129xe hyperpolarization and assessment of polarization loss during transport

Hochwertige hyperpolarisierte Xenon-129-Magnetresonanzbilder erhalten

For over a century, lung function assessment has primarily relied on global measurements from spirometry and body plethysmography. However, these traditional pulmonary function tests (PFTs) are limited in their ability to capture early-stage disease&#39;s regional nuances and subtle changes in lung tissue1. Nuclear medicine with inhaled radiotracers has been used widely for the assessment of ventilation/perfusion mismatches commonly associated with pulmonary emboli, but this involves ionizing radiation and yields lower resolution. In contrast, computed tomography (CT) has emerged as the gold standard for lung imaging, offering exceptional spatial and temporal clarity compared to nuclear imaging2. While low-dose CT scans can mitigate radiation exposure, potential radiation risk should still be considered3,4. Proton MRI of the lung is uncommon due to low tissue density of the lung and rapid signal decay from lung tissue, although recent advances offer functional information despite potential low signal. On the other hand, hyperpolarized xenon magnetic resonance imaging (HP 129Xe MRI) is a non-invasive modality that allows for imaging of lung function with regional specificity5,6. It produces a high nonequilibrium nuclear magnetization of the gas in liter quantities. The inert gas is then inhaled by a subject inside the MR scanner for a single breath and is directly imaged by the scanner. Thus, the inhaled gas is directly imaged as opposed to the tissue itself. This technique has been used to assess lung ventilation across many diseases, including asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis, idiopathic pulmonary fibrosis, coronavirus disease 2019 (COVID-19), and many others3. In December 2022, HP 129Xe MRI was approved by the United States FDA as an MRI ventilation contrast agent to be used in the United States of America (USA) in adults and pediatric patients aged 12 years and older7. Physicians can now use 129Xe MRI to better care for patients with improved/personalized treatment plans.
Historically, clinical MRI focuses exclusively on imaging hydrogen nuclei (protons) which are abundant in nearly all human viscera. The MRI scanners, sequences, and quality control are generally maintained by the scanner manufacturer as part of the site license and warranty. However, 129Xe requires a multinuclear capable MR scanner and has required a dedicated research team to operationalize the hyperpolarizer, custom-built radiofrequency (RF) coils, dedicated pulse sequences, and offline reconstruction/analysis software. Each of these components can be supplied by third-party vendors or developed in-house. Thus, the burden of quality control generally rests on the 129Xe research team as opposed to the scanner manufacturer or individual third party. Consistent acquisition of high-quality 129Xe data is therefore uniquely challenging as each component of the 129Xe MRI process introduces the potential for error, which must be closely monitored by the 129Xe team. Not only can these situations be extremely frustrating as researchers have to troubleshoot and investigate possible causes for any challenges that may have arisen, but they can be very costly as this slows down patient imaging and subject recruitment. Some costs associated with troubleshooting involve MRI time costs, the hyperpolarization of 129Xe, which involves the consumption of different gases, and the use of materials. Additionally, with the recent FDA approval and growth in 129Xe imaging, providing a standardized protocol for quality control is necessary to avoid common issues and setbacks in 129Xe operation8,9.
Here, we present some of the more commonly encountered issues in 129Xe MRI, including RF coil failures, the emergence of various noise profiles that lead to low signal-to-noise ratio (SNR), and poor quality images10. We aim to provide some concise quality control (QC) guidelines and protocols to ensure the acquisition of high-quality image data and troubleshoot some of the more common issues that can arise in 129Xe MRI. The insights provided here are also relevant for hyperpolarized helium-3 troubleshooting.

Autor im Rampenlicht: Verwendung von hyperpolarisierter Xenon-129-MRT zur Untersuchung von Lungenerkrankungen 

Fehlersuche und Qualitätssicherung in der hyperpolarisierten Xenon-Magnetresonanztomographie: Werkzeuge für eine hochwertige Bildaufnahme

Watch this Scientific Journal Video about 129Xe Hyperpolarization and Assessment of Polarization Loss During Transport at JoVE.com

129Xe Hyperpolarization and Assessment of Polarization Loss During Transport  

Nr. 129Xe Hyperpolarisation und Bewertung des Polarisationsverlustes während des Transports

Stellen Sie zunächst sicher, dass der XENON 129 Hyperpolarisator gemäß den Richtlinien des Herstellers eingerichtet und betriebsbereit ist. Als Nächstes verwenden Sie NMR an der Hyperpolarisations- oder HP-Messstation, um T1-Relaxationsmessungen an einer repräsentativen HP Xenon 129-Gasprobe durchzuführen. Sorgen Sie für einen direkten und effizienten Weg von der Xenon-Sammelstelle zum Magnetraum, der für die Bildgebung vorgesehen ist, um Verzögerungen während des Xenon-Transports zu minimieren.Messen Sie die anfängliche Äquivalentdosis (DE) des hyperpolarisierten Gases Xenon 129 vor dem Transport anhand der angezeigten Gleichung. Vermeiden Sie fremde Hochfrequenzsignale entlang der Route, da sie zum Polarisationsverlust beitragen können. Nach Beendigung der Rundreise durch den Transport des Gases von der Messstation in die Magnetbohrung und dann auf dem gleichen Weg zurück zur Polarimetriestation.Messen Sie DE erneut, um den zu erwartenden Signalverlust während des Gastransports zu quantifizieren.

129xe-hyperpolarization-assessment-polarization-loss-during

Research

JoVE Journal

Bioengineering

129Xe Hyperpolarization and Assessment of Polarization Loss During Transport

104 Aufrufe. Stellen Sie zunächst sicher, dass der XENON 129 Hyperpolarisator gemäß den Richtlinien des Herstellers eingerichtet und betriebsbereit ist. Als Nächstes verwenden Sie NMR an der Hyperpolarisations- oder HP-Messstation, um T1-Relaxationsmessungen an einer repräsentativen HP Xenon 129-Gasprobe durchzuführen. Sorgen Sie für einen direkten und effizienten Weg von der Xenon-Sammelstelle zum Magnetraum, der für die Bildgebung vorgesehen ist, um Verzögerungen während des Xenon-Transports z...

Serie: 129Xe Hyperpolarization and Assessment of Polarization Loss During Transport  

Troubleshooting and Quality Assurance in Hyperpolarized Xenon Magnetic Resonance Imaging: Tools for High-Quality Image Acquisition

Hyperpolarized (HP) xenon magnetic resonance imaging (129Xe MRI) is a recently federal drug administration (FDA)-approved imaging modality that produces high-resolution images of an inhaled breath of xenon gas for investigation of lung function. However, implementing 129Xe MRI is uniquely challenging as it requires specialized hardware and equipment for hyperpolarization, procurement of xenon imaging coils and coil software, development and compilation of multinuclear MR imaging sequences, and reconstruction/analysis of acquired data. Without proper expertise, these tasks can be daunting, and failure to acquire high-quality images can be&#160;frustrating, and expensive. Here, we present some quality control (QC) protocols, troubleshooting practices, and helpful tools for129Xe MRI sites, which may aid in the acquisition of optimized, high-quality data and accurate results. The discussion will begin with an overview of the process for implementing HP 129Xe MRI, including requirements for a hyperpolarizer lab, the combination of 129Xe MRI coil hardware/software, data acquisition and sequence considerations, data structures, k-space and image properties, and measured signal and noise characteristics. Within each of these necessary steps lies opportunities for errors, challenges, and unfavorable occurrences leading to poor image quality or failed imaging, and this presentation aims to address some of the more commonly encountered issues. In particular, identification and characterization of anomalous noise patterns in acquired data are necessary to avoid image artifacts and low-quality images; examples will be given, and mitigation strategies will be discussed. We aim to make the 129Xe MRI implementation process easier for new sites while providing some guidelines and strategies for real-time troubleshooting.

Here, we present a protocol for obtaining high-quality hyperpolarized xenon-129 magnetic resonance images, covering hardware, software, data acquisition, sequence selection, data management, k-space utilization, and noise analysis.

Hyperpolarized (HP) xenon magnetic resonance imaging (129Xe MRI) is a recently federal drug administration (FDA)-approved imaging modality that produces ...

Forschung

Biotechnik

Performing 129Xe Spectroscopy and Hyperpolarized 129Xe Imaging for Quality Control at 129Xe MRI Sites

Performing 129Xe Spectroscopy and Hyperpolarized 129Xe Imaging for Quality Control at 129Xe MRI Sites  

Durchführung von 129xe-Spektroskopie und hyperpolarisierter 129xe-Bildgebung zur Qualitätskontrolle an 129xe-MRT-Stellen