Lung Imaging
Monday 20 April 2009
Room 316A 11:00-13:00


 Bastiaan Driehuys and Tessa Sundarem Cook

11:00  3.

Young Investigator Award Finalist: Three Dimensional Imaging of Ventilation Dynamics in Obstructive Lung Disease

    James H. Holmes1, Rafael L. O'Halloran1, Ethan K. Brodsky1,2, Thorsten A. Bley2, Christopher J. Francois2, Julia V. Velikina1, Ronald L. Sorkness3, William W. Busse3, Sean B. Fain1,2
1Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA; 2Department of Radiology, University of Wisconsin-Madison, Madison, WI, USA; 3Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA
    Whole-lung 3D imaging of respiration dynamics and gas trapping in asthma is demonstrated using hyperpolarized He-3 gas in combination with an accelerated data acquisition and constrained reconstruction. This technique enables the acquisition of a wealth of information on inflow and exhalation kinetics as well as breathhold ventilation defects, while readily accommodating individual patients’ breathhold capabilities, all within a single comprehensive maneuver. Volunteer studies show agreement with plethysmography and MDCT. However, an advantage of this technique is that it enables regional depiction of dynamic gas trapping in a setting more comparable to a spirometry maneuver, unlike MDCT.
11:20 4. Single Acquisition Time-Resolved T2* Mapping in Lungs Using HYPR 3He MRI
    Katarzyna Cieslar1, Achraf Al Faraj1, Sophie Gaillard1, Yannick Crémillieux1
Université de Lyon, CREATIS-LRMN, UMR CNRS 5220 INSERM U630, Lyon, France

Local T2* measurement of HP 3He in the lung can serve as a potential diagnostic biomarker of tissue microstucture changes. Standard T2* mapping protocol at different lung inflation state involves multiple gas inhalations. In this study, T2* mapping protocol combining HYPR reconstruction and spontaneous breathing ventilation was implemented. The protocol, validated on rats, was designed for single acquisition of multiple echo time ventilation images obtained at different inflation states of the lung. The variations of T2* measured at different breathing phases at tidal volume demonstrate the sensitivity of the technique for detecting changes in the 3He physical environment.

11:32   5.

Single Breath-Hold 3D Q-Space Imaging of Lung Structures Using He-3 MRI

    Rafael Luis O'Halloran1, James H. Holmes1,2, Yu-Chien Wu3,4, Andrew L. Alexander1, Sean B. Fain1,4
Medical Physics, University of Wisconsin, Madison, WI, USA; 2Applied Science Laboratory, GE Healthcare, Waukesha, WI, USA; 3Waisman Laboratory for Brain Imaging and Behavior, University of Wisconsin, Madison, WI, USA; 4Radiology, University of Wisconsin, Madison, WI, USA
    A 3D undersampled stack-of-stars q-space MRI acquisition using hyperpolarized helium-3 was performed in asthmatic adults (n=10), healthy adults (n=4), and healthy children (n=3). Q-space data were fit to a Gaussian function providing maps of the mean structure size. The mean structure size in the adult subjects was 333 ± 23 µm, while the structure size in the children was 312 ± 9 µm agreeing with the known age dependence of lung structure size. The acquisition was also performed in a healthy volunteer at three inhalation volumes. Structure size was observed to increase with lung volume.
11:44  6. In Vivo Lung Elastography with Hyperpolarized Helium-3 MRI

Xavier Maître1, Ralph Sinkus2, Roberta Santarelli1, Mathieu Sarracanie1, Rose-Marie Dubuisson1, Emeline Boriasse1, Emmanuel Durand1, Luc Darrasse1, Jacques Bittoun1
1Unité de Recherche en Résonance Magnétique Médicale (UMR8081), Univ Paris-Sud, CNRS, Orsay, France; 2Laboratoire Ondes et Acoustique (UMR 7587), ESPCI, Univ Denis Diderot, CNRS, Paris, France

    The viscoelastic properties of human tissue depend on its structures, biological conditions, and related pathologies. In the lung parenchyma, these properties participate in the basic function of the organ. They are dramatically altered by diseases like cancer, emphysema, asthma, or interstitial fibrosis. Besides tactual exploration, there is no other non-invasive technique to assess such changes. This work aims to produce a novel measurement tool based on magnetic resonance imaging of hyperpolarised helium-3 to monitor the mechanical properties of the lung, which allow mapping of its compliance and relating it to pathology. We demonstrate its feasibility in vivo.
11:56 7. Compressed Sensing for Hyperpolarized 3He 3D ADC Measurements
    Lise Vejby Søgaard1, Torsten Dorniok1, Frederik Hengstenberg1,2, Sergei Karpuk3, Jørgen Vestbo2, Per Åkeson1, Peter Magnusson1
Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital, Hvidovre, Denmark; 2Department of Cardiology and Respiratory Medicine, Copenhagen University Hospital, Hvidovre, Denmark; 3Institute of Physics, University of Mainz, Germany

The feasibility of applying compressed sensing methods to hyperpolarized 3He apparent diffusion coefficient measurements was investigated. Fully sampled 3D k-space data from one healthy subject and three COPD patients were undersampled and reconstructed by compressed sensing methods. We expect that the method can be used to either decrease scan time (breath-hold) or increase spatial resolution which will be especially important in longitudinal studies of lung disease progression.

12:08 8.

Parallel Acquisition as a Key for Rapid High Resolution 3He-ADC Imaging

    Maxim V. Terekhov1, Julien Rivoire1, Florian M. Meise1, Davide Santoro1, Wolfgang G. Schreiber1
Department of Diagnostic and Interventional Radiology, Section of Medical Physics, Mainz University Medical School, Mainz, Germany
    Apparent Diffusion Coefficient (ADC) of hyperpolarized 3He-gas in lungs is a proven method of non-invasive probing the integrity of the lung’s microstructure. The essential problem of efficiency of 3He-ADC-imaging as the diagnostic tool is the poor localisation of integrity defects due to low spatial resolution of ADC-maps. The purpose of current work is to demonstrate the possibilities, provided by the phased-array parallel acquisition (32ch) for improving the efficiency of 3He ADC-measurements including creating full-3D ADC-maps. The second important task is making comparison of different methods of reconstruction the undersampled imaging datasets (e.g. mSENSE and GRAPPA) to get optimal quality ADC-image.
12:20 9. Compartment-Selective XTC MRI at 1.5T and 3T
    Kai Ruppert1, Yulin Chang1, Talissa A. Altes1, Isabel M. Dregely2, Stephen Ketel3, Iulian C. Ruset2,3, Jaime F. Mata1, F William Hersman2,3, John P. Mugler III1
Radiology, University of Virginia, Charlottesville, VA, USA; 2Physics, University of New Hampshire, Durham, NH, USA; 3Xemed LLC, Durham, NH, USA
    Hyperpolarized xenon-129 spectroscopy has revealed at least two dissolved-phase compartments in the lung: xenon bound to hemoglobin and xenon dissolved in lung tissue and blood plasma. In this work we demonstrate the feasibility of obtaining gas-phase depolarization maps in humans using Xenon polarization Transfer Contrast (XTC) MRI by selectively inverting the magnetization in one of the two compartments. Preliminary results at 1.5T and 3T are presented. These findings will considerably increase the specificity of XTC MRI for the detection of pathological lung function changes.
12:32  10. Non-Contrast Enhanced MRI of Lung Perfusion and Ventilation by Fourier Decomposition
    Grzegorz Bauman1, Michael Puderbach2, Michael Deimling3, Vladimir Jellus3, Christophe Chefd'hotel4, Hans-Ulrich Kauczor5, Lothar Schad6
1Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany; 2Department of Radiology, German Cancer Research Center, Heidelberg, Germany; 3Siemens Healthcare, Erlangen, Germany; 4Siemens Corporate Research, Princeton, NJ, USA; 5Department of Diagnostic Radiology, University Hospital Heidelberg, Heidelberg, Germany; 6Computer Clinical Assisted Medicine, University of Heidelberg, Mannheim, Germany
    We showed the feasibility and reproducibility of a novel approach for non-contrast enhanced perfusion and ventilation assessment in proton MRI. The Fourier Decomposition method was implemented on a 1.5T clinical MR scanner and applied in a healthy volunteer study. A fast steady-state free precession (SSFP) pulse sequence was used to produce 2D time-resolved data stacks. Non-rigid image registration and spectral analysis of the data allowed separating the signal from the lung parenchyma and pulsative blood to generate ventilation and perfusion maps. The presented method requires only minimal patient compliance and is not dependent on triggering techniques.
12:44 11.

Ultra-Short Echo Time (UTE) MR Imaging of the Lung: Comparison  Between Normal and Emphysematous Mice

    Masaya Takahashi1, Osamu Togao1, Makoto Obara2, Marc van Cauteren2, Yoshiharu Ohno3, Craig Malloy1, Makoto Kuro-o4, Ivan Dimitrov1,5
Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA; 2Philips Electronics Japan, Tokyo, Japan; 3Radiology, Kobe University Graduate School of Medicine, Hyogo, Japan; 4Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA; 5Philips Medical Systems, Cleveland, OH, USA
    The recent development of techniques has made possible detailed, non-invasive imaging of pulmonary parenchyma. The utility of ultra-short TE (UTE) imaging in conjunction with projection acquisition of the free inducting decay helps to acquire the MR signal from the lung parenchyma. It allows us to reduce TE up to less than 100 µsec to minimize signal decay caused by short T2 relaxation time, and brings high SNR rather than a conventional FFT short echo image sequence. Here we report our measure of short T2 relaxation time of the lung in the wild-type and emphysematous mice using three-dimensional UTE imaging.