ISMRM 23rd Annual Meeting & Exhibition • 30 May - 05 June 2015 • Toronto, Ontario, Canada

Scientific Session • Perfusion & Permeability: Validation Studies

Thursday 4 June 2015

Room 714 A/B

10:30 - 12:30


Weiying Dai, Ph.D., Ronnie Wirestam, Ph.D.

10:30 0789.   Dynamic contrast-enhanced MR imaging in rectal cancer: study of inter-software accuracy and reproducibility using simulated and clinical data
Luc Beuzit1, Pierre-Antoine Eliat2, Elise Bannier1,3, Jean-Christophe Ferré1,3, Yves Gandon1, Vanessa Brun1, and Hervé Saint-Jalmes4,5
1Radiology, CHU Rennes, Rennes, France, 2PRISM-Biosit CNRS UMS 3480, INSERM UMS 018, University of Rennes I, Rennes, France, 3Neurinfo MR imaging platform, University of Rennes I, Rennes, France, 4Radiology, Eugène Marquis Cancer Institute, Rennes, France, 5LTSI, UMR 1099, INSERM, University of Rennes I, Rennes, France
Dynamic contrast-enhanced MRI is a promising biomarker for investigating early tumor response, but is subject to numerous factors of variation. The purpose of this study was to assess the potential role of software packages in this variability. Using an original DICOM file processing method, we studied the accuracy of software packages for measuring pharmacokinetic parameters on simulated data. We showed significant errors for all five software packages studied, leading to poor inter-software agreement. A very poor agreement was observed among the software packages when processing clinical data consisting of dynamic contrast-enhanced MR images of rectal tumors.

10:42 0790.   Validation of Quantitative Blood Flow with 3D Gradient Echo (GRE) Dynamic Contrast-enhanced Magnetic Resonance Imaging (DCE-MRI) using Blood Pool Contrast Medium in Skeletal Muscle of Swine
Stefan Hindel1, Anika Sauerbrey1, Marc Maaß2, and Lutz Lüdemann1
1Strahlenklinik und Poliklinik, Universitätsklinikum Essen, Essen, North Rhine-Westphalia, Germany, 2Evangelisches Krankenhaus Wesel GmbH, North Rhine-Westphalia, Germany

We validated the feasibility of absolute regional perfusion quantification by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with k-space shared sampling and a blood pool contrast agent in combination with a two-compartment tracer kinetic model in low-perfusion tissue. Seven female pigs were investigated. An ultrasonic Doppler probe was attached to the right femoral artery to determine the total flow in the hind leg musculature. The overall flow of the hind leg muscles, as measured by the ultrasound probe, highly correlated with the total flow from the MRI measurement, r = 0.89 and P=10^(-7).

10:54 0791.   Effects of temporal resolution on DCE-MRI parameter estimation: In-vivo repeatability analysis of lung tumors using retroactively adjustable KWIC reconstruction
Xia Zhao1,2, Yiqun Xue1,2, Mark Rosen2, Hyunseon Kang3, Ramesh Rengan4, and Heekwon Song1,2
1Laboratory for Structural NMR Imaging, University of Pennsylvania, Philadelphia, PA, United States, 2Department of Radiology, Hospital of University of Pennsylvania, Philadelphia, PA, United States, 3MD Anderson Cancer Center, University of Texas, Houston, TX, United States, 4Department of Radiation Oncology, University of Washington School of Medicine, Seattle, WA, United States

In this work, we investigate the effects of temporal resolution on measured tumor perfusion parameters and also its effects on repeatability on a test-retest dataset acquired in vivo in patients with lung tumor. We utilize interleaved radial acquisition (golden angle view angle increment) along with KWIC reconstruction which enables different temporal resolutions to be chosen retrospectively during image reconstruction. Our results demonstrate that repeatability is relatively constant up to about 13 sec frame rate (CV ~ 11%). In agreement with previous simulation studies, Ktrans is increasingly underestimated at reduced temporal resolutions.

11:06 0792.   Measuring blood-brain-barrier permeability using Diffusion-Weighted Arterial Spin Labeling (DW-ASL): Corroboration with Ktrans and Evan’s blue measurements
Yash Vardhan Tiwari1,2, Qiang Shen1, Zhao Jiang1, Wei Li1, Justin Long1,2, Chenling Fang1,2, and Timothy Duong1
1Research Imaging Institute, UT Health Science Center, San Antonio, Texas, United States, 2Biomedical Engineering, UT, San Antonio, Texas, United States

Blood-brain-barrier (BBB) dysfunction has been implicated in a number of neurological disorders, such as multiple sclerosis, stroke and cancer. BBB integrity can be assessed by measuring the water exchange rate across the BBB (Kw) – defined as PS/Vc where PS is permeability surface area product and Vc is capillary distribution volume of water. Diffusion-weighted arterial spin labeling (DW-ASL) was recently proposed to measure Kw without using an exogenous contrast agent in humans1. However, this approach has not been validated. The goal of this study was to compare Kw measurements (DW-ASL) with Ktrans (DCE MRI) and histological staining (Evan’s blue) in the same rats. Measurements were also made before and after mannitol administration to break the BBB.

11:18 0793.   Intra and Inter-subject Reproducibility of Arterial Transit Time
Tracy Ssali1,2, Udunna C Anazodo1,2, Mahsa Shokouhi1, Bradley J MacIntosh3, and Keith St Lawrence1,2
1Laswon Health Research Institute, London, Ontario, Canada, 2University of Western Ontario, London, Ontario, Canada, 3Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada

It is known that knowledge of the arterial transit time (ATT) is essential for CBF quantification; however, typically ATT imaging is time consuming. The aim of this study was to assess intra- and inter-subject reproducibility of ATT. Across sessions and subjects, the voxel-wise GM CV were 6.0% and 10.0%, respectively. Variance in mean GM ATT inter-subject was 44.7ms (CV=5.4%) and 5.9ms (CV=0.7%) inter-session. The low variance demonstrates the stability of ATT measurements in young healthy individuals. Next, would be to assess reproducibility of ATT in older subject groups and patient populations with cerebral pathology where perfusion characteristics have greater variability.

11:30 0794.   Comparison of ASL inversion efficiency and CBF quantification for 3 perfusion techniques at 3 magnetic fields
Clement Stephan Debacker1,2, Jan M Warnking1,3, Sacha Koehler2, Jerome Voiron2, and Emmanuel L Barbier1,3
1GIN, Univ. Grenoble Alpes, Grenoble, France, 2Bruker BioSpin MRI, Ettlingen, Germany, 3U836, INSERM, Grenoble, France

The purpose of this study is to evaluate the reproducibility across magnetic field of cerebral blood flow (CBF) quantification using Arterial Spin Labeling (ASL) methods. Three ASL methods (pulsed ASL (PASL), continuous ASL (CASL), and pseudo-continuous ASL (pCASL)) were evaluated at 4.7, 7, and 11.7T in 43 rats. Among the three techniques evaluated, pCASL appears as the most reproducible method across magnetic fields.

11:42 0795.   
Assessing relationship between intracranial vascular compliance and aortic pulse wave velocity using MRI
Lirong Yan1, Collin Liu2, Robert Smith1, Mayank Jog1, Kate Krasileva1, Cheng Li3, Michael Langham3, and Danny JJ Wang1
1Neurology, University of California Los Angeles, Los Angeles, CA, United States, 2University of Southern California, CA, United States, 3University of Pennsylvania, Philadelphia, PA, United States

The purpose of this study was to investigate the relationship between intracranial vascular compliance and aortic pulse wave velocity (PWV) in a cohort of subjects with mixed vascular risks. We found there was significant negative correlation between intracranial VC and aortic PWV. Subjects with high vascular risks showed reduced intracranial VC and elevated aortic PWV compared to subjects with low vascular risks. These findings suggest that changes in vascular compliance typically extend from aorta to intracranial vessels.

11:54 0796.   
Validation of dual-injection dynamic susceptibility contrast perfusion weighted imaging against pseudo-continuous arterial spin labeling: a pilot study
Natalie M Wiseman1, Meng Li2, Mahmoud Zeydabadinezhad3, Jessy Mouannes-Srour3, Yongquan Ye2, E. Mark Haacke2,3, and Zhifeng Kou2,3
1Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI, United States, 2Department of Radiology, Wayne State University School of Medicine, Detroit, MI, United States, 3Department of Biomedical Engineering, Wayne State University, Detroit, MI, United States

DSC-PWI suffers from blooming, clipping, and saturation effects in large vessels, which make arterial input function (AIF) determination unreliable. To combat this, we used a dual-injection method in which 1/6 of the contrast dose is used to determine the AIF and the remaining 5/6 is used to visualize perfusion in brain tissue. We compared these CBF measurements to pseudo-continuous ASL (pCASL) CBF measurements. The correlation coefficients of 0.85 and 0.63 show good correlation in large ROIs and slightly less good correlation in the small ROIs, respectively. In conclusion, the dual-injection DSC-PWI method provides a reliable, high resolution measurement of CBF.

12:06 0797.   An extensible methodology for creating realistic anthropomorphic digital phantoms for quantitative imaging algorithm comparisons and validation
Ryan J Bosca1 and Edward F Jackson1
1Medical Physics, University of Wisconsin - Madison, Madison, WI, United States

Increasing interest in and use of quantitative imaging biomarkers in clinical research and clinical practice necessitates careful assessment and mitigation of bias and variance associated with the acquisition and image analysis techniques, especially in the context of spatially heterogeneous processes. In this work, we report an extensible methodology for creating an anthropomorphic digital reference object (DRO) with a synthetic tumor to evaluate quantitative imaging algorithms using a realistic data analysis scenario with known “ground truth”. Such a realistic DRO facilitates quantitative imaging biomarker algorithm comparisons and validation.

12:18 0798.   A Simple and Cheap Perfusion Phantom
Ina Nora Kompan1,2, Klaus Eickel3,4, Federico von Samson-Himmelstjerna1,5, Benjamin Richard Knowles6, and Matthias Guenther1,2
1Fraunhofer MEVIS, Bremen, Bremen, Germany, 2mediri GmbH, Heidelberg, Baden-Württemberg, Germany, 3Fraunhofer MEVIS, Bremen, Germany,4Universitätsklinikum Essen, Essen, Nordrhein-Westfalen, Germany, 5Charité, Berlin, Germany, 6Universitätsklinikum Freiburg, Freiburg, Baden-Württemberg, Germany

For optimization and validation of new dynamic contrast-enhanced MRI sequences, a simple and cheap perfusion phantom is developed. Contrast agent is injected via a hose into a sponge and is washed out by a constant water flow. The phantom can be quantitatively described using a gamma-variate function, providing heterogeneous parameter maps. The phantom experiment is relatively well reproducible.