Traditional Posters: Body Imaging

Harald E. Möller^1,2, Zackary I. Cleveland², Laurence W. Hedlund², Bastiaan Driehuys<sup>2

1</sup>Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; ²Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States

In experiments involving repeated deliveries of hyperpolarized (HP) gas, the delivered magnetization is not constant due to unavoidable relaxation during HP gas storage. Moreover, the spin-lattice relaxation time, T_1R, inside flexible plastic bags, which often serve as HP gas reservoirs, is not constant. The change of T_1R of HP ¹²⁹Xe in a deflating bag can be quantitatively described by a model based on simple spherical geometry and the kinetic theory of gases to account for relaxation mechanisms in the bulk gas and on the container walls. Results might be used for optimizing signal utilization and improving the point-spread function.

2569. Hyperpolarized ³He Image Feature Analysis in Asthmatics

Nicholas James Tustison¹, Talissa A. Altes², Gang Song¹, Eduard E. de Lange², John P. Mugler III², James C. Gee<sup>1

1</sup>Radiology, University of Pennsylvania, Philadelphia, PA, United States; ²Radiology, University of Virginia, Charlottesville, VA, United States

We analyze features extracted from hyperpolarized helium-3 ventilation images in asthmatic and normal populations and quantify their discriminatory abilities in characterizing clinical diagnosis relative to spirometric features.

2570. Retrospective Bias Correction of Hyperpolarized ³He MRI of the Lung

Nicholas James Tustison¹, Talissa A. Altes², G. Wilson Miller², Eduard E. de Lange², John P. Mugler III², James C. Gee<sup>1

1</sup>Radiology, University of Pennsylvania, Philadelphia, PA, United States; ²Radiology, University of Virginia, Charlottesville, VA, United States

We present an open source bias correction algorithm based on the popular N3 algorithm and demonstrate its superior performance for nonuniform intensity correction in hyperpolarized helium-3 lung images.

2571. Hyperpolarized ³He Magnetic Resonance Image Registration Tools for Longitudinal and Multi-Modality Studies

Lindsay Mathew^1,2, Usaf Aladl¹, Aaron Fenster^1,2, Grace Parraga<sup>1,2

1</sup>Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada; ²Medical Biophysics, The University of Western Ontario, London, Ontario, Canada

Hyperpolarized ³He MRI has shown promise as a treatment planning tool for lung cancer. Current barriers to the application of this technology include a lack of accurate image registration techniques. Registration of longitudinally acquired ³He MRI scans and ³He MRI to CT will allow for both detection of regional changes in lung function, and determination of ventilation defect pathology. In this study accuracy and variability of ³He MRI registration techniques were evaluated from a dataset consisting of subjects scanned longitudinally at our center. The Fiducial Localization Error and Fiducial Registration Error were evaluated as metrics of registration accuracy and precision.

2572. Quantitative Evaluation of Hyperpolarized Gas Retention in the Lungs During Time Resolved 3D MRI