preparation of mri scanner room and subject positioning for 129xe mri of lung ventilation

肺機能を研究するための過分極 129Xe MRIの標準化されたワークフロー

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.

著者スポットライト: 129Xe MRIを使用した肺イメージングの進歩のための標準化とベストプラクティス

肺換気の過偏波 129Xe磁気共鳴画像の取得

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.

129Xe MRI肺換気のためのMRIスキャナー室の準備と被験者の位置決め

まず、MRIスキャナー室に入る人は、身体やポケットからすべての金属物や電子物を取り除いてください。Xenon 129ベストコイルをスキャナーに接続し、MRIスキャナーの患者テーブルに置いて準備します。スキャナー室のレイアウトに応じて、足が先または頭が先の仰臥位で患者台に横になるように被験者に指示します。必要に応じて、被験者の頭や膝などの下に枕を置き、処置中の快適さを確保します。キセノン129ベストコイルを被験者の胸の周りに固定し、被験者が快適な膨張レベルにあるときに、頭足方向のコイルの正中線を被験者の肺の予想される正中線にできるだけ近づけます。コイルを被験者のローに配置すると、肺の末梢で望ましくない信号が低下する可能性があります。MRIスキャナー室の患者テーブルの隣にMRI安全パルスオキシメータを設置し、パルスオキシメータプローブを被験者に接続します。パルスオキシメータが正しく読み取っていることを確認します。被験者の鼻に鼻カニューレを置き、必要に応じて用量吸入後に使用する酸素源に接続します。酸素ボンベとレギュレーターは、地域の安全ポリシーに基づいてMRIの安全な方法で、到達可能な距離内に配置してください。患者テーブルをMRIスキャナーに進め、コイルまたは被験者の肺の正中線をスキャナーの等中心に合わせます。ここに示されている画像は、損傷したケーブルでキセノン129ベストコイルを使用して無意識のうちに実施された研究の換気画像を表しています。右肺は左肺よりも低い信号対雑音比を示します。キセノン129ベストコイルを被験者の足元に近づけて実施した研究の換気画像をここに示します。人為的に低いキセノン129信号は、受信器の感度が不足しているため、両方の肺頂で観察されます。

Research

JoVE Journal

Medicine

Preparation of MRI Scanner Room and Subject Positioning 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 ...

医学

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

肺換気の 129Xe MRIのための被験者のスキャン前準備とコーチング

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

肺機能を評価するための肺換気の 129Xe MRIスキャンの実行