Crémillieux Yannick, Montigaud Yoann, Bal Clémence, Pinaud Noël, Pham Vi, Perinel Sophie, Natuzzi Marco, Lux François, Tillement Olivier, Ichinose Nobuyasu, Zhang Bei, Pourchez Jérémie
Institut des Sciences Moléculaires, Université de Bordeaux, Bordeaux, France.
Mines Saint-Etienne, Univ Lyon, Univ Jean Monnet, INSERM, U 1059 Sainbiose, Centre CIS, Saint-Etienne, France.
Magn Reson Med. 2020 May;83(5):1774-1782. doi: 10.1002/mrm.28041. Epub 2019 Oct 25.
The objective of this study is to evaluate the suitability and performance of ultra-short echo time (UTE) sequences for imaging and quantifying the deposition of nebulized MRI contrast agents in human-sized lungs.
Nebulization of clinically used contrast agent or gadolinium-based nanoparticles were performed using a commercial jet nebulizer in isolated and ventilated porcine lungs connected to a 3D-printed human upper airways replica. MR images of isolated lungs were acquired on a 3T clinical MR scanner using 3D UTE sequences at different flip angles.
3D acquisitions with isotropic millimetric resolution were obtained in less than 4 min. Images exhibit homogeneous and large MR signal enhancement (above 200%) following nebulization of both types of aerosols. Deposition of aerosol down to the level of the bronchi of secondary lobules was visualized. T values and the concentration of nanoparticles obtained by MRI were found to correlate with the amount of nebulized gadolinium ions.
The distribution of aerosolized gadolinium-based contrast agent or nanoparticles can be visualized and quantified using UTE MRI in large animal ventilated lung model on a clinical MRI scanner. This protocol can be used for assessing and quantifying aerosol regional deposition with high spatial resolution (1 mm 3D isotropic) without ionizing radiation and could be applied in the future for diagnostic or therapeutic applications in patients.
本研究的目的是评估超短回波时间（UTE）序列在对人体大小肺部雾化磁共振成像造影剂沉积进行成像和定量分析方面的适用性和性能。
使用商用喷射雾化器，在连接到3D打印的人体上呼吸道模型的离体且通气的猪肺中，对临床使用的造影剂或基于钆的纳米颗粒进行雾化。在3T临床磁共振扫描仪上，使用不同翻转角的3D UTE序列采集离体肺的磁共振图像。
在不到4分钟的时间内获得了各向同性毫米级分辨率的3D图像。两种类型的气溶胶雾化后，图像均显示出均匀且大幅的磁共振信号增强（超过200%）。可观察到气溶胶沉积直至次级小叶支气管水平。通过磁共振成像获得的T值和纳米颗粒浓度与雾化钆离子的量相关。
在临床磁共振扫描仪上，使用UTE磁共振成像可在大型动物通气肺模型中可视化并定量分析雾化的基于钆的造影剂或纳米颗粒的分布。该方案可用于以高空间分辨率（1mm各向同性3D）评估和气溶胶区域沉积定量分析，且无需电离辐射，未来可应用于患者的诊断或治疗。
