Traditional Posters: Body Imaging

Hyperpolarized Gas Imaging

Hall B Thursday 13:30-15:30

2528. Comparison of Hyperpolarized ³He and ¹²⁹Xe for Measurement of Absolute Ventilated Lung Volume of Rat Lungs

Matthew S. Fox^1,2, Alexei Ouriadov¹, William Dominguez-Viqueira^1,3, Marcus Couch^1,2, Giles E. Santyr<sup>1,3

1</sup>Imaging, Robarts Research Institute, London, Ontario, Canada; ²Physics and Astronomy Dept, University of Western Ontario, London, Ontario, Canada; ³Medical Biophysics, University of Western Ontario, London, Ontario, Canada

Magnetic Resonance (MR) imaging using hyperpolarized noble gases (HNG) ³He and ¹²⁹Xe provides a non-invasive approach for probing both lung function and structure. Measurement of ventilated lung volumes are useful for characterizing chronic obstructive pulmonary disease, quantifying the diffusing capacity of xenon and may be useful in measuring lung mechanics such as compliance. The objective of this work was to perform 3D MR imaging in rats under similar ventilation conditions and compare measured ventilated volumes obtained from the two gases in an effort to show that ¹²⁹Xe is just as accurate as ³He which has already been validated by microCT.

2529. Hyperpolarized Xenon-129 Ventilation MRI: Preliminary Results in Normal Subjects and Patients with Lung Disease

Talissa A. Altes¹, John P. Mugler¹, Isabel M. Dregely², Stephen Ketel³, Iulian C. Ruset^2,3, Eduard E. de Lange¹, F William Hersman^2,3, Kai Ruppert<sup>1

1</sup>Radiology, University of Virginia, Charlottesville, VA, United States; ²Physics, University of New Hampshire, Durham, NH; ³Xemed, LCC, Durham, NH

The purpose of this study was to assess the feasibility and currently achievable quality of hyperpolarized xenon-129 ventilation (spin density) MRI in normal subjects (n=7) and patients with asthma (n=5), chronic obstructive pulmonary disease (COPD) (n=4), cystic fibrosis (CF) (n=1), and sickle cell disease (SCD) (n=1). As seen previously with helium, the normal subjects had homogeneous ventilation with few if any ventilation defects. Focal ventilation defects were found in all patients with obstructive lung diseases. Qualitatively the hyperpolarized xenon-129 ventilation images are similar although not identical to previously acquired hyperpolarized helium-3 ventilation images in different patients with similar disease states.

2530. Synchronised Acquisition of Hyperpolarised 3He and 1H MR Images of the Lungs During the Same Breath-Hold

Jim M. Wild¹, Salma Ajraoui¹, Martin H. Deppe¹, Steven R. Parnell¹, Helen Marshall¹, James Swinscoe², Matthew Hatton², Juan Parra-Robles¹, Rob H. Ireland<sup>1

1</sup>Academic Radiology, University of Sheffield, Sheffield, Yorkshire, United Kingdom; ²Weston Park Hopital, Sheffield, United Kingdom

Combined 1H MRI of lung anatomy with hyperpolarised gas MRI of lung function has previously required acquisition of separate breath-hold exams, with separate MRI pulse sequences and dedicated RF coils, resulting in images that were not spatially registered or temporally synchronised. Here 1H anatomical and 3He ventilation MRI from human lungs were acquired in the same breath-hold using decoupled RF hardware and optimised dual acquisition MRI pulse sequences. The resulting 3He and 1H images acquired in the same breath (from volunteers and patients with lung disease), showed superior registration to those acquired in repeat breath-hold manoeuvres.

2531. Inter-Observer Reproducibility of Longitudinal Hyperpolarized Helium-3 Magnetic Resonance Imaging of Chronic Obstructive Pulmonary Disease