View Presentation Video

Pierre Daudé^1,2, Thomas Troalen³, Adèle L C Mackowiak^4,5,6, Emilien Royer^1,2, Davide Piccini^4,7, Jérôme Yerly^4,8, Josef Pfeuffer⁹, Frank Kober^1,2, Sylviane Confort Gouny^1,2, Monique Bernard^1,2, Matthias Stuber^4,8, Jessica A M Bastiaansen^5,6, and Stanislas Rapacchi^1,2
1Aix-Marseille Univ, CNRS, CRMBM, Marseille, France, ²APHM, Hôpital Universitaire Timone, CEMEREM, Marseille, France, ³Siemens Healthcare SAS, Saint-Denis, France, ⁴Department of Diagnostic and Interventional Radiology, Lausanne University Hospital, Lausanne, Switzerland, ⁵Department of Diagnostic, Interventional and Pediatric Radiology (DIPR), Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland, ⁶Translation Imaging Center (TIC), Swiss Institute for Tranlational and Entrepreneurial Medicine, Bern, Switzerland, ⁷Advanced Clinical Imaging Technology, Siemens Healthineers International AG, Lausanne, Switzerland, ⁸Center for Biomedical Imaging, Lausanne, Switzerland, ⁹Siemens Healthcare, MR Application Development, Erlangen, Germany

Keywords: Fat, Quantitative Imaging

Free-running cardiac Dixon-MRI has the potential for motion-resolved R₂* and PDFF quantification to explore cardiac fat accumulation and alteration in metabolic diseases. This study combines a self-navigated 3D radial sequence with 13 echoes using fast bipolar signal-readouts, a k-space trajectory correction, a compressed sensing reconstruction, and IDEAL fat-water separation to obtain precise ( limits of agreement: ±1.2 % and 5.0 s^-1) and highly spatially and motion-resolved quantitative PDFF and R₂* maps of the whole heart. We report here the first in vivo characterization of metabolically-active epicardial fat (PDFF: 81.6±9.6 %), distinct from adjacent paracardial fat.

View Presentation Video

Christopher A. Rock^1,2, Iris Y. Chen², Anne L. Philip¹, Boris Keil^2,3, Christopher T. Nguyen^2,4,5, and David E. Sosnovik ^1,2,5
1Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, United States, ²A.A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, ³Institute of Medical Physics and Radiation Protection, TH Mittelhessen University of Applied Sciences, Giessen, Germany, ⁴Cardiovascular Innovation Research Center, Heart, Vascular, and Thoracic Institute, Cleveland Clinic, Cleveland, OH, United States, ⁵Health Sciences and Technology Program, Harvard - Massachusetts Institute of Technology, Cambridge, MA, United States

Keywords: Myocardium, Diffusion Tensor Imaging

This study describes a method to acquire submillimeter resolution diffusion tensor MRI scans of the human heart in vivo. Imaging was performed in healthy controls and patients with severe high flow-high gradient aortic stenosis. The images were processed to generate helix angle maps of cardiomyocyte orientation and compared. The range of helix angles across the myocardium was higher in subjects with aortic stenosis and the relative helix angle slope was also increased in patients with aortic stenosis.

View Presentation Video

Ajay Peddi¹, Daniel Schache¹, Ali Nahardani², Michael Kuhlmann³, Moritz Wildgruber^1,4, Cornelius Faber¹, and Verena Hoerr^1,2
1Translational Research Imaging Center, Clinic of Radiology, University of Münster, Münster, Germany, ²Heart Center Bonn, Department of Internal Medicine II, University Hospital Bonn, Bonn, Germany, ³European Institute for Molecular Imaging, University of Münster, Münster, Germany, ⁴Clinic and Polyclinic for Radiology, University Hospital of München, München, Germany

Keywords: Myocardium, CEST & MT

The current preclinical study aimed to explore the application of natural D-glucose as an infusible biodegradable MRI contrast agent for imaging of myocardial infarction (MI) by glucose weighted CEST MRI (glucoCEST). To this end, in a mouse model of MI, the infarct region was first identified and verified by late gadolinium enhancement MRI and histology, respectively. In-Vivo glucoCEST MTRasym maps showed substantial differences before and after glucose infusion according to the myocardial viability. Statistical analysis verified that glucoCEST contrast could distinguish significantly between MI region, remote myocardium as well as healthy myocardium.

Cyril Tous^1,2, Guillaume Flé³, Matthew McGarry⁴, Philip Bayly⁵, Keith Paulsen^4,6, Curtis Johnson⁷, Matthias Stuber^1,2, and Elijah Van Houten^8
1Diagnostic and Interventional Radiology, Lausanne University Hospital (CHUV), Lausanne, Switzerland, ²Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, ³Université de Montréal, Montréal, QC, Canada, ⁴Thayer school of engineering, Dartmouth College, Hanover, NH, United States, ⁵McKelvey School of Engineering, Washington University, Saint Louis, MO, United States, ⁶Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States, ⁷Biomedical Engineering, University of Delaware, Newark, DE, United States, ⁸Mechanical Engineering, Université de Sherbrooke, Sherbrooke, QC, Canada

Keywords: Heart, Elastography

MR elastography (MRE) must account for the anisotropic nature of myocardial tissue to accurately quantify stiffness. The constitutive matrix for this material was rotated to align with the fibers. One ex vivo swine heart was scanned with DTI and MRE sequences at 2  isotropic voxel resolution. Transversely isotropic viscoelastic stiffness was reconstructed using the Non-Linear Inversion (NLI) algorithm. Elastic properties (shear and Young’s modulus, tensile and shear anisotropy) were segment dependent, in agreement with the myocyte sheetlet formation, which varies in size and spacing according to the myocardial segment. Similarities between MRE and DTI metrics could be observed.

Maximilian Gram^1,2, Petra Albertova^1,2, Fabian Tobias Gutjahr², Peter Michael Jakob², Wolfgang Rudolf Bauer^3,4, Peter Nordbeck^1,4, and Martin Christa^1,4
1Department of Internal Medicine I, University Hospital Würzburg, Würzburg, Germany, ²Experimental Physics 5, University of Würzburg, Würzburg, Germany, ³Department of Internal Medicine I, Divisions of Cardiology and Nephrology, University Hospital Würzburg, Würzburg, Germany, ⁴Comprehensive Heart Failure Center (CHFC), Würzburg, Germany

Keywords: Relaxometry, Quantitative Imaging, Spin-Lock, T1ρ, T2ρ

In this work, we propose myocardial T_2ρ mapping as a potential and more robust alternative to conventional T₂ quantification. Our new approach for T_2ρ imaging, which is based on Malcolm-Levitt preparations with zero inter-pulse delays, was compared with established pulse sequences for T₂, T_1ρ and T_2ρ in both phantom and in vivo experiments. In summary, the new preparatory pulse sequence was shown to meet the demanding requirements of myocardial T_2ρ mapping at high magnetic field strength and to outperform conventional T_2ρ preparations using balanced spin-locking.

View Presentation Video

Yupeng Zhao¹, Rie Beck Olin¹, Esben Søvsø Szocska Hansen², Christoffer Laustsen², Jan Henrik Ardenkjær-Larsen¹, and Lars G. Hanson^1,3
1Technical University of denmark, Kongens Lyngby, Denmark, ²MR Research Centre, Aarhus University, Aarhus, Denmark, ³Danish Research Centre for Magnetic Resonance, Hvidovre, Denmark

Keywords: Myocardium, Perfusion

As an alternative to Gadolinium, metabolically inert hyperpolarized contrast agents have been used in perfusion studies. For myocardial perfusion measurements, it is challenging to reliably obtain perfusion-related signals due to partial volume effects. We propose a constrained decomposition approach, enforcing prior knowledge of the residue function being temporally decreasing. The method is capable of separating the arterial and perfusion components and the quantified perfusion map is not visibly affected by partial volume effects.

View Presentation Video

Keywords: Myocardium, Transplantation, oxygen metabolism

Microvascular dysfunction and excessive fibrous burden are independent prognostic factors after heart transplantation. A new novel cardiovascular MR technique for the measurement of myocardial oxygen extraction fraction was evaluated for a feasibility study in 10 patients after heart transplantation. It was observed that oxygen extraction fraction was significantly correlated with myocardial extracellular volume (diffuse fibrosis indicator). Further research with more patients is warranted to explore this new CMR metabolism index for early diagnosis of cardiac dysfunction in these patient cohorts.

View Presentation Video

Anlan Hong^1,2, Kyle D. W. Vollett^1,2, Aaron M. Troy^1,2, and Hai-Ling Margaret Cheng^1,2,3
1Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada, ²Translational Biology & Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, Canada, ³The Edwards S. Rogers Sr. Department of Electrical & Computer Engineering, University of Toronto, Toronto, ON, Canada

Keywords: Inflammation, Preclinical

We report a novel nitric oxide (NO)-sensitive MRI contrast agent that holds potential for detecting endogenous NO. Type I collagen and HEK cell lysate showed strong binding with NO agent, while HSA and various ROS/RNS species showed NO agent was only activated by NO. In vivo washout rate was also tested, and NO agent cleared from mice 7 days after intraperitoneal injection. Prolonged enhancement was observed in the heart after isoproterenol injection, which indicated excess NO production and inflammation. The NO agent shows promise as a molecular imaging agent in early detection of inflammatory diseases.

 

View Presentation Video

Keywords: Myocardium, Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy with a worldwide prevalence of ~1:250.  It is the leading cause of sudden cardiac death often during exercise and in otherwise healthy, young individuals.  We applied hyperpolarized [1-¹³C]-pyruvate MRI for metabolic imaging to 3 patients with HCM using multi-slice, dynamic metabolite-specific imaging with autonomous scanning.  We observed focal metabolic abnormalities corresponding to regions of hypertrophy in patients with asymmetric non-obstructive HCM and differences in metabolism measurements compared to healthy volunteers.

View Presentation Video

Keywords: Heart, Data Processing

Bright-blood late gadolinium-enhanced (LGE) imaging is the current clinical gold standard to assess myocardial scar. However, poor contrast at the blood-scar interface makes scar detection and quantification challenging. Bright- and black-blood LGE imaging technologies have recently enabled more accurate scar detection and localization and have shown promising results for scar quantification. Here we aim to introduce a framework for fully automated scar detection and quantification combining novel joint bright- and black-blood LGE imaging with artificial intelligence-powered analysis.

View Presentation Video

Keywords: Myocardium, Tissue Characterization

T1 and T2 are well-recognized parameters for detecting various cardiomyopathies, and T1ρ is an endogenous contrast for myocardial fibrosis. Multi-parametric cardiac MRI can provide co-registered parameter maps for comprehensive diagnosis and account for the interparameter dependency for more accurate quantification. Therefore, we propose a free-breathing simultaneous T1, T2, and T1ρ mapping technique with single-shot Cartesian acquisition and dictionary matching for parameter quantification. The phantoms results indicated the good accuracy and insensitiveness to heart rates of the proposed technique. Using prospective through-plane and retrospective in-plane motion correction, the proposed method generated similar in vivo mapping quality to breath-hold mapping methods.

View Presentation Video

Keywords: Myocardium, MR Fingerprinting, Machine Learning/Artificial Intelligence

This work proposes a high-resolution (1.2x1.2x5 mm³) MR Fingerprinting method for T₁, T₂, and M₀ mapping of both left and right ventricles during a breathhold, with validation in 12 healthy subjects at 1.5T. A key component is the use of a deep image prior reconstruction for reducing noise and undersampling artifacts despite the decreased SNR when moving to higher resolution. Comparable myocardial relaxation times were measured in both ventricles (LV T₁ 1061+/-22ms, T₂ 42.2+/-3.4ms; RV T₁ 1062+/-29ms, T₂ 42.7+/-2.5ms). Higher-resolution MRF yielded slightly smaller intersubject standard deviation (SD) but larger intrasubject SD compared to a lower-resolution (1.6x1.6x8 mm³) MRF acquisition.

View Presentation Video

Masa Bozic-Iven^1,2, Stanislas Rapacchi³, Qian Tao², Lothar R. Schad¹, and Sebastian Weingärtner^2
1Heidelberg University, Mannheim, Germany, ²Delft University of Technology, Delft, Netherlands, ³University Aix-Marseille, Marseille, France

Keywords: Myocardium, Arterial spin labelling

Myocardial arterial spin labeling (myoASL) holds promise for needle-free myocardial blood flow (MBF) quantification but requires tedious averaging over multiple breath-holds. Here, free-breathing myoASL was implemented with dual-navigator gating, both with bSSFP and spoiled GRE readout. Images were processed using individual blood T₁ and inversion time correction as well as a phase-sensitive (PS) image reconstruction. Phantom results showed PS reconstruction to reduce MBF variations for short RR and T₁ values. Perfusion values were comparable with breath-held myoASL and on par with the literature. Ultimately, this can enable faster myoASL acquisitions with improved patient comfort.

View Presentation Video

Jay Bharatsingh Bisen¹, Sandra Quinn¹, Ozden Kilinc¹, Havisha Pedamallu¹, Kelvin Chow^2,3, Rachel Davids^2,3, Daniel C Lee⁴, Daniel Kim¹, Richard L Weinberg⁴, James Carr¹, Michael Markl¹, Bradley D Allen¹, and Ryan Avery^1
1Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States, ²Radiology, Northwestern University, Chicago, IL, United States, ³Siemens Healthcare, Chicago, IL, United States, ⁴Cardiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States

Keywords: Vessels, Quantitative Imaging, Quantitative Perfusion, Heart Transplant, Coronary Allograph Vasculopathy

Cardiac Allograft Vasculopathy (CAV) is a form of accelerated intimal hyperplasia in heart transplant patients that limits long-term survival. Quantitative perfusion is a novel MR imaging technique that is useful in determining myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) in CAV patients. After Rate-Pressure Product MBF corrections, Quantitative perfusion has shown that vessels with severe CAV (>70% stenosis) have significantly decreased MPR driven primarily by increased resting MBF. Quantitative perfusion may improve non-invasive monitoring of CAV status in heart transplant patients.

View Presentation Video

Keywords: Myocardium, Cardiovascular, hemorrhagic reperfusion injury myocardial infarction

Accurately detecting and quantifying intramyocardial hemorrhage(IMH) is critical for patient management. QSM has evolved into the standard method for iron imaging. However, obtaining cardiac QSM for IMH evaluation is difficult due to well-known technical challenges.  Here, we developed a motion-robust 3D multi-echo GRE technique and combined them with a high-dynamic-range QSM algorithm to derive reliable QSM maps in IMH hearts. We tested and validated it in phantom, ex-vivo, and in-vivo IMH hearts in animal models. We demonstrated that the proposed method could accurately detect IMH and reliably quantify iron concentration with a free-breathing scan under 6 minutes.