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

Scientific Session • CESToronto

Thursday 4 June 2015

Room 701 B

10:30 - 12:30


Seth A. Smith, Ph.D., T.B.A.

10:30 0779.   
Highly-accelerated chemical exchange saturation transfer (CEST) measurements with linear algebraic modeling (SLAM)
Yi Zhang1, Hye-Young Heo1, Dong-Hoon Lee1, Shanshan Jiang1, Paul Bottomley1, and Jinyuan Zhou1,2
1Division of MR Research, Department of Radiolgoy, Johns Hopkins University, Baltimore, Maryland, United States, 2F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, United States

Voxel-by-voxel CEST maps provide in vivo molecular level information that can have clinical value. However, for quantitative measures, regional average CEST measurements routinely suffice for diagnosis and or assessing treatment. A recently-developed method—spectroscopy with linear algebraic modeling or SLAM—can directly provide compartmental measurements, while offering a dramatic reduction in scan times by dropping low-SNR, high k-space phase-encoding steps depending on the number of compartments. Here, SLAM is adapted to CEST acquisitions from brain tumor studies, and shown to yield quantitatively equivalent results to standard CEST, with acceleration factors of up to 45-fold.

10:42 0780.   
CEST analysis via MR fingerprinting
Nicolas Geades1, Penny Gowland1, and Olivier Mougin1
1Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom

The study presents a new method for fitting z-spectra to physically meaningful models in a reasonable computational time, by using a look up table based on Bloch Mc-Connell simulations to estimate the relative amplitudes of the different proton pools whilst correcting for the effects of inhomogeneities and other tissues properties.

10:54 0781.   Monitoring therapeutic response on non-small cell lung cancer in chemotherapy by amide proton transfer (APT) imaging in mice
Keisuke Ishimatsu1, Shanrong Zhang1, Koji Sagiyama1, Osamu Togao1, Brenda Timmons2, John Minna2, and Masaya Takahashi1
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States, 2Hamon Center for Therapeutic Oncology, Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States

The objective of our study is to investigate whether amide proton transfer (APT) imaging can be used for monitoring treatment responses of the lung cancer in chemotherapy. We compared temporal changes of APT signal in a non-small cell lung carcinoma with and without erlotinib which is a small molecule epidermal growth factor receptor tyrosine kinase inhibitor in mice.

11:06 0782.   
Dynamic Imaging of D-Glucose at 7T: First Experiments in Human Brain
Xiang Xu1,2, Craig K. Jones1,2, Nirbhay N. Yadav1,2, Linda Knutsson3, Jun Hua1,2, Rita Kalyani4, Erica Hall4, John Laterra5, Jaishri Blakeley5, Roy Strowd5, Prakash Ambady5, Martin Pomper1, Peter Barker1,2, Guanshu Liu1,2, Kannie W.Y. Chan1,2, Michael T. McMahon1,2, Robert D. Stevens5,6, and Peter van Zijl1,2
1Department of Radiology, Johns Hopkins University, Baltimore, MD, United States, 2F. M. Kirby Research Center, Kennedy Krieger Institute, Baltimore, MD, United States, 3Department of Medical Radiation Physics, Lund University, Lund, Sweden, 4Division of Endocrinology, Diabetes, & Metabolism, Johns Hopkins University, Baltimore, MD, United States, 5Department of Neurology, Johns Hopkins University, Baltimore, MD, United States, 6Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, United States

Recent animal studies show that D-glucose is a potential biodegradable MRI contrast agent. Here, using chemical exchange saturation transfer (CEST) MRI, we show that it is possible to detect dynamic changes in the human brain at 7T during and after infusion of D-glucose. The dynamic glucose images provide information regarding blood arterial input function (AIF), tissue perfusion and glucose transport. We present data from both healthy volunteers and a brain tumor patient with anaplastic astrocytoma showing glucose enhancement in the tumor region. This method is promising for studying perfusion properties of tumors and the brain.

11:18 0783.   Chemical exchange sensitive Spin-lock MRI of deoxyglucose transport and metabolism in brain
Tao Jin1, Hunter Mehrens1, and Seong-Gi Kim1,2
1Department of Radiology, University of Pittsburgh, Pittsburgh, PA - Pennsylvania, United States, 2Center for Neuroscience Imaging Research, Institute for Basic Science, SKKU, Suwon, Korea

Recent studies showed an increase of chemical exchange-sensitive spin-lock (CESL) MRI signal during administration of 2-deoxy-glucose (2DG). Since this CESL technique lacks molecular specificity, more studies are necessary to examine whether the signal change is caused by the transport and/or the metabolism of 2DG. The results of our in vivo study show that the CESL signal induced by administration of 2DG is strongly dependent on the injecting dose, anethesia level and brain regions. It likely contains both transport and metabolisim components and can be used as biomarker for the studied of both processes.

11:30 0784.   Chemical Exchange Saturation Transfer (CEST) Imaging with Double Angles and Varying Duty Cycles
Ke Li1,2, Hua Li1,3, Zhongliang Zu1,2, Junzhong Xu1,2, Jingping Xie1,2, Bruce M Damon1,2, Mark D Does1,2, John C Gore1,2, and Daniel F Gochberg1,2
1Institute of Imaging Sciences, Vanderbilt University, Nashville, TN, United States, 2Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, 3Department of Physics and Astronomy, Vanderbilt University, Nashville, TN, United States

The conventional chemical exchange saturation transfer (CEST) imaging is always confounded by the MT asymmetry of the macromolecular proton pool and nuclear overhauser enhancement. This work describes the development of a new metric, named magnetization transfer ratio with double angle and varying duty cycles (MTRdouble,vdc), based on pulsed-CEST. A π pulse train at high duty cycle (dc) (83.8% in this work) is used to maximize exchange effects; while a 2π pulse train at low dc (20.95% in this work) is used to minimize such effects. The equivalency of this approach to an ideal continuous-wave (CW) experiment is also demonstrated.

11:42 0785.   
Balanced Steady State Free Precession (bSSFP) from an effective field perspective: application to the detection of exchange (bSSFPX)
Shu Zhang1, Zheng Liu2, Robert E. Lenkinski1,3, and Elena Vinogradov1,3
1Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 2Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States, 3Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States

In this work we demonstrate that pulses of bSSFP generate an effective RF field akin to the saturation/spin-lock RF train. Thus, bSSFP and CEST/T1rho experiments are completely analogous. While in CEST the Z component of magnetization is observed, here we are focusing on the XY component. Analysis of the off-resonance frequency dependence of bSSFP profile (bSSFPX) provides information similar to CEST. We present a theoretical treatment, confirmation by simulation, and demonstrate the proof-of-principle with an image of an exchanging agent acquired using this bSSFPX approach. This method may lead to fast acquisition and quantification approaches.

11:54 0786.   Optimizing multislice acidoCEST MRI for assessments of extracellular pH in tumor and kidney tissues.
Edward A Randtke1, Kyle Jones1, Christy Howison1, Julio Cárdenas-Rodríguez1, and Mark D Pagel1
1Biological and Medical Imaging, University of Arizona, Tucson, Arizona, United States

We have incorporated the Phase-Offset MultiPlanar (POMP) Simultaneous MultiSlice (SMS) technique into CEST-FISP MRI to create multislice acidoCEST MRI protocol that can measure extracellular pH in 3D volumes of tumor and kidney tissues. Gaussian filtering was critical for improving CEST MRI for voixelwise analysis. The pHe values in tumor and kidney tissues were measured using Bloch-McConnell fitting of CEST spectra. Although voxelwise pHe measurements have some variance, pHe analyses of tissue and sub-tissue regions have excellent precision.

12:06 0787.   Cardiac CEST MRI of paraCEST labeled Cells in Cell Therapy
Ashley Pumphrey1, Scott Thalman2, Zhengshi Yang1, Shaojing Ye1, and Moriel Vandsburger1,3
1Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, United States, 2Department of Biomedical Engineering, University of Kentucky, Lexington, KY, United States, 3Department of Physiology, University of Kentucky, Lexington, KY, United States

Using a novel cardiac chemical exchange saturation transfer (CEST) method, paraCEST labeled cells following myocardial transplantation are imaged in the mouse heart for the first time. Utilizing our recently developed cardioCEST pulse sequence we demonstrate in vivo imaging of Eu-HPDO3A labeled cells in which the contrast can essentially be "turned on" at the resonant frequency of the contrast agents exchangeable proton. With the possibility of multiple CEST contrast agents being used simultaneously, cardioCEST allows for multiplex imaging of cell tracking alongside important functional parameters of cardiac function without causing disruptive signal voids.

12:18 0788.   Salicilyc-acid CEST PAMAM polymers for CEST imaging of delivery to brain tumors
Nikita Oskolkov1,2, Kannie W.Y. Chan1,2, Xiaolei Song1,2, Tao Yu3, Peter C.M. van Zijl1,2, Justin Hanes3, Rangaramanujam M. Kannan3, and Michael T. McMahon1,2
1The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins School of Medicine, Baltimore, Maryland, United States, 2F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, United States, 3Center for Nanomedicine, Johns Hopkins School of Medicine, Baltimore, Maryland, United States

The Poly(amido amine) (PAMAM) dendritics form a class of three dimensional, macromolecular hyperbranched globular polymers also known as dendrimers. Dendrimers have been shown to be an efficient drug delivery platform as a result of their physical and chemical properties. Their controlled size and the ease of conjugation with targeting ligands, drugs and imaging agents (i.e. MRI, X-ray, PET) for production of multifunctional nanoparticles allows the use of dendrimers as theranostic agents. In this study we have prepared a dendrimer particle with increased MRI visibility, distinguishing from contrast of dendrimer core3, which allows non-invasive visual guidance of drug delivery into brain tumors through covalent conjugation of a salicylic acid (SA) analogue which displays specific high-frequency-offset CEST contrast4 to a 4th generation carboxylate-terminated dendrimer (G3.5) and evaluated brain tumor uptake in vivo.