ISMRM 21st Annual Meeting & Exhibition 20-26 April 2013 Salt Lake City, Utah, USA

Body Perfusion & Contrast Agents
Thursday 25 April 2013
Room 155 EF  16:00 - 18:00 Moderators: Peter Caravan, Brian A. Hargreaves

16:00 0742.   Liver Perfusion Quantification with MR-DCE Imaging at 3.0 T for Liver Fibrosis Assessment in Patients with Chronic Liver Diseases
Benjamin Leporq1, Frank Pilleul1,2, Jerome Dumortier3, Olivier Guillaud3, Thibaud Lefort2, Sdika Michaël1, and Olivier Beuf1
1CREATIS; CNRS UMR 5220; INSERM U1044; INSA-Lyon; UCBL, Université de Lyon, Villeurbanne, Rhône-Alpes, France, 2CHU Edouard Herriot; Department of digestive imaging, Hospices Civils de Lyon, Lyon, Rhône-Alpes, France, 3CHU Edouard Herriot; Department of Hepatology, Hospices Civils de Lyon, Lyon, Rhône-Alpes, France

Liver fibrosis is an important cause of mortality and morbidity in patients with chronic liver diseases. While an early detection and a clinical follow-up of liver fibrosis are required for therapeutic strategies, the actual gold standard cannot be used in the clinical follow-up due to inherent risk, interobserver variability and sampling errors. Our objective was to validate a MR protocol at 3.0 T for liver perfusion quantification using MR-DCE imaging with an auto-calibrated procedure for tracer concentration quantification. Validation was performed in-vivo on a prospective study including fourteen patients with chronic liver diseases. Results demonstrated that to quantify liver perfusion using MR-DCE imaging can be achieve at 3.0T. Quantitative perfusion parameters such as HPI, MTT, portal and total perfusion could be relevant biomarkers to make the distinction between the absence of fibrosis, non-advanced fibrosis, and advanced fibrosis in patients with chronic viral hepatitis as well as in patients with NAFLD.

16:12 0743.   The Impact of Dixon Fat Suppression on Liver T1 and DCE Perfusion Quantification
Yuan Le1, Fatih Akisik1, Brian M. Dale2, Karen Koons1, and Chen Lin1
1Radiology and Imaging Science, Indiana University School of Medicine, Indianapolis, IN, United States, 2MR R&D, Siemens Medical Solutions, Morrisville, North Carolina, United States

The presence of fat signal affects both T1 and contrast concentration estimation that in turn can cause error in perfusion quantification from dynamic contrast enhanced (DCE) MRI acquisitions, which are often performed without fat suppression. In this study, we compared the perfusion parameters estimated from non-fat suppressed in-phase images and Dixon water-only images acquired with TWIST-Dixon in a group of liver patients and found that the discrepancy in T1 and perfusion parameters correlates with the fat fraction. Such result suggests that TWIST-Dixon is a more reliable method for DCE perfusion, especial in fat containing tissues such as liver and pancreas.

16:24 0744.   
Comparison of Contrast-Enhanced Magnetic Resonance Perfusion Imaging and Magnetic Resonance Fourier Decomposition with Single-Photon Emission Computed Tomography as Clinical Reference Standard for Lung Perfusion in Patients with Suspected Chronic Thromboembolic Pulmonary Hypertension
Marcel Gutberlet1, Christian Schönfeld1, Jan Hinrichs2, Julius Renne1, Georg Berding3, Marius Hoeper4, Tobias Welte4, Frank Bengel3, Frank Wacker1, and Jens Vogel-Claussen1
1Institute of Radiology, Medical School Hannover, Hannover, Lower Saxony, Germany, 2Institute of Radiology, Hannover Medical School, Hannover, Lower Saxony, Germany, 3Clinic for Nuclear Medicine, Medical School Hannover, Hannover, Lower Saxony, Germany, 4Clinic of Pneumology, Medical School Hannover, Hannover, Lower Saxony, Germany

Dynamic contrast-enhanced (DCE) MR perfusion imaging and perfusion-weighted (pw) MR Fourier decomposition (FD) are compared to single-photon emission computed tomography (SPECT) ventilation/ perfusion (V/Q) scan as clinical reference standard for lung perfusion in patients with suspected chronic thromboembolic pulmonary hypertension (CTEPH). The lung segments of 13 patients were scored as segmental, subsegmental or no perfusion defect for the evaluated methods. In all patients CTEPH was diagnosed by the three methods. The analysis provided a good agreement of DCE MR perfusion imaging compared to SPECT and a moderate agreement of FD compared to SPECT.

16:36 0745.   Bone Marrow Uptake of Ferumoxytol: A Preliminary Study in Healthy Human Subjects
Pippa Storey1 and Arnaldo A. Arbini2
1Radiology Department, New York University School of Medicine, New York, NY, United States, 2Department of Pathology, New York University School of Medicine, New York, NY, United States

Ultrasmall superparamagnetic iron oxide (USPIO) particles are macrophage-specific contrast agents, which hold promise for identifying bone marrow lesions. This preliminary study in healthy adults investigated marrow uptake of ferumoxytol (Feraheme), a USPIO agent that was recently approved for human use in the United States. Images were acquired before and 3 days after intravenous ferumoxytol administration, using a multiple gradient echo sequence that allowed simultaneous quantification of fat:water ratios and T2*. Results suggest efficient uptake of ferumoxytol by hematopoietic marrow, with less uptake by fatty marrow. Further studies are needed to investigate the utility of this technique in differentiating marrow lesions.

16:48 0746.   Comparative Relaxivities and Efficacies of Gadolinium-Based Commercial Contrast Agents.
Luce Vander Elst1, Jean-Sebastien Raynaud2, Veronique Vives2, Robin Santus2, Gaelle Louin2, Philippe Robert2, Marc Port2, Claire Corot3, and Robert N. Muller1
1Department of General, Organic and Biomedical Chemistry, NMR and Molecular Imaging Laboratory, Mons, Belgium, 2Experimental Imaging, Guerbet, Roissy CdG Cedex, France, 3Experimental Imaging, Guerbet Research, Roissy CdG Cedex, France

In the present study, we have investigated the relaxivities of nonspecific commercial CM by their NMRD profiles and we have compared their respective efficacies in the main clinical application, brain tumors imaging. Analyzed contrast agents are Dotarem®(Gadoterate meglumine), Gadovist®(Gadobutrol), Prohance®(Gadoteridol), Magnevist®(Gadopentetate dimeglumine) and Omniscan®(Gadodiamide). For in vivo application, only the main two products, in terms of published safety and/or relaxivities, were injected; Dotarem® and Gadovist®. In conclusion, no statistical r1 relaxivities and in vivo contrast-to-noise difference was observed.

17:00 0747.   
Risk Factors for Immediate Adverse Events to Gadolinium-Based Contrast Agents (GBCA)
Silvina P. Dutruel1, Zhitong Zou1, and Martin R. Prince1
1Radiology, Weill Cornell Medical College, New York, NY, United States

After reviewing the FDA Adverse Event Reporting System database for immediate reactions due to Gadolinium-based contrast agents (GBCA) we analyzed more than 4500 cases excluding Nephrogenic Systemic Fibrosis (NSF) occurring in the United States from January 2004 to March 2012. The peak age incidence was between 20-60 years. Interestingly, males had nearly twice the death rate of females even though they had fewer reported reactions (p<0.0001). Immediate adverse events showed a marked increase in reporting after the association between NSF and GBCA. Urticaria was the most symptom. Overall, reactions to GBCA are extremely rare but its safety could be enhanced being aware of some demographics parameters.

17:12 0748.   Intra-Individual Assessment of the Bolus Properties of 0.5M Gadopentetate Dimeglumine and 1.0M Gadobutrol in Time-Resolved Contrast-Enhanced 4D-MRA and Dynamic CT in a Minipig Model
Dariusch Reza Hadizadeh1, Gregor Jost2, Hubertus Pietsch2, Martin Weibrecht3, Marco Lierfeld4, Jack Boschewitz1, Hans H. Schild1, and Winfried Albert Willinek1
1Radiology, University of Bonn, Bonn, NRW, Germany, 2MR and CT Contrast Media Research, Bayer Healthcare, Berlin, Berlin, Germany, 3Research Laboratories, Philips Technologie GmbH Innovative Technologies, Aachen, NRW, Germany, 4Institute of Imaging & Computer Vision), RWTH Aachen University, Aachen, NRW, Germany

Time-resolved contrast-enhanced MRA (4D-MRA) is more and more applied in various clinical indications and optimization of the applied contrast agent bolus is crucial. The impact of 1molar concentration on vascular gadolinium concentration (dynamic CT) and signal levels (4D-MRA) was investigated in an animal model of 7 Goettinger minipigs. Transversal slices covered the ascending aorta, descending aorta, and pulmonary trunk. Signal levels, the bolus profile and Gd-concentrations were quantified using 1.0M Gadobutrol (1.0GB) and 0.5M gadopentetate dimeglumine (0.5GD). 4D-MRA offered significantly higher signal and dynamic CT allowed for quantification of respectively higher peak Gd-concentrations using 1.0GB vs. 0.5GD.

17:24 0749.   Anamolous Behavior of Lanthanide Chelates at 7T
Talaignair N. Venkatraman1 and Christopher D. Lascola2
1Radiolgy, Duke University Medical Center, Durham, NC, United States, 2Radiology, Duke University Medical Center, Durham, NC, United States

In this study, we investigated both longitudinal and transverse relaxivities of Magnevist and Ablavar at clinically relevant concentrations in the presence and absence of human serum albumin (HSA) at 7.0T. These data reveal paradoxical behavior of Gadofovest in the presence of protein at higher field strength. The importance of measuring both r1 and r2 relaxivities at high field is also discussed. These data also emphasize the importance of examining both r1 and r2 relaxation properties of various lanthanide contrast agents in tandem, given that changes in these parameters do not necessarily occur in lockstep with each other at different field strengths.

17:36 0750.   Imaging of Dual 19F Tracer Gases for Measurement of Lung Ventilation Properties
Peter E. Thelwall1,2, Christopher R. Fox2, Hannah Walden3, and Andrew Fisher2
1Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, United Kingdom, 2Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom,3Biomedical and Biomolecular Research Centre, Northumbria University, Newcastle upon Tyne, United Kingdom

Inert fluorinated gases can be employed for non-invasive MRI measurement of lung ventilation properties. We demonstrate that the chemical shift difference between two fluorinated gases can be exploited to for spatially separated images of the two components of a gas mixture via 19F MRI. Use of two such tracer gases in a gas wash-in / wash-out experiment allows simultaneous and dynamic regional measurement of lung volume, ventilation dead volume, and ratio of wash-in : wash-out gas.