Jessica AM Bastiaansen^1,2, Davide Piccini³, and Adele Mackowiak^4
1Department of Diagnostic, Interventional and Pediatric Radiology (DIPR), Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland, ²Translational Imaging Center, sitem-insel, Bern, Switzerland, ³Advanced Clinical Imaging Technology, Siemens Healthcare, Lausanne, Switzerland, ⁴Department of Radiology, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland

Flexible off-resonant RF pulse designs such as LIBRE and BORR are inspired by conventional binomial 1-(180)-1 water excitation pulses and perform better in terms of fat suppression. To abbreviate scanning times, BORR and LIBRE pulse durations can be shortened by increasing the RF excitation frequency at the expense of increased RF power. To reduce RF power, we developed a novel off-resonant RF pulse design based on the conventional 1-(90)-1 water excitation pulse.  LIBOR, compared with LIBRE and BORR, reduced the required RF power while maintaining short pulse durations and effective fat suppression in simulations, knee, and cardiac MRI at 3T.

Ehud Jeruham Schmidt¹, Mirko Hrovat², Henry R Halperin¹, and Aravindan J Kolandaivelu^1
1Medicine (Cardiology), Johns Hopkins University, School of Medicine, Baltimore, MD, United States, ²Mirtech Inc., Boston, MA, United States

A resistive-shim system was constructed to correct the >100ppm magnetic-field inhomogeneity caused by implanted ICDs, which leads to signal loss and blurring in cardiac MRI. A plastic platform, held to the MRI stretcher, allows human-subject insertion, and holds a sensitive 720 Ampere*turns dipole-approximating shim-coil on a movable-fixture above the chest. Shim-coil is electronically decoupled from gradients and body-coil-RF. ICD field-inhomogeneity is measured with B0 mapping, and a correction field computed (shim-coil-center-location, DC-current-intensity). Shim-coil is moved to shim-coil-center-location, and a power-supply sends DC-current to the shim-coil. System was tested on phantoms overlaid with ICDs and corrected >75ppm inhomogeneity over 50x50x50mm³ FOV.

Ronald Mooiweer^1,2, Rainer Schneider³, Axel Joachim Krafft³, Katy Empanger⁴, Jason Stroup⁴, Alexander Paul Neofytou¹, Rahul K Mukherjee¹, Steven Williams^1,5, Tom Lloyd⁴, Mark O'Neill¹, Reza Razavi¹, Tobias Schaeffter⁶, Radhouene Neji^1,2, and Sébastien Roujol^1
1School of Biomedical Engineering and Imaging Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom, ²MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom, ³Siemens Healthcare GmbH, Erlangen, Germany, ⁴Imricor Medical Systems, Burnsville, MN, United States, ⁵University of Edinburgh, Edinburgh, United Kingdom, ⁶Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany

Continuous AT was used for cardiac synchronization of MR-thermometry with on-line signal filtering, calibration, and triggering. Experiments in a porcine animal model, where AT-trig was compared to ECG triggering, showed that AT-trig could potentially serve as alternative cardiac triggering strategy in situations where ECG triggering is not effective.

Katerina Eyre¹, Michael Chetrit¹, Lisa Leroi², Jérôme Yerly^3,4, Mitchel Benovoy², Davide Piccini^3,5, Matthias Stuber^3,4, Matthias Friedrich^1,2,6,7,8, and Jessica AM Bastiaansen^3,9,10
1Radiology, McGill University Health Centre (MUHC), Montreal, QC, Canada, ²Circle Cardiovascular Imaging Inc., Calgary, AB, Canada, ³Diagnostic and Interventional Radiology, Le Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland, ⁴Center for BioMedical Imaging (CIBM), Lausanne, Switzerland, ⁵Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland, ⁶Radiology, Université de Montréal, Montreal, QC, Canada, ⁷Cardiac Sciences, University of Calgary, Calgary, AB, Canada, ⁸Heidelberg University, Heidelberg, Germany, ⁹Diagnostic, Interventional and Pediatric Radiology (DIPR), Inselspital, Bern University Hospital, Bern, Switzerland, ¹⁰Translational Imaging Cente, Bern, Switzerland

Cardiac magnetic resonance imaging is often limited by long scan times and the need for multiple breath holds. A Free-Running sequence may overcome this limitation by providing 3-D cine data in a free-breathing non-ECG-triggered acquisition of 7 minutes. The clinical applicability of this method was tested in a cohort of 9 patients with varying pathologies. Myocardial blood-pool volumes and ejection fractions were compared between standard 2-D protocols and 5-D Free-Running-LIBRE. Free-Running-LIBRE successfully quantified volumes and ejection fractions with results correlating strongly to reference measurements. The method demonstrated additional potential to visualize irreversible myocardial injury in these patients. 

Oluyemi Aboyewa^1,2, KyungPyo Hong², Fuchang Jiang¹, Bhumi Bhusal², Giorgio Bonmassar³, Andrada Popescu⁴, Gregory Webster⁵, Laleh Golestanirad^1,2, and Daniel Kim^1,2
1Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, United States, ²Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States, ³AA. Martinos Center Massachusetts General Hospital Harvard Medical School, Charlestown, MA, United States, ⁴Department of Medical Imaging, Ann & Robert H. Lurie Children's Hospital, Chicago, IL, United States, ⁵Division of Cardiology, Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital, Chicago, IL, United States

This study investigated whether wideband late-gadolinium enhancement (LGE) and T1 mapping pulse sequences can suppress image artifacts induced by an ICD positioned 12cm inferior to the heart in a pediatric anthropomorphic phantom. The ICD induced a peak-to-peak center frequency shift of 970Hz across the heart. The normalized mean signal intensity within the heart was 1.91±1.20 and 0.98±0.39, for standard and wideband LGE with ICD, respectively. The mean myocardial T1 was 1486.1±607.7 and 1728.3±332.3msec for standard and wideband T1 mapping, respectively. Our results demonstrate that wideband pulse sequences can suppress image artifacts induced by an ICD in a pediatric anthropomorphic phantom.

Thomas Wilhelm Eigentler^1,2, Bilguuun Nurzed¹, Andre Kuehne³, and Thoralf Niendorf^1,3,4
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany, ²Technische Universität Berlin, Chair of Medical Engineering, Berlin, Germany, ³MRI.TOOLS GmbH, Berlin, Germany, ⁴Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine, Berlin, Germany

The gain in signal-to-noise ratio is driving the ultrahigh field and extreme field MRI. This work highlights the opportunities and electromagnetic constraints of realistic radiofrequency array concepts tailored for cardiovascular MRI at 7.0T, 10.5T, and 14.0T. For this purpose electromagnetic field simulations were performed using 32, 48 and 64-channel RF transceiver array configurations at 7.0T, 10.5T, and 14.0T. Our findings demonstrate, that a higher channel count increases the degrees of freedom of B₁⁺ shaping. Furthermore, the preliminary results provide a strong mandate for static PTX or even dynamic PTX tailored at the heart at 10.5T and 14.0T.

Ali Caglar Özen¹, Johannes Fischer¹, Simon Reiss¹, Thomas Lottner¹, Alexander Maier², Waldemar Schimpf³, Timo Heidt², Constantin von zur Mühlen², and Michael Bock^1
1Dept. Radiology, Medical Physics, Medical Center - University of Freiburg, Freiburg, Germany, ²Cardiology and Angiology I, Heart Center Freiburg University and Faculty of Medicine, Freiburg, Germany, ³Neurozentrum, Wissenschaftliche Werkstätten, Medical Center - University of Freiburg, Freiburg, Germany

In this study, we have developed an 8-channel transmit/ 8-channel receive coil array system for cardiac and thoracic MRI in pigs. Transmit array is scalable in size to increase transmit efficiency in pigs with smaller abdomen size. Receive array is semi-flexible to fit tightly on the dome-shaped thorax of pigs. We present a detailed transmit efficiency analysis of the Tx array including tolerance to mismatches at the input ports. We also present 19F MRI results from a cadaver measurement.

Alina Schneider¹, Reza Hajhosseiny¹, Camila Munoz¹, Giorgia Milotta², Karl P Kunze^1,3, Radhouene Neji^1,3, Amedeo Chiribiri¹, Pier Giorgio Masci¹, René M Botnar¹, and Claudia Prieto^1
1School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, ²Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom, ³MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom

3D whole-heart free breathing water/fat non-rigid motion corrected grey-blood PSIR LGE technique has been recently proposed showing good agreement with conventional 2D grey-blood LGE MRI. Due to the relatively long scan time of ~10 minutes, contrast washout may influence scar detection and limit spatial resolution. Here we compare the proposed 3D grey-blood PSIR LGE after slow infusion and bolus injection at high isotropic spatial resolution to evaluate the benefit of the slow infusion injection. Both pipelines were compared to the conventional breath-held 2D grey blood PSIR-LGE imaging technique. Overall higher quality scores were observed in images acquired after slow infusion.

Alina Schneider¹, Camila Munoz¹, Alina Hua¹, Karl P Kunze^1,2, Radhouene Neji^1,2, Tevfik F Ismail¹, René M Botnar¹, and Claudia Prieto^1
1School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, ²MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom

 Simultaneous ¹⁸F-FDG PET-MRI has shown promise for improved diagnostic accuracy of inflammatory cardiac diseases. However, respiratory motion and mis-registration between free-breathing 3D PET and 2D breath-held MR images remain challenges that have hindered its clinical adoption. We have recently proposed a free-breathing non-rigid motion-compensated 3D whole-heart T₂-mapping that enables detection of myocardial inflammation and provides non-rigid respiratory motion fields to correct simultaneously acquired PET data in a 3T PET-MR system. Here, we perform a preliminary clinical validation of this approach in 8 patients with suspected cardiovascular disease. Good image quality with T₂ values comparable to clinical 2D T₂-mapping was achieved.

Maxime Yon^1,2, Marylène Delcey^1,2, Pierre Bour^1,2, William Grissom³, Bruno Quesson^1,2, and Valéry Ozenne^1,2
1Electrophysiology and Heart Modeling Institute, Pessac, France, ²U1045, Centre de Recherche Cardio-Thoracique de Bordeaux Inserm, Bordeaux, France, ³Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States

Interventional MR thermometry has the potential to increase the success rate of the radio-frequency cardiac ablative procedure by allowing real-time monitoring of the lesion growth. Available methods are dependent on ECG-gating, which is poorly reliable in arrhythmic conditions. We propose a new approach based on radial continuous gradient echo acquisition combined with concomitant 2D intra-scan motion correction and direct estimation of the temperature from k-space data which could be a robust alternative to the more classical but ECG-triggered and artifact-prone EPI methods.

Jie Xiang¹, Jerome Lamy², Rachel Lampert³, and Dana C. Peters^1,2
1Department of Biomedical Engineering, Yale University, New Haven, CT, United States, ²Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States, ³Department of Medicine, Cardiovascular Division, Yale University, New Haven, CT, United States

Interleaved undersampled radial linear-combination balanced SSFP (LC-SSFP) was investigated as a method for improving cardiac cine images, acquired in subjects with metallic implants. Phantoms and healthy volunteer studies were performed, in the presence of metallic artifacts (generated by a stainless steel bolt). We found the proposed method eliminated some artifacts seen using standard Cartesian bSSFP. These findings may lead to improved cardiac cine imaging for patients with a pacemaker or implantable cardioverter defibrillator (ICD).

Zhan-Qiu Liu^1,2, Nyasha Maforo³, Pierangelo Renella³, Nancy Halnon³, Holden Wu³, and Daniel Ennis^4
1Cardiovascular Institute, Stanford University, Mountain View, CA, United States, ²Department of Radiology, Stanford University, Stanford, CA, United States, ³University of California, Los Angeles, Los Angeles, CA, United States, ⁴Stanford University, Mountain View, CA, United States

Left ventricular (LV) peak mid-wall circumferential strain (E_cc) and twist are early biomarkers for evaluating the subtle and highly variable onset and progression of cardiomyopathy in pediatric subjects with Duchenne muscular dystrophy (DMD). Cine Displacement Encoding with Stimulated Echoes (DENSE) has proven sensitive to changes in E_cc and twist, but has not been reported in a DMD cohort. We show that free-breathing DENSE CMR at 3T provides highly reproducible middle-ventricular E_cc, radial strain (E_rr), and twist measurements in healthy boys and boys with DMD without evidence of late gadolinium enhancement.

Stefano Buoso¹, Thomas Joyce¹, and Sebastian Kozerke^1
1Institute of Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland

We propose to augment MRXCAT with left-ventricular anatomies and function, representing realistic population statistics, to enable design and validation of CMR imaging and inference approaches. A variational autoencoder is deployed to identify parametric anatomical representations from a cohort of healthy and diseased anatomies to allow for the generation of new synthetic anatomies. Cardiac function is simulated using a biophysical model also incorporating local tissue defects. The resulting ventricular tissue masks are enriched with background information from XCAT. Synthetic MR images are generated using MRXCAT, making available paired data of CMR images and (patho)physiological parameters including ground-truth ventricular strains and displacements.

Jinyang Wen¹, Xin Zhang¹, Lianggeng Gong¹, Jiankun Dai², and Long Qian^2
1Radiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China, ²MR Research, GE Healthcare, Beijing, China

Heart failure with preserved ejection fraction（HFpEF）was evaluated by echocardiography commonly. In this study, we try to use Cardiovascular Magnetic Resonance Tissue-Tracking (CMR-TT) to assess left atrial (LA) function in hypertension patients (HP) with left ventricular diastolic dysfunction (LVDD). The results demonstrated that LA myocardial function decreased in HP with LVDD. LA myocardial strain parameters could detect sensitively the myocardial deformation of LVDD in HP. Total strain(εs) parameter was an excellent parameter for diagnose HFpEF and evaluating the degree of LVDD.

Fayez Habach^1,2, Jennifer Barry³, Melissa Larsen³, Marne Jamieson⁴, Amit Singnurkar⁵, Michael Laflamme⁶, and Nilesh Ghugre^1,2
1Medical Biophysics, University of Toronto, Toronto, ON, Canada, ²Physical Sciences, Sunnybrook Research Institute, Toronto, ON, Canada, ³Schulich Heart Research Program, Sunnybrook Research Institute, Toronto, ON, Canada, ⁴Nuclear Medicine, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, ⁵Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, ⁶Mcewen Stem Cell Institute, University Health Network, Toronto, ON, Canada

Hybrid PET/MRI is a promising tool that can characterize both metabolic and structural information and has been used extensively in the context of MI-related heart failure. We propose a novel dual-condition protocol that can be used to characterize metabolic state of cardiac tissue in vivo following MI, under different substrate conditions. Our results show significant metabolic changes under fasting and glucose loading conditions, and further longitudinal differences in MI-related metabolic remodeling within both the infarct zone and surrounding myocardium. This framework has potential to be used in testing therapeutic efficacy following MI in both preclinical and clinical contexts.