HuaLei Zhang¹, Zion Tsz ho Tse², Charles L. Dumoulin³, Ronald Watkins⁴, Wei Wang¹, Jay Ward⁵, Raymond Kwong¹, William Stevenson¹, and Ehud J. Schmidt^1
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.

Yolanda Georgia Koutraki^1,2, Chengjia Wang^1,3, Jennifer Robson², Olivia Mcbride², Rachael O. Forsythe², Tom J. MacGillivray¹, Calum D. Gray¹, Keith Goatman³, J. Camilleri-Brennan², David E. Newby^1,2, and Scott I. Semple^1,2
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.

Luca Biasiolli^1,2, Joshua T Chai¹, Linqing Li³, Ashok Handa⁴, Peter Jezzard³, Robin P Choudhury¹, and Matthew D Robson^2
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.

Jerome Yerly^1,2, Giulia Ginami^1,2, Giovanna Nordio^1,2, and Matthias Stuber^1,2
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.

Devavrat Likhite¹, Promporn Suksaranjit², Chris McGann², Brent Wilson², Imran Haider², Ganesh Adluru¹, and Edward DiBella^1
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.

Christoph Forman¹, Christoph Tillmanns², Michael O. Zenge¹, and Michaela Schmidt^1
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.

Ziwu Zhou¹, Fei Han¹, Stanislas Rapacchi¹, Ihab Ayad², Isidro Salusky³, Adam Plotnik¹, Paul Finn¹, and Peng Hu^1
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.

Jeffrey H Maki¹, Noah Briller¹, Peter C Neligan², and Gregory J Wilson^1
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.

Christos G. Xanthis^1,2, Sebastian L. Bidhult¹, Georgios Kantasis^1,2, Mikael Kanski¹, Einar Heiberg^1,3, Håkan Arheden¹, and Anthony H. Aletras^1,2
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.

Shams Rashid¹, Stanislas Rapacchi¹, Kalyanam Shivkumar^1,2, Adam Plotnik¹, J. Paul Finn^1,3, and Peng Hu^1,3
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.

Tamer Basha¹, Sébastien Roujol¹, Kraig V. Kissinger¹, Beth Goddu¹, Warren J. Manning^1,2, and Reza Nezafat^1
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.

Andrew D Scott^1,2, Sonia Nielles-Vallespin^1,3, Pedro Ferreira^1,2, Laura-Ann McGill^1,2, Dudley Pennell^1,2, and David Firmin^1,2
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.

Yijen Lin Wu^1,2, Yu Chen¹, XiaoQin Liu¹, Fang-Cheng Yeh³, T. Kevin Hitchens⁴, George C Gabriel¹, and Cecilia Wen Ya Lo^1
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.

Daniel A Auger¹, Sophia X Cui¹, Xiao Chen¹, Jeffrey W Holmes¹, Kenneth C Bilchick², and Frederick H Epstein^1,3
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.

Adam Rich¹, Lee C. Potter¹, Ning Jin², Joshua Ash¹, Orlando Simonetti³, and Rizwan Ahmad^3
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.

Alex Frydrychowicz¹, Alejandro Roldan-Alzate², Emily Winslow², Dan Consigny², Camilo Campo², Utaroh Motosugi², Kevin M Johnson², Christopher J François², Oliver Wieben², and Scott B Reeder^2
1Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Hosltein, Campus Lübeck, Lübeck, Schleswig-Holstein, Germany, ²University of Wisconsin - Madison, Wisconsin, United States