Review of oxygen‐enhanced lung mri: Pulse sequences for image acquisition and T₁ measurement

Abstract

Oxygen‐enhanced MR imaging (OE‐MRI) is a special proton imaging technique that can be performed without modifying the scanner hardware. Many fundamental studies have been conducted following the initial reporting of this technique in 1996, illustrating the high potential for its clinical application. This review aims to summarise and analyse current pulse sequences and T1 measurement methods for OE‐MRI, including fundamental theories, existing pulse sequences applied to OE‐MRI acquisition and T1 mapping. Wash‐in and wash‐out time identify lung function and are sensitive to ventilation; thus, dynamic OE‐MRI is also discussed in this review. We compare OE‐MRI with the primary competitive technique, hyperpolarised gas MRI. Finally, an overview of lower‐field applications of OE‐MRI is highlighted, as relatively recent publications demonstrated positive results. Lower‐field OE‐MRI, which is lower than 1.5 T, could be an alternative modality for detecting lung diseases. This educational review is aimed at researchers who want a quick summary of the steps needed to perform pulmonary OE‐MRI with a particular focus on sequence design, settings, and quantification methods.

Editorial for “Assessment of Pulmonary Ventilation Using 3D Ventilation Flow‐Weighted and Ventilation‐Weighted Maps From 3D Ultrashort Echo‐Time (UTE) MRI”

“…Gas ventilation mapping can occur during both static breath‐hold and dynamic multiple breath washout, 2 but this method inherently requires use of an inhaled contrast agent, specialized devices/equipment, and, at times, breathing maneuvers that may not mimic respiratory mechanics that occur in natural tidal breathing. Oxygen‐enhanced 1 H MRI can assess lung function during tidal breathing via T 1 ‐mapping using an inhaled agent that is readily available and affordable in all hospitals and advantageously does not require scanner hardware modifications; however, oxygen‐enhanced techniques require low spatial resolutions and long scan times in order to provide sufficient signal‐to‐noise ratio (SNR) 3 …”