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

Perfusion & Permeability: Applications
Thursday 25 April 2013
Room 355 EF  13:30 - 15:30 Moderators: David J. Collins, Matthias J. P. van Osch

13:30 0712.   
Whole Brain Arterial Transit Times in the Elderly Estimated Using Arterial Spin Labeling
Henri J.M.M. Mutsaerts1, Edo Richard2, Dennis F.R. Heijtel1, Charles B.L.M. Majoie1, and Aart J. Nederveen1
1Radiology, Academic Medical Center, Amsterdam, Netherlands, 2Neurology, Academic Medical Center, Amsterdam, Netherlands

Transit time measurements may not only improve the quantification of arterial spin labeling but also provide valuable diagnostic information that is unavailable with cerebral blood flow measurements alone. This study estimates micro-vascular arterial transit time by Flow-Encoding Arterial Spin Tagging (FEAST) in a large sample of community-dwelling elderly. The measured transit times show a consistent spatial pattern and depend on age and gender. If no transit time maps are available, our linear regression parameters provide an alternative to a fixed transit time.

13:42 0713.   
Changes in Cerebral Blood Flow and Vasoreactivity to CO2 Measured by Arterial Spin Labeling After 6 Days at 4,350 M
Marjorie Villien1, Pierre Bouzat1, Thomas Rupp2, Paul Robach3, Laurent Lamalle4, Irène Troprès4, François Estève5, Alexandre Krainik6, Patrick Levy2, Jan M. Warnking1, and Samuel Verges2
1Grenoble Institut of Neurosciences, INSERM, Grenoble, France, 2Laboratoire HP2, INSERM, Echirolles, France, 3Ecole Nationale de Ski et d’Alpinisme, Chamonix, France, 4SFR1, Université Joseph Fourier, Grenoble, France, 5ESRF, Grenoble, France, 6Clinique universitaire de neuroradiologie et d'IRM, CHU Grenoble, Grenoble, France

We assess the effects of a sojourn of 6 days at 4,350m on cerebral perfusion and on cerebrovascular reactivity to CO2 using ASL at sea level and transcranial Doppler ultrasound at altitude. We demonstrate that high altitude exposure significantly decreases vasoreactivity to CO2. The increase in CBF observed after several days at high altitude is not only the consequence of the vasodilating effect of hypoxia but probably involves other mechanisms such as changes in cerebral autoregulation and angiogenesis. This study is the first to measure cerebral perfusion and vasoreactivity with ASL after a prolonged stay at high altitude.

13:54 0714.   
Decreased Retinal and Choroidal Blood Flow by MRI Is Correlated with Electroretinography in Retinitis Pigmentosa
Yi Zhang1, Joseph Harrison2, Oscar San Emeterio Nateras1, Steven Chalfin2, and Timothy O. Duong1,2
1Radiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States, 2Ophthalmology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States

Retinitis pigmentosa (RP) is a heterogeneous hereditary disease characterized by photoreceptor degeneration and retinal pigment deposits. Altered ocular blood circulation has been implicated in the degenerative process and/or the pathogenesis of RP. This study demonstrates a novel MRI approach to study the circulatory changes associated with RP in unanesthetized humans. MRI indicates significantly reduced blood flow (BF) in RP retina with a strong link to its suppressed electroretinogram responses.

14:06 0715.   
Multi-Site Evaluations of a TRUST MRI Technique to Measure Brain Oxygenation
Peiying Liu1, Ivan E. Dimitrov1,2, Trevor Andrews2,3, David E. Crane4, Jacinda K. Dariotis5, John Desmond6, Julie Dumas3, Guillaume Gilbert2, Anand Kumar7, Jean-Maxime Leroux8, Bradley MacIntosh4,9, Shaolin Yang7, Guanghua Xiao10, and Hanzhang Lu1
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States, 2Philips Medical Systems, Cleveland, Ohio, United States, 3University of Vermont College of Medicine, Burlington, Vermont, United States, 4Heart and Stroke Foundation Centre for Stroke Recovery, Sunnybrook Research Institute, Toronto, Ontario, Canada,5Department of Population, Family, and Reproductive Health, Johns Hopkins University, Baltimore, Maryland, United States, 6Department of Neurology, Johns Hopkins University, Baltimore, Maryland, United States, 7Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois, United States, 8Department of Radiology, Hospital of the University of Montreal, Montreal, Quebec, Canada, 9Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada, 10Department of Clinical Sciences, University of Texas Southwestern Medical Center, Dallas, Texas, United States

Venous blood oxygenation (Yv) is critical for the quantification of CMRO2, a key biomarker for brain tissue viability and functionality. However, non-invasive quantification of Yv has proved to be challenging. Recently, a T2-Relaxation-Under-Spin-Tagging (TRUST) MRI technique was developed to measure global Yv in the superior sagittal sinus. In this work, we evaluated the applicability and reliability of TRUST in a multi-site setting. We compared Yv values (i.e. accuracy) and standard errors of Yv estimation (i.e. precision) across six imaging centers, and showed that the TRUST sequence can be effectively transferred and performed on a standard 3T scanner at remote sites.

14:18 0716.   Minimizing the Influence of Blood Volume Fraction on Other Pharmacokinetic Parameters in DCE-MRI
Xin Li1, Jeffrey M. Njus1, Seymur Gahramanov2, Csanad G. Várallyay2, John W. Grinstead3, Charles S. Springer, Jr.1, Edward A. Neuwelt2, and William D. Rooney1
1Advanced Imaging Research Center, Oregon Health & Science University, Portland, Oregon, United States, 2Department of Neurology, Oregon Health & Science University, Portland, Oregon, United States, 3Siemens Healthcare, Portland, Oregon, United States

For DCE-MRI, it is possible to obtain consistent Ktrans (CR transfer constant) and ve (extracellular, extravascular volume fraction) values whether incorporating vb (blood volume fraction) or not into DCE-MRI modeling. This often requires minimizing the influence of vb in DCE-MRI data time-courses.

14:30 0717.   Prediction of Response to Chemotherapy in Patients with Osteosarcoma and Ewing’s Sarcoma
Louisa Bokacheva1, Ya Wang1, Wei Huang2, David M. Panicek3, and Jason A. Koutcher1,3
1Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, United States, 2Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States, 3Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, United States

DCE MRI was performed in 34 patients with osteosarcoma and Ewing's sarcoma before, during and after neoadjuvant chemotherapy. Patients underwent surgery with histological assessment of necrosis or radiation therapy and were followed up clinically for up to six years. Voxel parameters were derived from DCE MRI data using linearized form of the Tofts model and population-based arterial input function. The mean tumor Ktrans decreased significantly at the time of the third MRI session relative to baseline. Both the mean Ktrans value and percent decrease relative to baseline were predictive of histological response, but did not appear to predict survival.

14:42 0718.   Differentiation of Myeloma and Metastatic Cancer in the Spine Using Dynamic Contrast Enhanced MRI
Ning Lang1, Min-Ying Su2, Hon J. Yu2, Muqing Lin2, and Huishu Yuan1
1Department of Radiology, Peking University Third Hospital, Beijing, China, 2Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California, Irvine, CA, United States

DCE-MRI was performed to differentiate between myelomas and metastatic cancers in the spine. The peak signal enhancement percentage (SE%), the steepest wash-in SE%, and the wash-out SE%, were calculated. The two-compartmental pharmacokinetic model was used to obtain Ktrans and kep. The myeloma group had a higher peak SE%, a higher wash-in and wash-out SE%, and also a higher Ktrans and kep. The ROC show that the AUC was 0.798 for Ktrans, 0.864 for kep, and 0.919 for combined Ktrans and kep. The results show that DCE-MRI may provide additional information for making differential diagnosis of spinal tumors.

14:54 0719.   
Initial Clinical Application of Simultaneous MR Angiography and Perfusion (MRAP) in Peripheral Arterial Disease
Katherine L. Wright1, Arash Aghel2, Nicole Seiberlich1, Mark A. Griswold1,3, Anne Hamik2, and Vikas Gulani1,4
1Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States, 2Case Cardiovascular Research Institute, Case Western Reserve Univ. and University Hospitals, Cleveland, Ohio, United States, 3Radiology, University Hospitals Case Medical Center, Cleveland, Ohio, United States, 4Radiology, Case Western Reserve University, Cleveland, Ohio, United States

Complete evaluation of both large and small vessels would typically require two separate contrast enhanced acquisitions: MR angiography and dynamic contrast enhanced (DCE) MRI. MRAP (MR Angiography and Perfusion) is a technique that allows for simultaneous acquisition of both these exams by using an optimized, 3D, time-resolved contrast-enhanced acquisition with high spatial/temporal resolution. This preliminary study applies MRAP to the clinical evaluation of peripheral arterial disease (PAD). DCE-MRI perfusion measurements from various muscles in the leg were correlated to ankle brachial index (ABI) data to evaluate the use of MRAP in PAD.

15:06 0720.   Preliminary Analysis of Arterial Input Function Derived from Dynamic Contrast Enhanced MRI in Children with Cancer
Keiko Miyazaki1, Matthew R. Orton1, David John Collins1, James A. d'Arcy1, Toni Wallace2, Lucas Moreno3, Andrew Pearson3, Stergios Zacharoulis3, Martin O. Leach1, and Dow-Mu Koh2
1CR-UK and EPSRC Cancer Imaging Centre, The Institute of Cancer Research, Sutton, Surrey, United Kingdom, 2Department of Diagnostic Radiology, The Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom, 3Department of Paediatric Oncology, The Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom

The aim of this study is to investigate the feasibility and challenges of obtaining arterial input functions from paediatric DCE-MRI studies. Preliminary analysis of AIFs obtained from paediatric DCE-MRI data have shown it is possible to obtain consistent AIFs using a power injector. Inconsistencies in hand-injected AIFs found in this study have highlighted the need to optimize modes of contrast agent delivery through central lines. This is an ongoing study whereby further data will continue to be acquired in order to build a more representative paediatric population AIF that would enable quantitative DCE-MRI data analyses in paediatric clinical trial settings.

15:18 0721.   Dynamic Contrast-Enhanced Magnetic Resonance Imaging Enables Personalized Anti-EMMPRIN Therapy for Pancreatic Cancer
Hyunki Kim1, Christopher Rigell1, Guihua Zhai1, Kyle Lee1, Sharon Samuel1, Amber Martin1, Timothy Beasley1, Long Shan Li2, David Boothman2, and Kurt Zinn1
1University of Alabama at Birmingham, Birmingham, AL, United States, 2Radiation Oncology, UT Southwestern Medical Center, Dallas, TX, United States

Anti-EMMPRIN monotherapy has demonstrated strong anti-tumor effect via preventing tumor-cell invasion and neovascularization. However, care must be taken when applying anti-EMMPRIN antibody in combination with another small-molecule chemotherapeutic agent like gemcitabine, because the antiangiogenic effect of anti-EMMPRIN antibody may excessively decrease the tumor vasculature for hypovascular tumors, reducing the tumor delivery of the chemotherapeutic agent while increasing tumor hypoxia. In this study, differential therapeutic efficacy of anti-EMMPRIN antibody combined with non-targeting small-molecule chemotherapy drugs was confirmed according to tumor vascularity, and a clinical protocol to enable personalized treatment of pancreatic cancer patients based on DCE-MRI was suggested.