pre-scan preparation and coaching of subject for 129xe mri of lung ventilation

超极化 129Xe MRI 研究肺功能的标准化工作流程

Hyperpolarized 129Xe MRI is an exciting tool for non-invasive, spatially-resolved characterization and quantification of specific aspects of pulmonary function1,2,3. Acquisition and reconstruction approaches similar to those used in anatomical proton MRI yield images of inhaled 129Xe in the lungs, permitting visualization of non-ventilated lung regions and region-resolved quantification of ventilation distribution4,5,6,7,8. More advanced pulse sequence and analysis techniques yield further complementary information, including quantification of gas-exchange efficacy between alveoli and pulmonary capillaries via spectroscopic MRI9,10,11,12,13 and characterization of alveolar microstructure integrity via diffusion-weighted MRI14,15,16.
Inhaled 129Xe has been proven safe and tolerable in adult and pediatric subjects, including those with pulmonary disease17,18. Measurements of lung function derived from 129Xe MRI have shown sensitivity to structural and functional alterations in many pulmonary disease contexts, including chronic obstructive pulmonary disease6,10,19, cystic fibrosis20,21,22, idiopathic pulmonary fibrosis23,24,25, and asthma7,10,26. Given the high safety and tolerability of 129Xe MRI, the lack of ionizing radiation in MRI compared with other common imaging approaches, and the high reproducibility of 129Xe MRI results27,28, 129Xe MRI holds significant promise, in particular for precise serial monitoring of individuals receiving a time course of therapy for chronic pulmonary disease.
The safety and clinical promise of 129Xe MRI have led to its FDA approval in December 2022 for lung ventilation imaging in persons aged 12 years and older29. Given this, it is anticipated that the number of research and clinical sites capable of performing 129Xe MRI (currently ~20 worldwide) will increase significantly over the coming years. As 129Xe MRI spreads to new institutions, it is important that robust methodological resources exist to allow sites to build out clinically relevant 129Xe MRI techniques quickly and to perform scans and generate results that are closely comparable with those of existing sites.
In this work, we will outline the current best practices for human hyperpolarized 129Xe MRI of lung ventilation, as agreed upon by member institutions of the 129Xe MRI Clinical Trials Consortium (Xe MRI CTC) and summarized in a recent position paper30. Topics will include the preparation of tailored pulse sequences ideal for a complete 129Xe MRI workflow, preparation, and administration of hyperpolarized 129Xe gas, an optimized workflow for human 129Xe MRI sessions, and best practices for monitoring subject safety and comfort during MRI sessions.

作者聚焦：使用 129Xe MRI 推进肺部成像的标准化和最佳实践

获取肺通气的超极化 129Xe 磁共振图像

Our research seeks to establish Xenon MRI as a clinical tool for characterizing lung function. Xenon MRI allows us to directly visualize ventilation defects in patients with obstructive lung diseases like COPD, asthma, and cystic fibrosis. It offers information that can't be obtained from standard MRI and pulmonary function test.Xenon MRI was recently approved by the FDA for clinical evaluation of lung ventilation. This represents a culmination of a huge amount of effort by the people in our field and it's an exciting opportunity to show how Xenon MRI can improve patient care and outcomes in pulmonary disease. Xenon MRI is still a relatively new family of techniques, and standardization is still an ongoing process.This protocol distills the existing standards for Xenon ventilation MRI into a form that we hope will be useful to research in clinical sites who are trying to perform these scans for the first time. Common clinical readouts of lung function, like pulmonary function tests, only give a single number for the entire lung with no spatial information included. Xenon MRI can make regional assessments of several aspects of lung health and function, which we believe will be very useful in the clinic.Only a few institutions are currently performing Xenon MRI, but we expect there will be many more sites soon considering the recent FDA approval. We hope that this Xenon ventilation MRI protocol will serve as a blueprint for new sites and help em to ramp up their Xenon MRI operations more quickly.

受试者进行 129Xe 肺通气 MRI 的预扫描准备和指导

首先，准备一个或多个装有空气的 Tedlar 袋，供受试者在扫描仪外练习。使用与实际研究期间从袋子中吸入的氙气和缓冲气体总体积相匹配的空气量。为受试者准备鼻夹，以便在屏气扫描期间佩戴，在开始屏气之前将鼻夹安装在受试者的鼻子上。每次尝试使用一个充气袋来指导受试者。在制作袋子之前，让受试者有规律地吸气和呼气几次。在手术过程中，监测受试者的胸部，以确认他们正在正确执行指令。接下来，将连接到 Tedlar 袋的管子放入受试者的嘴里。握住袋子，使受试者可以从中吸气并打开阀门。让受试者吸气，然后让受试者屏住呼吸，说，屏住呼吸。练习时，等待 10 到 15 秒的计数，这是典型的氙气 129 扫描所需的大致时间。之后，要求受试者此时呼气并呼吸。指导受试者深呼吸几次，以更快地清除肺部的氙气 129，并更快地恢复到正常的氧饱和度水平。验证受试者是否能够可靠地执行指令，并考虑排除在练习期间无法这样做的受试者。

Research

JoVE Journal

Medicine

Pre-Scan Preparation and Coaching of Subject for 129Xe MRI of Lung Ventilation

Acquiring Hyperpolarized 129Xe Magnetic Resonance Images of Lung Ventilation

Hyperpolarized 129Xe MRI comprises a unique array of structural and functional lung imaging techniques. Technique standardization across sites is ...

科研

医学

Preparation of MRI Scanner Room and Subject Positioning for 129Xe MRI of Lung Ventilation

肺通气 129Xe MRI 的 MRI 扫描仪室的制备和受试者定位

Performing 129Xe MRI Scan of Lung Ventilation to Assess Pulmonary Function

进行肺通气 的 129Xe MRI 扫描以评估肺功能