.027. DCE MRI exhibited no significant changes in blood volume, P = 0.64, flow, P = 0.17, and mean transit time, P = 0.11. DATA CONCLUSION: Hyperpolarized (129) Xe dissolved-phase MRI and (1) H T1 mapping may provide biomarkers for noninvasive assessment of the response of human lungs to LPS inhalation. By its specificity to the alveolar region, hyperpolarized (129) Xe MRI together with (1) H T1 mapping adds value to sputum analysis. LEVEL OF EVIDENCE: 1 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;51:1669-1676.
- Kern, A. L.
- Biller, H.
- Klimes, F.
- Voskrebenzev, A.
- Gutberlet, M.
- Renne, J.
- Muller, M.
- Holz, O.
- Wacker, F.
- Hohlfeld, J. M.
- Vogel-Claussen, J.
Keywords
- *129Xe MRI
- *T1 mapping
- *dissolved phase
- *inflammation
- *lipopolysaccharide
