BME.07 – A Xenon MRI Probe for Mouse Lung Imaging

• Safa Hameed
• Enrique Sierra

Hyperpolarized gas lung MRI has shown promising results in generating functional images of subtle physiological changes to help diagnose pulmonary conditions in early stages. Providing higher sensitivity than traditionally performed CT scans, hyperpolarized gas MRI has proven to be an adequate alternative for lung imaging, conveying further insights into disease pathology. 129Xe has been extensively studied as a contrast agent, displaying high solubility in pulmonary tissue and following the same gas exchange pathway as oxygen in the alveoli. To further investigate delicate pathophysiological changes in lung conditions through preclinical studies in mice, MRI technicians and researchers need a surface radiofrequency coil capable of detecting 129Xe. Current probes for similar applications are available for lower frequencies or in volume coil configurations, which have lower signal-to-noise ratio than surface coils. Thus, a single-loop surface radio frequency coil was fabricated to provide electrical resonance at the Larmor frequency of 129Xe is 110.7 MHz in a 9.4 T magnetic field with the ability to tune and match the circuit using trimmer capacitors. To verify the primary function of the radio frequency coil, a vector network analyzer paired with a pick-up loop was used to examine the output frequency of the resonance circuit, and appropriate circuit and overall device design changes were implemented to achieve the target frequency. Future validation testing includes acquiring MR images of 129Xe phantom using the single-loop surface radio frequency coil and co-registering with proton MR images. Due to its heightened sensitivity, results achieved from functional MRI using hyperpolarized 129Xe gas can lead to insights in disease progression and early detection of pulmonary conditions.