Guoxi Xie¹, Hanwei Chen², Zhuonan He², Jianke Liang², Xueping He², Qi Yang^3,4, Xin Liu¹, Debiao Li³, and Zhaoyang Fan^3
1Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China, People's Republic of, ²Department of Radiology, Guangzhou Panyu Central Hospital, Guangzhou, China, People's Republic of, ³Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ⁴Xuanwu Hospital, Beijing, China, People's Republic of

Deep vein thrombosis (DVT) is a common but elusive illness that can lead to fatal pulmonary embolism and sudden death. Effective treatment of DVT requires accurate evaluation of thrombus distribution and stage. n this work, we further accommodated the DANTE-SPACE technique to the deep vein system and conducted preliminary clinical validation. Experiment results demonstrated that DANTE-SPACE could provide excellent venous blood signal suppression and definitive thrombus detection and the technique may outperform conventional SPACE, MPRAGE, and and become a non-contrast alternative to CEMRV for the diagnosis of DVT.

Simon Reiss¹, Axel Joachim Krafft^1,2,3, Marius Menza¹, Constantin von zur Mühlen⁴, and Michael Bock^1
1Dept. of Radiology - Medical Physics, University Medical Center Freiburg, Freiburg, Germany, ²German Cancer Consortium (DKTK), University Medical Center Freiburg, Heidelberg, Germany, ³German Cancer Research Center (DKFZ), Heidelberg, Germany, ⁴Department of Cardiology and Angiology I, University Heart Center, Freiburg, Germany

Black-blood preparation is a tool for improved contrast generation in cardiovascular MRI to assess vessel wall constitution, to delineate plaques and to characterize myocardial tissue. Conventionally, black-blood MRI can be done with dual inversion recovery pulses so that selective signal nulling of the inflowing blood is achieved. The inversion delays required to establish the black-blood contrast can be favorably integrated into ECG-triggered diastolic cardiac measurements, but they are by far too time-consuming for dynamic measurements that cover the total cardiac cycle. In this work we investigate the use of conventional saturation pulses for black-blood imaging. We propose a very time-efficient pulse implementation that combines the saturation and the imaging RF pulse into a single pulse structure and enables black-blood contrast in dynamic measurements.

Lea Schroeder¹, Jens Wetzl^1,2, Andreas Maier^1,2, Lars Lauer³, Jan Bollenbeck⁴, Matthias Fenchel³, and Peter Speier^3
1Pattern Recognition Lab, Department of Computer Science, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany, ²Erlangen Graduate School in Advanced Optical Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany, ³Magnetic Resonance, Product Definition and Innovation, Siemens Healthcare GmbH, Erlangen, Germany, ⁴Magnetic Resonance, Research and Development, Hardware, Siemens Healthcare GmbH, Erlangen, Germany

We evaluate the information content of externally generated Pilot Tone signals, received with standard MR local coils, with respect to cardiac motion. Free-breathing and breathhold fluoroscopic measurements were performed with applied electrocardiogram leads to provide ground truth. Average mean correlation between RR intervals of our method and the ground truth was 0.95. Our early results indicate that locally generated PT signals contain information about cardiac motion and suggest that the proposed method could be developed into an electrocardiogram replacement by providing a continuous signal for retrospective gating with minimal hardware requirements.

Jens Wetzl^1,2, Felix Lugauer¹, Michaela Schmidt³, Andreas Maier^1,2, Joachim Hornegger^1,2, and Christoph Forman^3
1Pattern Recognition Lab, Department of Computer Science, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany, ²Erlangen Graduate School in Advanced Optical Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany, ³Magnetic Resonance, Product Definition and Innovation, Siemens Healthcare GmbH, Erlangen, Germany

We present a method for free-breathing, isotropic 3-D CINE imaging of the whole heart, demonstrated with experiments in 7 healthy volunteers. Respiratory information for retrospective gating is derived directly from the imaging data. Ventricular function parameters were compared to reference 2-D CINE acquisitions. Excellent image quality and match to ground truth ventricular function parameters could be achieved in an acquisition time similar to multi-slice 2-D CINE with equivalent coverage. Cartesian sampling combined with dual-GPU acceleration enabled a fast reconstruction in under 5 minutes for left-ventricular and under 7 minutes for whole heart coverage.

Jessica Webb¹, Ondrej Holub¹, Rachel Clough¹, Gerald Carr-White², Reza Razavi¹, and Ralph Sinkus^1
1King's College London, London, United Kingdom, ²Guys and St Thomas' NHS Trust, London, United Kingdom

Heart Failure with preserved Ejection Fraction (HFpEF) is common and associated with high morbidity and mortality. There are challenges in diagnosing HFpEF and a non invasive technique to detect myocardial stiffness would have an enormous clinical impact.  

 

We have developed a novel non invasive technique to quantify myocardial stiffness in vivo using transient Magnetic Resonance Elastography (tMRE). The technique relies on accurately identifying the aortic valve closure time. The speed of the propagating shear wave, created by the valve closure, is measured using a short navigated free breathing MRI sequence. Increased myocardial stiffness results in increased speed of shear wave propagation.  

David F A Lloyd^1,2, Bernhard Kainz³, Joshua F P van Amerom¹, Kuberan Pushparajah^1,2, John M Simpson², Vita Zidere², Owen Miller², Gurleen Sharland², Tong Zhang¹, Maelene Lohezic¹, Joanne Allsop¹, Matthew Fox¹, Christina Malamateniou¹, Mary Rutherford¹, Jo Hajnal¹, and Reza Razavi^1,2
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, ²Evelina Children's Hospital, London, United Kingdom, ³Department of Computing (BioMedIA), Imperial College London, London, United Kingdom

The diagnosis of potentially life-threatening vascular abnormalities in the fetus can be difficult with ultrasound alone. MRI is one of the few safe alternative imaging modalities in pregnancy; however to date it has been limited by unpredictable fetal and maternal motion during acquisition. We present six antenatal cases, four with important structural congenital heart disease, in which we employed a novel algorithm for motion-corrected slice-volume registration, producing a navigable 3D volume of the fetal thoracic vasculature. The anatomical findings in each case were then correlated to fetal echocardiographic findings, and finally displayed as interactive surface rendered models.

Terrence Jao¹ and Krishna Nayak^2
1Biomedical Engineering, University of Southern California, Los Angeles, CA, United States, ²Electrical Engineering, Los Angeles, CA, United States

Advances in MR hardware, pulse sequences, and calibration have made quantitative CMR a reality. Quantitative maps (e.g. T1, T2, ECV) are formed from multiple images, which make them susceptible to errors caused by signal fluctuations from cardiac or respiratory motion, termed physiological noise. Reproducibility of quantitative CMR maps is critical for future clinical adoption and depends on the ratio of signal amplitude to physiological noise, termed temporal SNR. In this study, we measure temporal SNR in bSSFP quantitative CMR to characterize physiological noise for a range of image resolutions, acceleration factors, and post inversion delays. 

Ilkay Oksuz^1,2, Rohan Dharmakumar^3,4, and Sotirios A. Tsaftaris^2,5
1Diagnostic Radiology, Yale University, New Haven, CT, United States, ²IMT Institute for Advanced Studies Lucca, Lucca, Italy, ³Biomedical Imaging Research Institute, Cedars Sinai Medical Center, Los Angeles, CA, United States, ⁴University of California, Los Angeles, CA, United States, ⁵The University of Edinburgh, Edinburgh, United Kingdom

Cardiac Phase-resolved Blood Oxygen-Level-Dependent (CP-BOLD) MRI is a new contrast and stress-free approach for detecting myocardial ischemia, that identifies the ischemic myocardium by examining changes in myocardial signal intensity patterns as a function of cardiac phase. But, these changes coupled with cardiac motion, challenge automated standard CINE MR myocardial segmentation and registration techniques resulting in a significant drop of segmentation and registration accuracy. We propose a dictionary learning based multi-resolution registration scheme for supervised learning and sparse representation of the myocardium. Our results show an improvement of 15% myocardial segmentation w.r.t. the state of the art. 

Zhengwei Zhou^1,2, Yuhua Chen³, Yibin Xie¹, Christopher Nguyen¹, Mu Zeng⁴, James Dawkins⁵, Zhanming Fan⁴, Eduardo Marbán⁵, and Debiao Li^1,2,5
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ²Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States,³Department of Computer and Information Science, University of Pennsylvania, Philadelphia, PA, United States, ⁴Department of Radiology, Anzhen Hospital, Capital Medical University, Beijing, China, People's Republic of, ⁵Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States

In this work, we developed an optimized cardiac CEST method to detect myocardial metabolic change with significantly reduced scan time. Our initial results in porcine model with chronic myocardial infarction show that scar region has lower metabolic activity compared to healthy myocardium, using LGE as reference. This study also shows the feasibility of cardiac CEST imaging in a patient, for the first time. 

Yan Wen¹, Thanh D. Nguyen², Zhe Liu¹, Pascal Spincemaille², Dong Zhou², Alexey Dimov¹, Youngwook Kee², Jiwon Kim³, Jonathan W. Weinsaft³, and Yi Wang^1,2
1Biomedical Engineering, Cornell University, New York, NY, United States, ²Physics in Radiology, Weill Cornell Medicine, New York, NY, United States, ³Medicine, Weill Cornell Medicine, New York, NY, United States

Quantitative Susceptibility Mapping (QSM) has yet to be applied on cardiac patients due to the challenges from motion artifacts and background fields. In this first attempt to apply QSM in cardiac MRI, we overcome these data acquisition and processing challenges by using robust graph cut phase analysis and a novel preconditioned inversion of total field. Our preliminary results demonstrate high quality susceptibility maps, and the measured heart chamber blood oxygenation level is consistent with reported values from literature.