Electronic poster

Thursday 13:30-15:30 Computer 93

13:30 4594. Flow Vector Analysis of Portal Venous Flow Using Time-SLIP (Time-Spatial Labeling Inversion Pulse) with an Optical Flow Method

Akiyoshi Yamamoto¹, Riichiro Nagashima¹, Kentaro Haraoka¹, Katsumi Nakamura¹, Mitsue Miyazaki<sup>2

1</sup>Radiology, Tobata Kyoritsu Hospital, Kitakyushu, Fukuoka, Japan; ²Toshiba Medical Research Institute, USA, Vernon Hills, IL, United States

Flow vector analysis using optical flow can provide the useful information to assess portal venous hemodynamics enhancement using Time-SLIP.

14:00 4595. In Vivo ¹H MRS of Gallbladder Bile Using an Optimized 8-Channel Phased Array at 3T: Towards Improved Diagnosis of Hepatopancreatobiliary Diseases

Sanaz Mohajeri^1,2, Tedros Bezabeh¹, Scott B. King¹, Omkar B. Ijare¹, Gerald Y. Minuk³, Jeremy Lipschitz⁴, Ian C.P. Smith<sup>1

1</sup>National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada; ²Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Manitoba, Canada; ³Hepatology, University of Manitoba, Winnipeg, Manitoba, Canada; ⁴Surgery, University of Manitoba, Winnipeg, Manitoba, Canada

Considering the key role of liver in body metabolism, the study of bile composition is of great importance. In vitro ¹H MRS of bile samples have shown diagnostic value in detecting various hepatopancreatobiliary disorders. Given the invasive nature of this procedure, we considered the possibility of gathering in vivo data. We present here our initial efforts to obtain bile spectra from pigs using a 3T clinical scanner comparing the use of a Siemens body array coil with an optimized home-built receive array coil.

14:30 4596. Inhibited Hepatobiliary Excretion Is a Sign of Cholangiocarcinoma in Patients with Primary Sclerosing Cholangitis

Lena M. Hallberg¹, Annika Bergquist², Nils Albiin<sup>1

1</sup>Radiology, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden; ²Gastroenterology and Hepatology, Karolinska University Hospital, Karolinska Insitutet, Stockholm, Sweden

Cholangiocarcinoma is a well known threat to patients with primary sclerosing cholangitis (PSC). Although, early diagnosis is crucial for curative surgical treatment, it is difficult to differentiate malignant strictures from benign. We wanted to see if excretion hepatobiliary contrast was inhibited in affected segments, as a sign of malignancy. Therefore, six patients with PSC and a histopathologically confirmed cholangiocarcinoma , were examined in a 1.5 T MRI and Gd-BOPTA i.v. administered. In five of these patients there was no sign of excretion in affected segments. Thus, inhibited hepatobiliary excretion is a sign of cholangiocarcinoma in patients with primary sclerosing cholangitis.

15:00 4597. Gd-EOB-DTPA Enhanced MR Imaging: Evaluation of Enhancement Effects and Enhancement Patterns in Hepatic Hemangioma

Tsutomu Tamada¹, Atsushi Higaki¹, Akihiko Kanki¹, Satoko Okamoto¹, Katsiyoshi Ito<sup>1

1</sup>Dept. of Radiology, Kawasaski Medical School, Kurashiki-city, Okayama, Japan

We assessed quantitatively and qualitatively the enhancement effects and the enhancement patterns of hepatic hemangioma and normal liver tissue on Gd-EOB-DTPA-enhanced MR imaging. It will be important to know that the dynamic enhancement pattern of hepatic hemangioma is similar to that of hepatocellular carcinoma, probably due to the washout of Gd-EOB-DTPA in the early stage after contrast media administration compared with extracellular Gd chelates.

Lung MRI

Hall B Monday 14:00-16:00 Computer 94

14:00 4598. First Results from Clinical Sitings of a High Production Prototype Xenon Polarizer

F. William Hersman^1,2, Jeff Ketel², Iulian Constantin Ruset, ^1,2, Stephen Ketel², Isabel Dregely¹, Walter Porter², David W. Watt², John P. Mugler, III³, Talissa A. Altes³, Kai Ruppert³, Jaime F. Mata³, Samuel Patz⁴, Hiroto Hatabu⁴, Mirko Hrovat⁵, Iga Muradian⁴, Mikayel Dabaghyan⁴, G. Wilson Miller³, Chengbo Wang³, James P. Butler⁶, Jan H. Distelbrink<sup>2

1</sup>University of New Hampshire, Durham, NH, United States; ²Xemed LLC, Durham, NH, United States; ³University of Virginia, Charlottesville, VA, United States; ⁴Brigham and Women's Hospital, Boston, MA, United States; ⁵Mirtech, Inc, Brockton, MA, United States; ⁶Harvard School of Public Health, Boston, MA, United States

Hyperpolarized xenon-129 is potentially the most viable contrast agent to be used for characterizing pulmonary function by MRI. Further improvements in polarizing technology yield production rates of up to 15 liters/hour with 50% polarization. This high production prototype polarizer was relocated to two clinical sites and demonstrated in pilot clinical studies. First fully engineered systems based on this design, XeBox-E10, will be available in 2010 for collaborative research.

14:30 4599. Producing Hyperpolarized Gases Via Dynamic Nuclear Polarization and Sublimation

Arnaud Comment^1,2, Sami Jannin³, Jean-Noël Hyacinthe⁴, Pascal Miéville³, Riddhiman Sarkar³, Puneet Ahuja³, Paul Romeo Vasos³, Xavier Montet⁴, François Lazeyras⁴, Jean-Paul Vallée⁴, Joseph A. Konter⁵, Patrick Hautle⁵, Ben van den Brandt⁵, Jean-Philippe Ansermet², Rolf Gruetter^1,6, Geoffrey Bodenhausen<sup>3,7

1</sup>Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; ²Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; ³Laboratory of Biomolecular Magnetic Resonance, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; ⁴Department of Radiology, Université de Genève, Genève, Switzerland; ⁵Paul Scherrer Institute, Villigen, Switzerland; ⁶Departments of Radiology, Universités de Lausanne et Genève, Lausanne and Genève, Switzerland; ⁷Department of Chemistry, Ecole Normale Supérieure, Paris, France

A method to produce hyperpolarized gases by dynamic nuclear polarization and subsequent sublimation was designed. The method was illustrated by applications to ¹²⁹Xe in xenon gas, leading to the enhancement of the nuclear magnetic resonance signal-to-noise by four orders of magnitude. The main advantage of this new hyperpolarization method lies in its ability to produce highly polarized gases with large throughputs, on the order of tens of several liters per hour.

15:00 4600. A Dedicated Coil Configuration for Hyperpolarized 129Xe Imaging at 1.5 T

Armin Purea¹, Kevin Teh², Michael Barlow², Dominik Berthel¹, Alexander Weisser¹, Ian Hall³, Peter Morris<sup>2

1</sup>Rapid Biomedical GmbH, Rimpar, Germany; ²Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, United Kingdom; ³IPSET, University of Nottingham, Nottingham, United Kingdom

Presented are preliminary results from a novel coil configuration for 129Xe lung imaging. A non-circular birdcage was used as a transmit coil and a 8 channel receive coil were proposed. The coils were designed to utilise the bore space as much as possible to enhance patient comfort whilst not compromising the image quality. Initial images obtained using a SPGR sequence shows great promise. Scan time for lung patients will potentially decrease with the use of parallel receivers which were designed for optimum signal as much as flexibility.

15:30 4601. 3D Hyperpolarized 3He Imaging of Human Lung with Isotropic Spatial Resolution Using 3D-Cones

Jian-Xiong Wang¹, Alexei V. Ouriadov², Jeffrey A. Stainsby³, Grace E. Parraga², Giles Santyr<sup>2,4

1</sup>Applied Science Laboratory, GE HEALTHCARE, London, ON, Canada; ²Robarts Research Institute, The University of Western Ontario, London, ON, Canada; ³Applied Science Laboratory, GE HEALTHCARE, Toronto, ON, Canada; ⁴Dept. of Medical Biophysics, The University of Western Ontario, London, ON, Canada

A true 3D isotropic spatial resolution imaging method for Hyperpolarized He-3 human lung imaging using 3D-cones sequence is presented. The isotropic voxel size improves accuracy for co-registration, lung volume measurement and analysis for abnormalities in the lung.

Tuesday 13:30-15:30 Computer 94

13:30 4602. Evaluation of Global Surface-To-Volume Ratio of Rabbit Lung Using Hyperpolarized 129Xe Uptake Spectroscopy at 1.5T

Yulin Chang¹, Jaime F. Mata¹, Talissa Altes¹, John P. Mugler III¹, Kai Ruppert<sup>1

1</sup>Radiology, University of Virginia, Charlottesville, VA, United States

Hyperpolarized xenon-129 dissolves into lung tissue and binds hemoglobin and the dissolved-phase (DP) xenon molecules exchange with the gas-phase molecules via diffusion. Therefore the initial rate of the signal replenishment of the DP xenon following a saturation is proportional to both square root of time and lung surface area. In this work we demonstrate the possibility of measuring lung surface-to-volume ratio using DP xenon signals at short delays after a complete saturation in a rabbit model.

14:00 4603. Long-Range Diffusion of Hyperpolarized 3He in Normal and Emphysematous Rat Lungs

Ignacio Rodriguez^1,2, Laura Carrero-Gonzalez, ^1,3, Thomas Kaulisch³, Detlef Stiller³, Jose Manuel Perez-Sanchez⁴, Jesus Ruiz-Cabello<sup>1,2

1</sup>Instituto de Estudios Biofuncionales, Universidad Complutense, Madrid, Spain; ²CIBER de Enfermedades Respiratorias, Madrid, Spain; ³Boehringer Ingelheim Pharma, Biberach an der Riss, Germany; ⁴Univ. Paris-Sud, CNRS, Orsay, France

Using long-range diffusion MRI, ADC of rats with induced emphysema in one lobe has been performed. The results show a statistically significant increase of ADC in the emphysematous lobe at breath-hold, whereas no significant difference is seen at end expiration. Collateral ventilation could play a role in these results. The increase seen at breath-hold agrees with the results found by other workers.

14:30 4604. Comprehensive Pulmonary Evaluation of Emphysematous Mice Using Hyperpolarized ¹²⁹Xe MRI/MRS Under Spontaneous Breathing Mode

Hirohiko Imai^1,2, Atsuomi Kimura², Takuya Kitao², Emi Okubo², Yuki Hori², Satoshi Iguchi², Hideaki Fujiwara<sup>2

1</sup>Center for Advanced Research and Education in Drug Discovery and Development, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan; ²Department of Medical Physics and Engineering, Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan

Several techniques in hyperpolarized ¹²⁹Xe MRI and MRS were applied to spontaneously breathing mice for comprehensively evaluating pulmonary structures and functions in emphysematous mice. The abnormalities of pulmonary structure, perfusion and ventilation were successfully detected in emphysematous mice, while significant difference was not shown in gas exchange. Although further improvement was needed for evaluating gas exchange in spontaneous breathing condition, it was shown that the method described here could become useful for drug research and development using small rodents since this protocol was able to detect several important pathological changes non-invasively.

15:00 4605. Hyperpolarized ³He ADC Measurements: Left-Right and Dorsal-Ventral Differences as a Function of Lung Volume

Ahmed F. Halaweish¹, Daniel R. Thedens¹, Jered P. Sieren¹, Eric A. Hoffman¹, Edwin J.R. vanBeek<sup>1

1</sup>University of Iowa, Iowa City, IA, United States

Hyperpolarized ³Helium MRI Apparent Diffusion Coefficient (ADC) measurements enable probing of the lung microstructure and evaluation of pathological processes that affect airspace size. We successfully evaluated ADC measurements as a function of lung volume in 12 never-smoker subjects across three different lung volumes (20%, 60% & 100%VC). Significant differences between each lung volume were observed, along with significant ventral-dorsal gradients at the 20%VC volume and a more homogenous left-right distribution at 100%VC only. Results suggest that patterns of ADC throughout the lungs in the never-smoker subjects follow proper distribution and ventilation patterns and emphasize the importance of controlled lung inflation.

Wednesday 13:30-15:30 Computer 94

13:30 4606. Dynamic O2-Enhanced MRI Vs. Quantitative Thin-Section MDCT: Capability for COPD Assessment in Smokers

Yoshiharu Ohno^1,2, Hisanobu Koyama¹, Keiko Matsumoto^1,3, Yumiko Onishi¹, Daisuke Takenaka¹, Munebu Nogami¹, Nobukazu Aoyama², Hideaki Kawamitsu², Makoto Obara⁴, Marc van Cauteren⁴, Kazuro Sugimura<sup>1

1</sup>Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; ²Radiology, Kobe University Hospital, Kobe, Hyogo, Japan; ³Radiology, Yamanashi University, Shimokatou, Yamanashi, Japan; ⁴Philips Healthcare, Tokyo, Japan

Direct assessment of signal intensity - time course curve on dynamic O2-enhanced MRI have suggested as having potential for airway abnormality and oxygen transfer assessments. However, the literature shows no publications dealing with direct comparison of the capability of quantitatively assessed thin-section MDCT and of dynamic O2-enhanced MRI for COPD assessment in smokers. We hypothesized that dynamic O2-enhanced MRI may have potential for COPD assessment, and be considered at least as valuable as MDCT in smokers. The purpose of this study was to compare the capability for COPD assessment in smokers between dynamic O2-enhanced MRI and quantitatively assessed thin-section MDCT.

14:00 4607. Oxygen-Enhanced MRI in Patients with Pulmonary Arterial Hypertension: Feasibility and Value

Daniel Maxien¹, Olaf Dietrich², Sven Thieme², Maximilian Reiser², Konstantin Nikolaou<sup>2

1</sup>Department of Clinical Radiology, Ludwig Maximilian University, Munich, Germany; ²Department of Clinical Radiology, Ludwig Maximilian University Munich, Germany

Oxygen-enhanced MRI of the lung has proved its feasibility in studies with healthy volunteers, but till now there is only limited experience in circumscribed patient cohorts. We wanted to determine the value and feasibility of oxygen-enhanced MRI in patients with pulmonary arterial hypertension. Therefore we evaluated the sensitivity and specificity of oxygen-enhanced MRI versus ventilation and perfusion scintigraphy. Furthermore, we made a quantitative comparison of the relative signal enhancement in defect areas with the relative signal enhancement in the whole lung to determine which signal difference is needed for a reliable visual detection of diseased lung areas.

14:30 4608. Improvement of Multislice Oxygen-Enhanced MRI of the Lung by Fully Automatic Non-Rigid Image Registration.

Francesco Molinari^1,2, Grzegorz Bauman³, Monika Eichinger², Bernhard Geiger⁴, Lorenzo Bonomo¹, Hans-Ulrich Kauczor⁵, Michael Puderbach<sup>2

1</sup>Department of Bioimaging and Radiological Sciences, Catholic University of Rome, Rome, Italy; ²Department of Radiology, German Cancer Research Center, Heidelberg, Germany; ³Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany; ⁴Siemens Corporate Research, Princeton, United States; ⁵Department of Radiology, University of Heidelberg, Heidelberg, Germany

In oxygen-enhanced MRI, lung signal is measured repeatedly during different breathing cycles. Inconsistencies of respiratory phase may hamper the quality of the parametric O2-maps. In this study, fully automatic non-rigid registration was assessed as a postprocessing method to improve the quality of O2-MRI of the lung. This post-processing technique reduced spatial misalignment among images and signal variability within the lung. O2-induced signal enhancement was not influenced by image registration. Spatial heterogeneity of parametric O2-maps decreased significantly. As such, fully automatic non-rigid registration appears suitable for improving the quality of multislice O2-MRI of the lung.

15:00 4609. Ultra-Short Echo Time (UTE) MR Imaging of the Lung: Assessment of Tissue Density in the Lung Parenchyma

Masaya Takahashi¹, Osamu Togao¹, Riki Tsuji¹, Ivan Dimitrov<sup>1

1</sup>Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States

The utility of ultra-short TE (UTE) imaging in conjunction with projection acquisition of the free induction decay helps to acquire the MR signal from the lung parenchyma. We applied an UTE sequence for imaging of the murine lung at different positive end-expiratory pressures (PEEP) in a 3 T clinical MRI system. The signal intensity and T2* of the lung parenchyma measured with a UTE sequence reduced as the PEEP became higher where the lung volume increased. We found that both are highly correlated with the lung volume.

Thursday 13:30-15:30 Computer 94

13:30 4610. Automated Airway Lumen Segmentation and Characterization for Use in Patients with Traqueomalacya: A Feasibility Study

Piotr Alfred Wielopolski¹, Pierluigi Ciet², Gabriel Paul Krestin¹, Martin H. Lequin¹, Harm Tiddens³, Rashindra Manniesing<sup>4

1</sup>Radiology, Erasmus Medical Center, Rotterdam, Zuid-Holland, Netherlands; ²Department of Medical-Diagnostic Sciences and Therapies, Policlinico Universitario di Padova, Padova, Italy; ³Department of Pulmonology, Erasmus Medical Center, Rotterdam, Zuid-Holland, Netherlands; ⁴Department of Informatics and Radiology, Erasmus Medical Center, Rotterdam, Zuid-Holland, Netherlands

The purpose of this work was to provide: first, a suitable acquisition scenario including static and dynamic 3D MRI sequences with sufficient temporal and spatial resolution to provide good morphological information and visualization of dynamic events in the central airways and, secondly, to provide the means for an automatic analysis program suitable to segment the airway lumen and a dynamic evaluation of cross-sectional areas of the central airways down to the 2nd generation branching.

14:00 4611. MRI Assessment of Dynamic Lung Volume Changes in Subjects Using a Nasal Expiratory Positive Airway Pressure (NEPAP) Device

Ding Xia¹, Elan J. Grossman¹, D M. Rapoport², I Ayappa², A V. Patel², L Daugherty³, Jian Xu¹, Kelly Anne Mcgorty¹, Qun Chen<sup>1

1</sup>Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, United States; ²Division of Pulmonary and Critical Care Medicine, NYU School of Medicine, New York, United States; ³Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States

The purpose of the current study is to use a real-time MRI technique for measuring lung volume changes caused by using a nasal expiratory positive airway pressure (nEPAP) device, a new treatment for obstructive sleep apnea (OSA). This may help us better understand the mechanism by which it treats OSA. Our results show there is an increase in functional reserve capacity (FRC) while using the nEPAP device. Since end-expiratory hyperinflation is likely to produce increased traction in the trachea, this suggests the main action of the nasal expiratory device may be to stiffen the upper airway through increased longitudinal traction.

14:30 4612. MRI Assessment of Distal Airway Heterogeneity for the Early Detection of Airway Disease with Normal Spirometry

Ding Xia¹, Elan J. Grossman¹, Ke Zhang¹, Abram Voorhees², K I. Berger³, R M. Goldring³, B W. Oppenheimer³, J Reibman³, W N. Rom³, L Rogers³, A Helwig³, L Daugherty⁴, Jian Xu¹, Kelly A. Mcgorty¹, Qun Chen<sup>1

1</sup>Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, United States; ²Siemens Medical Solutions, Malvern, PA, United States; ³Department of Medicine, NYU School of Medicine, New York, United States; ⁴Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States

Clinical-pathologic correlation between patient illness and pulmonary disease is difficult to determine when airway abnormalities are localized only to distal airways of the lungs. The purpose of this study is to establish quantitative regional measurements of heterogeneity for distal airway dysfunction based on a tissue tracking MRI technique and apply them to early diagnosis of obstructive airway disease. Results show that in subjects with suspected distal airway disease MRI indicators of mean regional airflow are reduced despite presentation of normal spirometry. Thus, assessment of regional lung function by MRI may be a useful tool for early detection of airway disease.

15:00 4613. Sensitivity of Viscosity and Elasticity in Preserved Pig Lung by Magnetic Resonance Elastography

Roberta Santarelli¹, Xavier Maître¹, Ralph Sinkus², Luc Darrasse<sup>1

1</sup>Imagerie par Résonance Magnétique et MultiModalités (UMR8081), Univ Paris-Sud, CNRS, Orsay, France; ²Institut Langevin (UMR 7587), ESPCI, Univ Denis Diderot, CNRS, Paris, France

Viscoelastic properties of lungs participate in the organ basic function. Their exploration in vivo is not attainable. Hyperpolarised helium-3 MR-elastography on lungs has been demonstrated in vivo. This new technique ex vivo quantitatively evaluated the comparison between helium-3 and hydrogen MRE: the fluid/structure coupling was found to be strong, validating helium-3 lung MRE as a consistent tool for lung exploration. This work focuses on viscoelastic properties behaviour of hydrogen MRE, applied on the preserved pig lung inflated at different volumes: performance of wavelength, elasticity, and viscosity distribution is discernible throughout the inner area and the outer peripheries of the lungs