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

Power Pitch Session
The Cardiovascular Power Hour
Power Pitch Theatre, Exhibition Hall, 16:30 - 17:30
Plasma Screens, Exhibition Hall, 17:30 - 18:30
Moderators: Daniel B. Ennis, Ph.D., Reza Nezafat, Ph.D.
Monday 1 June 2015

Click this video icon to view the introductory session:

Note: The videos below are only the slides from each presentation. They do not have audio.

Plasma # Program #  
1 0174. Gradient-Induced Voltages on 12-lead ECGs during High-Duty-Cycle MRI Sequences and a Theoretically based Method to Remove Them
HuaLei Zhang1, Zion Tsz ho Tse2, Charles L. Dumoulin3, Ronald Watkins4, Wei Wang1, Jay Ward5, Raymond Kwong1, William Stevenson1, and Ehud J. Schmidt1
1Brigham and Women's Hospital, Boston, MA, United States, 2University of Georgia, Georgia, United States, 3Cincinnati Children’s Hospital Medical Center, Cincinnati, United States, 4Stanford University, CA, United States, 5E-TROLZ, Inc, Andover, MA, United States

To restore high fidelity 12-lead ECG traces acquired during high-duty-cycle MR imaging sequences, we developed techniques to restore ECGs distorted by gradient-induced voltages. We developed a system response function which characterized induced voltages at each channel based on simultaneously recorded gradient waveforms. We then measured gradient-induced voltages in volunteers at spectrum and amplitude up to 24 KHz and +/-10Volt, and demonstrated close agreement between the theoretical and measured gradient-induced voltages. A rapid training sequence permitted computing the response function coefficients, followed by real-time gradient-induced voltage removal during imaging. The response function coefficients varied by subject, sequences parameters, and slice orientation.

2 0175.
Automatic detection of inflammatory ‘hotspots’ in abdominal aortic aneurysms to identify patients at risk of aneurysm expansion and rupture
Yolanda Georgia Koutraki1,2, Chengjia Wang1,3, Jennifer Robson2, Olivia Mcbride2, Rachael O. Forsythe2, Tom J. MacGillivray1, Calum D. Gray1, Keith Goatman3, J. Camilleri-Brennan2, David E. Newby1,2, and Scott I. Semple1,2
1Clinical Research Imaging Centre, University of Edinburgh, Edinburgh, United Kingdom, 2Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom, 3Toshiba Medical Visualization System - Europe, Edinburgh, United Kingdom

The measurement of the diameter of abdominal aortic aneurysms (AAA) as a criterion for repair has been proved to be imperfect, thus new methods are required. Recently Ultrasmall Superparamagnetic Particles of Iron Oxide (USPIO) in AAA were shown to identify cellular inflammation in MRI scans and patients were classified in 3 groups based on the inflammation patterns. Group 3, with ‘inflammatory hotspots’ on the aortic wall, was found to have a 3fold expansion of AAA. The classification process was manual and thus time-consuming and prone to inter- and intra-observer variability. We are suggesting the use of our automated classification software which has excellent agreement rates in ‘hotspot’ detection, while it provides a 40 times faster, robust and objective processing, with the potential of sub-classification of the crucial patient group.

3 0176. In-vivo lipid quantification in carotid plaques using multi-slice T2 mapping: histological validation
Luca Biasiolli1,2, Joshua T Chai1, Linqing Li3, Ashok Handa4, Peter Jezzard3, Robin P Choudhury1, and Matthew D Robson2
1AVIC, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom, 2OCMR, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom, 3FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, 4Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom

Quantitative T2 mapping has recently emerged as a promising alternative to multicontrast MRI for carotid plaque characterization, as it can measure plaque MR properties directly on a voxel by voxel basis and discriminate between the lipid core and the surrounding fibrous tissue. In this study we have developed and validated a DANTE-MESE sequence for multi-slice T2 mapping and used it for in-vivo plaque lipid quantification. We have demonstrated that our method is strongly correlated with histology and can discriminate between symptomatic and asymptomatic plaques, and hence has a lot of potential for clinical application.

4 0177. Coronary Endothelial Function Assessment Using Self-Gated Cardiac Cine MRI with golden angle acquisition and k-t Sparse SENSE
Jerome Yerly1,2, Giulia Ginami1,2, Giovanna Nordio1,2, and Matthias Stuber1,2
1Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 2Center for Biomedical Imaging (CIBM), Lausanne, Switzerland

Coronary endothelial function (CEF) can be assessed non-invasively by measuring the vasodilatation of the coronary arteries in response to isometric handgrip exercise using bright blood cine MRI. However, cine MRI requires an external ECG signal to synchronize the data acquisition, which can be challenging to obtain in patients at high field strength. To address this hurdle, we propose a cardiac self-gated technique that combines golden angle radial acquisition with k-t sparse SENSE to reconstruct cardiac cine images without ECG. We demonstrate that our framework can accurately assess CEF and provide results equivalent to those of the standard ECG-gated technique.

5 0178.
Inter-study repeatability of self-gated quantitative myocardial perfusion MRI
Devavrat Likhite1, Promporn Suksaranjit2, Chris McGann2, Brent Wilson2, Imran Haider2, Ganesh Adluru1, and Edward DiBella1
1UCAIR, University of Utah, Salt Lake City, Utah, United States, 2Division of Cardiovascular Medicine, Department of Medicine, University of Utah, Salt Lake City, Utah, United States

Dynamic contrast enhanced MRI is maturing as a tool in contemporary cardiovascular medicine and quantifying cardiac perfusion is becoming clinically relevant. The purpose of this study is to understand the inter-study repeatability of a self-gated approach for quantification of myocardial perfusion. Nine subjects underwent self-gated regadenoson rest/stress imaging twice within 9.5±4.5 days. The systolic images showed good repeatability of the myocardial perfusion reserve, with a coefficient of variation similar to published gated studies.

6 0179. Initial Experience in Patients for Highly Accelerated Free-Breathing Whole-Heart Coronary MRA - permission withheld
Christoph Forman1, Christoph Tillmanns2, Michael O. Zenge1, and Michaela Schmidt1
1Siemens AG, Healthcare, Imaging and Therapy Systems, Magnetic Resonance, Erlangen, Germany, 2Diagnostikum Berlin, Berlin, Germany

3D whole-heart magnetic resonance angiography (CMRA) with high isotropic resolution allows the assessment of the complete cardiac anatomy including the coronary arteries. The highly accelerated data acquisition with sparse, incoherent sampling enables its integration into routine clinical examination even with navigator-gating. In this work, the resulting image quality and diagnostic performance of sparse CMRA was evaluated in patients and compared to computed tomography angiography (CTA). Although CMRA was inferior to CTA, it provides a promising radiation-free method visualizing congenital malformations and has great potential for screening, e.g. to assess the risk of sudden cardiac death.

7 0180. Accelerated Four-dimensional, multiphase, steady-state imaging with Contrast Enhancement (MUSIC) using Parallel Imaging and Compressed Sensing
Ziwu Zhou1, Fei Han1, Stanislas Rapacchi1, Ihab Ayad2, Isidro Salusky3, Adam Plotnik1, Paul Finn1, and Peng Hu1
1Radiology, UCLA, Los Angeles, CA, United States, 2Anesthesiology, UCLA, Los Angeles, CA, United States, 3Pediatrics, UCLA, Los Angeles, CA, United States

In this study, we evaluate the usage of Parallel Imaging and Compressed Sensing to accelerate a recently proposed four dimensional, non-breath-hold, multiphase steady-state imaging technique (MUSIC), in hope to decrease acquisition time and increase temporal resolution. Based on initial experience on nine pediatric patients with congenital heart disease, accelerated MUSIC has similar image quality with half acquisition time, compared with original MUSIC. Image reconstruction is implemented in C/C++ that allows clinically acceptable reconstruction time, make it feasible for practical usage.

8 0181.
Dual Agent Relaxivity Cancellation (DARC) Imaging, a Novel Imaging Method for Dark Blood Post-Contrast Imaging: Application to MR Lymphangiography
Jeffrey H Maki1, Noah Briller1, Peter C Neligan2, and Gregory J Wilson1
1Radiology, University of Washington, Seattle, WA, United States, 2Plastic Surgery, University of Washington, Seattle, WA, United States

A novel MR imaging method using two contrast agents (one for enhancement of non-blood-pool tissues, and one for suppression of blood-pool signal), named Dual Agent Relaxivity Cancellation (DARC), was developed for the visualization of lymphatic channels. The MR lymphangiography technique utilizes the T1 signal enhancement of intracutaneously injected gadobenate and the blood-pool T2* signal suppression of intravenously injected ferumoxytol. When imaged with mDixon using relatively long TE’s (4-8ms), lymphatic channels are easily visualized without venous overlay.

9 0182. CMR-footprinting: Quantifying tissue parameters with clinical pulse sequence simulations improves measurement accuracy - an example with MOLLI T1 mapping
Christos G. Xanthis1,2, Sebastian L. Bidhult1, Georgios Kantasis1,2, Mikael Kanski1, Einar Heiberg1,3, Håkan Arheden1, and Anthony H. Aletras1,2
1Cardiac MR group Lund, Dept. of Clinical Physiology, Lund University, Lund, Skåne, Sweden, 2Department of Computer Science and Biomedical Informatics, University of Thessaly, Lamia, Lamia, Greece, 3Department of Biomedical Engineering, Faculty of Engineering, Lund University, Lund, Skåne, Sweden

MR simulations have been used in a limited scope in the past. In this study, we propose CMR-footprinting, a new method showing how quantitative CMR with clinical pulse sequences can be improved by comparing the signals acquired from the MRI scanner to the entire pool of possible outcomes that are produced by massively parallel MRI simulations of the identical pulse sequence for different tissue types. A MOLLI example was used and CMR-footprinting demonstrated overall T1 accuracy improvement and good performance even for long T1s with a zero seconds pause.

10 0183.
Modified Wideband 3D Late Gadolinium Enhancement (LGE) MRI for Patients with Implantable Cardiac Devices
Shams Rashid1, Stanislas Rapacchi1, Kalyanam Shivkumar1,2, Adam Plotnik1, J. Paul Finn1,3, and Peng Hu1,3
1Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States, 2UCLA Cardiac Arrhythmia Center, University of California, Los Angeles, Los Angeles, CA, United States, 3Biomedical Physics Inter-Departmental Graduate Program, University of California, Los Angeles, Los Angeles, CA, United States

We have modified a 3D LGE sequence for LGE cardiac MRI of patients with implanted cardiac devices by implementing a wideband inversion pulse and increasing the RF excitation pulse bandwidth. We show reduced hyper-intensity artifacts due to the wideband inversion pulse. We also show that the conventional 3D LGE sequence produces artifacts due to slab profile distortion, which are reduced by increasing the bandwidth of the RF excitation pulse. We present results from phantom, volunteer and patient studies.

11 0184.
Black Blood Late Gadolinium Enhancement (BB-LGE) using a joint T2 Magnetization Preparation and Inversion Preparation
Tamer Basha1, Sébastien Roujol1, Kraig V. Kissinger1, Beth Goddu1, Warren J. Manning1,2, and Reza Nezafat1
1Department of Medicine, Beth Israel Deaconess Medical Center & Harvard Medical School, Boston, Massachusetts, United States, 2Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States

Late gadolinium enhancement (LGE) allows depiction of scar/fibrosis in patients with cardiovascular disease. An inversion recovery based sequence is commonly used to achieve suppression of healthy myocardium signal. However, the blood pool and subendocardial scar typically have similar signal, making it difficult to distinguish subendocardial scar. In this work, we propose a novel pulse sequence that uses an optimized combination of an inversion pulse and a T2prep composite pulse to simultaneously null both the healthy myocardium and blood signals, producing a black-blood LGE (BB-LGE) image without losing significant scar-myocardium contrast.

12 0185.
"Squashing the peanut": What it means for in-vivo cardiac DTI
Andrew D Scott1,2, Sonia Nielles-Vallespin1,3, Pedro Ferreira1,2, Laura-Ann McGill1,2, Dudley Pennell1,2, and David Firmin1,2
1NIHR Cardiovascular Biomedical Research Unit, The Royal Brompton Hospital, London, United Kingdom, 2National Heart and Lung Institute, Imperial College London, London, United Kingdom, 3National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States

The effects of noise have been well described in neurological DTI, but the specific effects on cardiac DTI are less understood. We developed cardiac specific simulations to demonstrate the effects of noise on parameters derived from cardiac DTI at a range of b-values. This framework was used to demonstrate the benefits of averaging the complex rather than magnitude data. Subsequently, an algorithm for complex averaging of in-vivo data was developed and tested in a healthy cohort. FA and MD are over-estimated at low b-values and under-estimated at high b-values. Complex averaging reduces under-estimation of MD and FA at high b-values.

13 0186. Diffusion-tensor imaging study of myocardial architecture of Situs Inversus and Situs Solitus mutant mouse hearts
Yijen Lin Wu1,2, Yu Chen1, XiaoQin Liu1, Fang-Cheng Yeh3, T. Kevin Hitchens4, George C Gabriel1, and Cecilia Wen Ya Lo1
1Developmental Biology, University of Pittsburgh, Pittsburgh, PA, United States, 2Rangos Research Center Imaging Core, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, United States, 3Psychology, Carnegie Mellon University, Pittsburgh, PA, United States, 4Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, PA, United States

Normal human development results in an asymmetrical arrangement of the organs within the chest and abdomen, as referred to as Situs Solitus. Situs Inversus, a type of laterality defect, in which the organs of the chest and abdomen are arranged in a perfect mirror image reversal of the normal position. We used DTI to study the myocardial architecture of Pkd1l1-/- mutant mouse hearts, with either Situs Solitus or Situs Inversus phenotypes. Although the Situs Solitus mutant heart appears phenotypically “normal”, our DTI results show that it is showing more aberrant myocardial organization similar to those of Situs Inversus mutant heart.

14 0187.
Mechanical Activation Time Mapping in Heart Failure Patients with and without Myocardial Scar using Cine DENSE MRI
Daniel A Auger1, Sophia X Cui1, Xiao Chen1, Jeffrey W Holmes1, Kenneth C Bilchick2, and Frederick H Epstein1,3
1Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, United States, 2Department of Medicine, Cardiovascular Medicine, University of Virginia, Charlottesville, Virginia, United States, 3Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, United States

The purpose of this study was to use MRI and other methods to evaluate the relationship between mechanical and electrical cardiac activation in patients with heart failure (HF), a wide QRS complex, and the absence or presence of myocardial scar. Cine DENSE MR strain imaging methods were used to assess the delay in mechanical activation time in patients with and without scar. Results show good correlations between mechanical and electrical activation times in both patient cohorts. In patients with scar, the steeper slope of the regression line may reflect a more complex electromechanical substrate and altered electro-mechanical coupling.

15 0188. A Bayesian Approach for Accelerated Phase Contrast MRI
Adam Rich1, Lee C. Potter1, Ning Jin2, Joshua Ash1, Orlando Simonetti3, and Rizwan Ahmad3
1Electrical and Computer Engineering, The Ohio State University, Columbus, OH, United States, 2Siemens Medical Solution, Columbus, OH, United States, 3Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States

Phase Contrast MRI (PC-MRI) offers unique advantages over Doppler ultrasound for the quantification of hemodynamics. However, lengthy scan times have limited the clinical use of PC-MRI. We propose a Bayesian inference technique to accelerate PC-MRI data acquisition. The technique exploits the rich structure inherent to the data across space, time and encodings. Using 2D PC-MRI data from healthy volunteers, performance of the technique is examined over a wide range of acquisition times for prospective and retrospective under-sampling. The proposed technique provides an accurate recovery of peak and mean velocity at accelerate rates of eight or higher with fast computation.

16 0189. Validation of radially undersampled 4D-Flow-MRI in an animal model of portal hypertension
Alex Frydrychowicz1, Alejandro Roldan-Alzate2, Emily Winslow2, Dan Consigny2, Camilo Campo2, Utaroh Motosugi2, Kevin M Johnson2, Christopher J François2, Oliver Wieben2, and Scott B Reeder2
1Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Hosltein, Campus Lübeck, Lübeck, Schleswig-Holstein, Germany, 2University of Wisconsin - Madison, Wisconsin, United States

An animal model of portal hypertension by partial portal vein ligature was created in seven pigs and evaluated by 4D Flow MRI using PC-VIPR, a radially undersampled acquisition scheme. During the operative procedure, vessels were assessed by perivascular ultrasound to provide an unprecedented in-vivo comparison of 4D Flow MRI to a reference standard. PHTN was successfully created, results show a good agreement of US and 4D Flow MRI using PC-VIPR.