Proton vs Hyperpolarized-Gas MRI for Evaluating the Lung
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Thursday May 12th
Room 513A-D  10:30 - 12:30 Moderators: Per A.G. Åkeson and Kiarash Emami

10:30 541.   Validation of ventilation- and perfusion-weighted Fourier Decomposition MRI with hyperpolarized 3He-MRI and Dynamic Contrast-Enhanced MRI in an animal experiment 
Grzegorz Bauman1, Alexander Scholz2, Julien Rivoire2, Maxim Terekhov2, Janet Friedrich2, Andre de Oliveira3, Wolfhard Semmler1, Laura M Schreiber2, and Michael Puderbach4
1Division of Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany, 2Department of Radiology, Section of Medical Physics, Johannes Gutenberg University Medical Center, Mainz, Germany, 3Siemens Healthcare, Erlangen, Germany, 4Division of Radiology, German Cancer Research Center, Heidelberg, Germany

Regardless of physical and technical difficulties, MRI offers a broad spectrum of methods for the relative or absolute evaluation of the lung function. Recently, a technique of Fourier decomposition MRI (FD-MRI) was proposed to obtain regional lung perfusion and ventilation-related information during a single acquisition series. FD-MRI is based on a non-invasive, untriggered and contrast media free image acquisitions. The purpose of this study was the validation of this lung functional imaging technique against Dynamic Contrast-Enhanced MRI and hyperpolarized 3He-MRI in an animal experiment under controlled conditions.

10:42 542.   Heterogeneity of the ventilation–perfusion ratio in lung disease using OE-MRI 
Penny Louise Hubbard1,2, Geoff J M Parker1,2, Dave Singh3, Eva Bondesson4, Lars E Olsson5, Lars Wigström5, Simon S Young6, and Josephine H Naish1,2
1Imaging Sciences and Biomedical Engineering, The University of Manchester, Manchester, United Kingdom, 2The Biomedical Imaging Institute, The University of Manchester, Manchester, United Kingdom, 3Airway Pharmacology Group, School of Translational Medicine, University Hospital of South Manchester Foundation Trust, Manchester, Greater Manchester, United Kingdom, 4AstraZeneca R & D, Lund, Sweden, 5AstraZeneca R & D, Möndal, Sweden, 6AstraZeneca R & D, Charnwood, United Kingdom

We present the results of an oxygen-enhanced (OE-) MRI study in subjects with Chronic Obstructive Pulmonary Disease (COPD) and age-matched healthy subjects. Our approach allows quantitative maps of the ventilation-perfusion (V/Q) ratio to be determined using a novel two-compartment physiological model. Dynamic OE-MRI data is acquired whilst the subjects move from breathing medical air to 100% oxygen and back to air. On-air T1 maps reveal higher T1 in healthy subjects and those with COPD. In addition, V/Q maps and histograms reveal significant heterogeneity in COPD and show similarities to work previously published in the SPECT and PET literature.

10:54 543.   Assessment of Relative Regional Lung Compliance in Patients with Chronic Obstructive Pulmonary Disease 
Alexandra Rose Morgan1,2, Geoff J. M. Parker1,2, Penny L. Hubbard1,2, David Singh2,3, Jørgen Vestbo2,3, Simon S Young4, Eva Bondesson5, Lars Wigström5, Lars E Olsson6, Marietta L.J. Scott7, and Josephine H. Naish1,2
1Imaging Science and Biomedical Engineering, University of Manchester, Manchester, Greater Manchester, United Kingdom, 2Biomedical Imaging Institute, University of Manchester, Manchester, Greater Manchester, United Kingdom, 3Airway Pharmacology Group, School of Translational Medicine, University Hospital of South Manchester, Manchester, Greater Manchester, United Kingdom, 4AstraZeneca R&D, Charnwood, United Kingdom, 5AstraZeneca, Lund, Sweden, 6AstraZeneca, Mölndal, Sweden,7AstraZeneca, Alderley Park, Macclesfield, United Kingdom

An MRI method to obtain measures of relative regional compliance and local lung dynamics has been developed. The method utilizes free-breathing proton MRI images and image warping to illustrate regions of altered lung mechanics in disease. The method has been applied in a cohort of healthy volunteers and patients with chronic obstructive pulmonary disease (COPD) with varying disease severity, the results of which are presented here. Clear differences between COPD patients and healthy volunteers could be seen in the majority of cases, with patients exhibiting regions of reduced and asymmetrical lung motion and an increased heterogeneity in relative regional compliance.

11:06 544.   Non-Contrast-Enhanced High Resolution MRI of the Pulmonary Blood Volume Using a Two Compartment Model and T1 Mapping 
Thomas Gaass1,2, Julien Dinkel3, Grzegorz Bauman2, Moritz Zaiss2, Axel Haase1, and Frederik Laun2
1Institute of Medical Engineering, Technical University Munich, Munich, Germany, 2Division of Medical Physics, German Cancer Research Center, Heidelberg, Germany,3Division of Radiology, German Cancer Research Center, Heidelberg, Germany

The accurate assessment of the pulmonary blood distribution is becoming increasingly important for specific diagnostic problems. Since the current standard clinically applied techniques pose an increased patient risk an alternative non-contrast-enhanced MRI method is highly desirable. The introduced novel technique (TCIR) uses a two-compartment model and inversion recovery with alternating inversion times to produce high resolution maps of the fractional pulmonary blood volume. The purpose of this work was to evaluate the reproducibility and sensitivity of TCIR. Comparing TCIR with dynamic contrast enhanced MRI, the feasibility of the proposed technique is additionally shown on a patient.

11:18 545.   Pulmonary Blood Volume Mapping using a Modified T1 Weighted, Steady State MRI Technique in a Rodent Model of Hypoxic Pulmonary Vasoconstriction 
Ronn P Walvick1,2, Austin L Reno2, Alexei A Bogdanov2, and Mitchell S. Albert2
1Radiology, New York University Langone Medical Center, New York, NY, United States, 2Radiology, University of Massachusetts Medical School, Worcester, MA, United States

The purpose of this study was to develop a magnetic resonance imaging (MRI) technique for measurement of pulmonary blood volume (PBV). The proposed imaging technique consisted of acquiring images of lung parenchyma with a cardiac and respiratory gated inversion recovery, T1 weighted spin-echo sequence before and after the injection of a long circulating, intravascular contrast agent. This technique was used to the measure PBV in a rodent model of pulmonary hypoxic vasoconstriction. Results revealed a significant decrease in the PBV in animals breathing gas with low oxygen content. The measured PBV increased with increasing inversion time due to water exchange.

11:30 546.   Acquisition of Spatially-registered Helium-3 and Proton 3D Image Sets of the Lung in less than 10 seconds using Compressed Sensing 
Kun Qing1, Talissa A. Altes2, Nicholas J. Tustison2, Jaime F. Horta Coelho Mata2, Grady W. Miller2,3, Eduard E. De Lange2, William A. Tobias3, Gordon D. Cates3, James R. Brookeman2, and John Philip Mugler1,2
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, 2Radiology, University of Virginia, 3Physics, University of Virginia

Random undersampling combined with compressed-sensing reconstruction permits acquisition of 3D helium-3 and proton data sets, with isotropic 3.9-mm spatial resolution, during a 7-second breath hold. The resulting image quality is very similar to that obtained using a fully-sampled acquisition that requires almost 20 seconds. This capability should be valuable for quantitative assessment of ventilation defects in diseases such as asthma, CF or COPD.

11:42 547.   Highly Accelerated Dynamic 3D Hyperpolarized Lung Imaging 
Sebastian Kozerke1,2, Salma Ajraoui3, Thomas Eykyn4, Reza Razavi4, and Jim M Wild3
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 3Unit of Academic Radiology, University of Sheffield, United Kingdom, 4Division of Imaging Sciences and Biomedical Engineering, King's College London, United Kingdom

Dynamic hyperpolarized helium-3 imaging has been shown to provide assessment of air trapping in obstructive lung disease. A key requirement for imaging ventilation heterogeneity concerns dynamic volumetric coverage of the lung at sufficient spatiotemporal resolution. The present work introduces feedback-regularized k-t PCA for dynamic hyperpolarized gas imaging. It is demonstrated that the synergistic combination of partial Fourier and k-t sampling allows for more than 12-fold net increases in scan efficiency relative to fully sampled 3D lung imaging. In-vivo dynamic 3D data acquired during inhalation and wash-out of hyperpolarized helium-3 gas illustrate the value of the method proposed.

11:54 548.   Pulmonary 3He MRI of Pediatric Subjects with Risk Factors for Asthma 
Robert V. Cadman1, Jionghan Dai1, Michael D Evans2, Daniel J. Jackson3, James E. Gern3, Robert F. Lemanske Jr.3, and Sean B. Fain1
1Medical Physics, University of Wisconsin, Madison, WI, United States, 2Biostatistics and Medical Informatics, University of Wisconsin, Madison, WI, United States,3Pediatrics, University of Wisconsin, Madison, WI, United States

Pulmonary 3He MRI was performed on 9- and 10-year-old subjects who had been enrolled at birth in a longitudinal study of asthma development. Separate diffusion-weighted radial stack-of-stars and 3-dimensional radial dynamic series were acquired for each subject. Root-mean-square diffusion length of 3He was found to correlate with both current asthma diagnosis and history of human rhinovirus infection associated with wheezing illnesses during preschool ages. Ventilation defects observed in dynamic images were correlated with current asthma diagnosis.

12:06 549.   Imaging of Lung Micromechanics with Hyperpolarized Gas Diffusion MRI: Regional Compliance 
Yi Xin1, Kiarash Emami1, Stephen J. Kadlecek1, Puttisarn Mongkolwisetwara1, Nicholas N. Kuzma1, Harilla Profka1, Yinan Xu1, Hooman Hamedani1, Benjamin M. Pullinger1, Rajat K. Ghosh1, Jennia N. Rajaei1, Stephen Pickup1, Masaru Ishii2, and Rahim R. Rizi1
1Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States, 2Otolaryngology–Head & Neck Surgery, Johns Hopkins University, Baltimore, Maryland, United States

Measurements of 3He apparent diffusion coefficient as a function of lung inflation level reveal a more drastic relative increase in regional ADC values at lung pressures above 12 cmH2O in an elastase model of rat emphysema compared to the healthy animals. This altered ADC imaging protocol can potentially serve as a sensitive marker for changes in regional lung compliance induced by lung diseases such as emphysema.

12:18 550.   Quantitative Scoring of Hyperpolarized 129Xe Ventilation Imaging: Correlation with Pulmonary Function Testing and Age 
Bastiaan Driehuys1,2, Zackary I Cleveland1,2, John Nouls1,2, S. Sivaram Kaushik2,3, Gary P. Cofer2, Santiago Jimenez-Martinez1, Jan Wolber4, Monica Kraft5, and H. Page McAdams1
1Department of Radiology, Duke University, Durham, NC, United States, 2Center for in vivo Microscopy, Duke University, 3Biomedical Engineering, Duke University, 4GE Healthcare, 5Pulmonary and Critical Care Medicine, Duke University

As part of a recently completed phase I clinical trial, 44 subjects underwent hyperpolarized (HP) 129Xe ventilation imaging. Here we report quantitative analysis of these129Xe ventilation images using a simple reader-based scoring system. We show that xenon ventilation scores correlate significantly with pulmonary function tests and readily separate subjects with chronic obstructive pulmonary disease (COPD) from age-matched controls. Moreover, in the healthy subject population, we show that defects scores correlate significantly with age, a finding that may suggest that 129Xe, with its high resistance to flow, is more sensitive to minor obstruction than 3He.