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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. [ABSTRACT FROM AUTHOR]

Purpose To evaluate the test performance of perfusion-weighted Fourier-decomposition (pw-FD) magnetic resonance imaging (MRI) in comparison to dynamic contrast-enhanced (DCE)-MRI as a reference standard in patients with known or suspected chronic pulmonary embolism (PE). Materials and Methods In 64 patients, chronic PE was ruled out or confirmed by DCE-MRI using a time-resolved angiography with stochastic trajectories (TWIST) sequence in one breath-hold. Pw-FD-MRI was performed using a 2D fast low-angle shot (FLASH) sequence in free-breathing. After a nonrigid image registration, FD was applied to generate pw-images. Lungs were scored by two radiologists (2 and 12 years of lung MRI experience) visually for each lobe and segment for hypoperfused areas. For intra- and interobserver variability, the MR images were analyzed 2 months after the first analysis, blinded to the results of the first reader. Results PE was diagnosed by DCE-MRI in 39 patients. For the pw-FD MRI sensitivity, specificity, accuracy, and positive and negative predictive value for diagnosis of PE were 100%, 95%, 98%, 98%, and 100% on a per-patient basis, 94%, 94%, 94%, 95%, 94% on a per-lobe basis, and 82%, 92%, 88%, 88%, 88% on a segmental basis, respectively. Detection of subsegmental and segmental hypoperfusion using pw-FD MRI showed a moderate agreement with DCE-MRI (kappa of 0.68; 95% confidence interval: 0.64; 0.72). Conclusion Pw-FD of the lung is a feasible test to diagnose chronic PE on a per-patient level during free-breathing without the use of ionizing radiation or contrast agents. J. Magn. Reson. Imaging 2015;42:72-79. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Purpose To evaluate the reproducibility of oxygen-enhanced magnetic resonance imaging (MRI), and the influence of different gas delivery methods, in a clinical environment. Materials and Methods Twelve healthy volunteers were examined on two visits with an inversion recovery snapshot fast low angle shot sequence on a 1.5 T system. Coronal slices were obtained breathing room air as well as 100% oxygen with a flow rate of 15 L/min. For oxygen delivery a standard nontight face mask and a full closed air-cushion face mask were used. T1 relaxation times and the oxygen transfer function (OTF) were calculated. Results The mean T1 values did not change significantly between the two visits ( P > 0.05). The T1 values breathing 100% oxygen obtained using the full closed mask were significantly lower (1093 ± 38 msec; P < 0.05) compared to the standard mask (1157 ± 52 msec). Accordingly, the OTF was significantly higher for the full closed mask ( P < 0.05). The OTF changed significantly on the second visit using the standard mask ( P < 0.05). The full closed mask showed lower interindividual variation for both the T1 values (3.5% vs. 4.5%) as well as the OTF (12.4% vs. 22.0%) and no difference of the OTF on the second visit ( P > 0.05). Conclusion Oxygen-enhanced T1 mapping MRI produces reproducible data when using a full closed face mask. J. Magn. Reson. Imaging 2015;41:60-66. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Keratinocytes and activated T cells interact in skin inflammation by virtue of chemokines and cytokines. T cell-derived IL-17 has been described to play an important role in the course of psoriatic inflammation. In this study, we addressed how keratinocytes influence the secretion of IL-17 in autologous T cell subsets. We found that a co-culture of autologous keratinocytes and T cell-receptor-stimulated T cells markedly enhanced the production of IL-17. Besides the importance of direct cell contact, this effect was mainly mediated by IL-1 and could be blocked by the IL-1 antagonist anakinra. An additional increase in IL-17 production by IL-23 was only seen in the presence of IL-1, which thus plays a permissive role for the action of IL-23. Importantly, co-culture of keratinocytes with CCR6+ CD4+ T cells that are enriched for Th17 cells resulted in significantly higher IL-17 production compared to co-culture with CD4+ T cells. [ABSTRACT FROM AUTHOR]