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Chengbo Wang¹, Talissa A. Altes¹, ², John P. Mugler, III², G. Wilson Miller², Kai Ruppert¹, ², Jaime F. Mata², Gordon D. Cates, Jr², Larry Borish², Eduard E. de Lange²

¹Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA; ²University of Virginia, Charlottesville, Virginia , USA

Co-registered short-time-scale and long-time-scale hyperpolarized ³He ADC maps were collected in 14 healthy, 14 asthma and 9 COPD subjects.  Compared to the healthy group, the short-time-scale and long-time-scale mean ADC was increased by 9% and 27% (p=0.038 and 0.005) in asthmatics, respectively, and 71% and 117% (p=0.002 and p<0.001) in subjects with COPD, respectively. Regional changes on long-time-scale ADC maps were more conspicuous and more extensive than on short-time-scale ADC maps. Thus, diffusion abnormalities are present in asthmatics, and the long-time-scale ADC appears to have an increased regional sensitivity to these abnormalities.

Dmitriy A. Yablonskiy¹, Alex L. Sukstanskii¹, Jason C. Woods, Andrew J. Bierhals¹, Yulin V. Chang, Richard E. Jacob, Mark S. Conradi, David S. Gierada¹

¹Mallinckrodt Institute of Radiology, St. Louis, Missouri, USA

Numerous measurements of hyperpolarized 3He gas ADC in human lungs indicated substantial changes between healthy and emphysematous lungs. Herein we use the in vivo lung morphometry technique, based on MRI measurement of diffusion of hyperpolarized 3He gas, to identify changes in lung microstructure with emphysema progression. We demonstrate that at the initial stages of emphysema, walls separating alveoli belonging to the same acinar airways are getting destroyed by the disease without substantial effect on inter-airway walls. This follows by destruction of inter-airway walls. We conclude that the In vivo lung morphometry allows non-invasive monitoring emphysema progression at the alveolar level.

Davide Santoro¹, Abram Voorhees², Vinay Pai¹, Igor Kamenetskiy¹, Jean Reid¹, Glyn Johnson¹

¹New York University School of Medicine, New York, USA; ²Siemens Medical Solutions, Inc., Malvern, USA

In this work, a novel method for tracking regional lung motion is applied to provide the local air volume and volumetric flow rate on a voxel scale. The method is based on motion-tracking of the lungs over a series of real-time, hyperpolarized 3He images.

Ryan Kraayvanger¹, ², Chris Bidinosti³, William Dominguez-Viqueria¹, ², Juan Parra-Robles², Matthew Fox¹, ², Wilfred Lam², Giles Santyr, ¹²

¹University of Western Ontario, London, Canada; ²Robarts Research Institute, London, Canada; ³University of Winnipeg, Winnipeg, Canada

Quantitative assessment of alveolar oxygen partial pressure (p_AO₂) in the lung has the potential to become a remarkably useful tool in the diagnosis and monitoring of respiratory disease. It has been demonstrated that p_AO₂ can be measured using the spin-spin relaxation time, T₂, of ³He at very low magnetic field strengths with the Carr-Purcell-Meiboom-Gill (CPMG) sequence. We present relaxivity relationships for oxygen’s effect on ³He and ¹²⁹Xe spin-spin relaxation, in vivo T₂ measurements in rat lung, and test the assertion that T₂=T₁ in the limit of rapid CPMG pulse rates at low magnetic field strength.

Jiangsheng Yu¹, Michelle Law¹, Kiarash Emami¹, Sheeva Rajaei¹, Masaru Ishii, ¹², Stephen Kadlecek¹, Vahid Vadhat¹, John MacDuffie Woodburn¹, Richard A. Guyer¹, Hans Hyonchang Kim¹, Warren Gefter¹, Rahim R. Rizi¹

¹University of Pennsylvania, Philadelphia, Pennsylvania, USA; ²Johns Hopkins University, Baltimore, Maryland, USA

Hyperpolarized 3He MRI has focused primarily on structural and functional aspects of the airspaces. In this work, we present a double-echo acquisition technique for measuring perfusion-induced susceptibility effect. This technique allows automatic co-registration of lung perfusion and ventilation images. In the in-vivo animal experiment, a normal Yorkshire pig (~20kg) was injected with 10mL gadolinium to modify the magnetic susceptibility difference between the lung airway and capillary bed. A susceptibility measurement was performed 10 minutes after the Gd injection. The average phase change caused by this susceptibility difference enhancement (Gd injection) was 57 degrees; while the global mean values of pO2 and R were not affected by the Gd injection.

Nilesh Navnitlal Mistry¹, ², Bastiaan Driehuys², Boma Fubara², William M. Foster², Erin N. Potts², Ben Chen³, Deborah M. Slipetz³, G. Allan Johnson²

¹Duke University, Durham, North Carolina, USA; ²Duke University Medical Center, Durham, North Carolina, USA; ³Merck Frosst Center for Therapeutic Research, Montreal, Canada

Recent high-resolution ³He MRI in mouse models of asthma have provided an opportunity to understand airway biology by depicting regional ventilation changes, and airway narrowing and closure. To maximize the value of ³He MRI, it is important to quantify these ventilation changes visible in the images. In this work, we describe a post-processing scheme to quantify regional ventilation changes before and after MCh challenge; and show that it is sensitive to both changes in airway caliber and subtle regional alterations in ventilation.

François-Xavier Blé¹, ², Stefan Zurbruegg¹, Steve Collingwood³, Henry Danahay³, Nicolau Beckmann¹

¹Novartis Institutes for BioMedical Research, Basel, Switzerland; ²University Louis Pasteur-Strasbourg-1, Illkirch, France; ³Novartis Institutes for BioMedical Research, Horsham, UK

Nebulized hypertonic saline (HS) provides benefit to cystic fibrosis patients. Since the effects of HS are transient, administration of epithelial sodium channel (ENaC) blockers prior to HS is being pursued as strategy to improve the duration of action of HS. Using MRI we followed the fluid dynamics in the lungs of spontaneously breathing rats treated with compounds that interacted with ENaC, administered before HS. As a non-invasive readout of global fluid dynamics in the whole lung in situ, MRI provides complementary information to that obtained using in vitro or ex vivo models currently supporting ENaC-related drug investigations.

Yoshiharu Ohno¹, Tae Iwasawa², Joom Beom Seo³, Hisanobu Koyama¹, Hiroshi Takahashi², Yeon-Mok Oh³, Yoshihiro Nishimura⁴, Kazuro Sugimura¹

¹Kobe University Graduate School of Medicine, Kobe, Japan; ²Kanagawa Cardiovascular and Respiratory Center, Yokohama, Japan; ³University of Ulsan College of Medicine, Seoul, Republic of Korea; ⁴Kobe University Graduate School of Mediciine, Kobe, Japan

O2-enhanced MRI as well as hyperpolarized noble gas MR imaging have been proposed as useful procedures for evaluation of morphological changes or regional pulmonary functional changes.  However, the literature shows no publications dealing with prospective and direct comparison of the capability of quantitatively assessed CT (quantitative CT) and of O2-enhanced MRI for smoking-related functional loss assessment and clinical stage classification of smoking-related COPD.  The purpose of the multi-center trial conducted for this purpose was to prospectively and directly compare the efficacy of O2-enhanced MRI and quantitative CT for smoking-related pulmonary functional loss assessment and clinical stage classification of smoking-related COPD.

Josephine Helen Naish¹, Deirdre M. McGrath¹, Charles E. Hutchinson¹, Lars E. Olsson², John C. Waterton, ¹³, Chris J. Taylor¹, Geoff J. Parker¹

¹University of Manchester, Manchester, UK; ²AstraZeneca, Mölndal, Sweden; ³AstraZeneca, Macclesfield, UK

In this study we demonstrate the feasibility of measuring regional pulmonary vascular endothelial permeability using DCE-MRI. By acquiring and modelling an extended dynamic time series we observe significantly increased vascular permeability in a group of smokers compared with a group of non-smokers. This observation is consistent with the presence of smoking-induced inflammation.