Electronic Posters: Cardiovascular

Tuesday 13:30-15:30 Computer 29

13:30 3572. Measuring the Myocardial Angular Information Through the Radial Tagging

Abbas Nasiraei Moghaddam¹, J. Paul Finn<sup>1

1</sup>Radiology, UCLA, Los Angeles, CA, United States

The angular information of the left ventricle, including the twist, shear and circumferential strain, are of fundamental importance to quantify the regional or global myocardial function . Radial tagging facilitates the measurement of this information . In particular when the density of radial taglines are sufficiently high, it was theoretically shown that the circumferential strain can be measured directly from the K-Space data . In this study we present the application of the circumferential encoding method on the actual cardiac MR images which are tightly tagged in the radial direction using our newly developed sequence. We also show the transmural differences in rotational motion of the left ventricle using these images.

14:00 3573. High Spatio-Temporal Fidelity Nongated Cardiac MRI with a 3 Second Patient-Adaptive Scan

Behzad Sharif¹, John Andrew Derbyshire², Yoram Bresler<sup>1

1</sup>Electrical and Computer Engineering, Coordinated Science Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, United States; ²Translational Medicine Branch, NHLBI, National Institutes of Health, Bethesda, MD, United States

Patient-Adaptive Reconstruction and Acquisition Dynamic Imaging with Sensitivity Encoding (PARADISE), is a highly accelerated non-gated dynamic imaging scheme that enables artifact-free imaging while providing performance guarantees on achievable SNR and spatio-temporal resolution. In addition to parallel imaging, the method gains acceleration from a sparse physiologically-driven spectral support model (in x-y-f space); hence it is doubly accelerated and adaptive. In this work, we present a modification of the PARADISE method that enables high spatio-temporal fidelity nongated 2D cine imaging with short scan times (3 seconds per slice). The method uses prospective adjustments to the x-y-f-space support to accommodate short scan times.

14:30 3574. Prolonged Right Ventricular Post-Systolic Isovolumic Period in Pulmonary Arterial Hypertension: A Reflection of Diastolic Dysfunction?

Gert Jan Mauritz¹, J. Tim Marcus¹, Nico Westerhof¹, Pieter E. Postmus¹, Anton Vonk Noordegraaf<sup>1

1</sup>VU University Medical Center, Amsterdam, Netherlands

In PAH a prolonged time interval between pulmonary valve closure and tricuspid valve opening is observed. This period is assumed to measure a prolonged right ventricular (RV) relaxation, and to reflect diastolic dysfunction. In this study it was shown that this period is the consequence of a prolonged contraction of the RV free wall which continues after pulmonary valve closure causing a post-systolic contraction. In contrast the RV isovolumic relaxation period is not increased. Therefore, in clinical practice the isovolumic period between pulmonary valve closure and tricuspid valve opening is not a real measure of diastolic dysfunction in PAH patients.

15:00 3575. The Impact of Myosin Heavy Chain Isoforms on Contractile Behavior of the Heart

Yong Chen^1,2, Julian E. Stelzer³, Xin Yu<sup>1,2

1</sup>Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States; ²Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, United States; ³Department of Physiology and Biophysics, Case Western Reserve University

In the present study, we evaluated the impact of shift in myosin heavy chain (MHC) isoforms on in vivo ventricular function in thyroid-deficient rats. Our results show that increased expression of β-MHC not only reduced the magnitude of peak systolic strain and torsion, but also altered the timing when the myocardium reached peak systole, leading to deteriorated cardiac function in hypothyroid rat hearts.

Wednesday 13:30-15:30 Computer 29

13:30 3576. Increased Left Ventricular Torsion in Hypertrophic Cardiomyopathy Mutation Carriers with Normal Wall Thickness

Iris Rüssel¹, Wessel Brouwer¹, Tjeerd Germans¹, Paul Knaapen¹, J Tim Marcus¹, Jolanda van der Velden¹, Marco Götte¹, Albert van Rossum<sup>1

1</sup>VU University Medical Center, Amsterdam, Netherlands

Hypertrophic cardiomyopathy (HCM) is caused by mutations in mainly sarcomeric genes. Increased left ventricular (LV) torsion has been observed in patients with manifest hypertrophy, but abnormalities in myocardial contractility might already be present in HCM mutation carriers with normal wall thickness. Therefore, LV torsion and endocardial circumferential strain were studied in HCM mutation carriers using MRI tagging. Increased LV torsion and torsion to endocardial circumferential strain-ratio were found in carriers with respect to controls. The observed difference might be due to HCM-related endocardial myocardial dysfunction.

14:00 3577. Reconstruction of Line Tagged Cardiac Images by Compressed Sensing Algorithm Using Contourlet Transform from Appropriate K-Space Sampling

Sung-Min Gho¹, Narae Choi¹, Dong-Hyun Kim<sup>1,2

1</sup>Electrical and Electronic Engineering, Yonsei University, Shinchon-Dong, Seoul, Korea, Republic of; ²Radiology, Yonsei University, Shinchon-Dong, Seoul, Korea, Republic of

RF tagging in cardiac imaging can be used to analyze the heart wall motion. There is always a push towards higher spatial and/or temporal resolution to enable more accurate quantification. This work is on combining line tagged cardiac imaging with the compressed sensing (CS) algorithm and exploiting the distinct k-space feature of tagged images.

14:30 3578. Characterization of Vortex Flow in the Left Ventricle by Phase Contrast Magnetic Resonance Imaging

Samuel Ting¹, Paaladinesh Thavendiranathan¹, Helene Houle², Gianni Pedrizzetti³, Subha V. Raman¹, Mani Vannan¹, Orlando Simonetti<sup>1

1</sup>The Ohio State University, Columbus, OH, United States; ²Siemens Medical Solutions, Mountain View, CA, United States; ³University of Trieste, Trieste, Italy

Characterization of vortex formation and flow within the heart may be used as tool for diagnosing and understanding pathophysiological conditions of the heart. We present preliminary results demonstrating that phase contrast magnetic resonance imaging may be used to quantitatively evaluate and characterize formation of vortices within blood flow in the left ventricle of the heart.

15:00 3579. Quantitative Assessment of Atrioventricular Plane Displacement in Normals and Diastolic Heart Failure-A Cine MRI Study.

Reena Anand¹, Sohae Chung¹, Sharath Bhagavatula, Leon Axel<sup>1

1</sup>Radiology, NYU Langone Medical Center, New York, NY, United States

In conventional cine MRI, it is observed that the atrioventricular (AV) plane of the heart descends towards the apex during systole and moves back towards the atrium during the diastole. The displacement of the AV plane through the cardiac cycle is an expression of the systolic and diastolic performance of the heart, so that it can be used to detect early diastolic dysfunction. In this study, we have investigated the potential of MRI measurement of left AV plane displacement as a means to assess diastolic dysfunction.

Thursday 13:30-15:30 Computer 29

13:30 3580. Combination of Through-Plane Tissue Phase Mapping and SPAMM for 3D Cardiac Motion Assessment

Anja Lutz¹, Axel Bornstedt¹, Robert Manzke², Gerd Ulrich Nienhaus³, Volker Rasche<sup>1

1</sup>University Hospital of Ulm, Ulm, BW, Germany; ²Philips Research Europe, Hamburg; ³Institute of Technology, University of Karlsruhe, Germany

Cardiac motion assessment can be performed by tagged imaging combined with HARP analysis and with tissue phase mapping (TPM). The tagging approach enables fast assessment of the in-plane motion component, where TPM can be applied for full assessment of the motion vector in 3D but requires at least fourfold measurement time. In this contribution tagging is combined with TPM for 3D + time motion assessment. There is no information loss of the through plane motion, when tag lines are applied. The combination can be used to reduce imaging time for motion encoding in 3D.

14:00 3581. MRI Compatible Treadmill

Eric L. Foster¹, Mihaela Jekic^1,2, Jacob A. Bender^1,2, John W. Arnold³, Subha V. Raman^1,4, Orlando P. Simonetti<sup>1,5

1</sup>Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States; ²Biomedical Engineering, The Ohio State University; ³Agricultural Technical Institute, The Ohio State University; ⁴Internal Medicine, The Ohio State University; ⁵Internal Medicine and Radiology, The Ohio State University

Treadmill exercise testing in conjunction with MRI may offer improved diagnosis of heart disease compared to current modalities; however, traditional treadmills can not operate safely within the MR environment. An MR compatible treadmill was developed using hydraulic drive and elevation systems and fiber-optic data transmission, allowing the treadmill to be positioned immediately adjacent to the MR examination table. The treadmill successfully passed MR safety and compatibility tests. Six healthy volunteers were exercised to peak cardiovascular stress and transferred to the MR table. Real time cine imaging was completed within 38±6.4 s, meeting the AHA guideline of imaging within 60 s.

14:30 3582. Early Diastolic Strain-Velocity Temporal Relationship Assessment Using SPAMM-PAVE

Ziheng Zhang¹, Donald P. Dione¹, Peter B. Brown¹, Erik M. Shapiro¹, Chengqing Wu², Robert Todd Constable¹, Albert J. Sinusas¹, Smita Sampath<sup>1

1</sup>Yale University School of Medicine, New Haven, CT, United States; ²Yale University School of Public Health, New Haven, CT, United States

A novel MR imaging technique, spatial modulation of magnetization with polarity alternated velocity encoding (SPAMM-PAVE), is presented to investigate the left ventricular early diastolic strain-velocity relationships. This technique provides simultaneous measurements of 1-D myocardial displacement and chamber blood velocity with a high temporal resolution of 14 ms, sensitive to early diastolic events undetectable by current state-of-the-art methods. The reliability of the measurement is demonstrated by an intra-subject study of a normal volunteer. The interplay of regional volumetric changes in the left ventricle in response to filling patterns is investigated through comparing the regional strain and blood inflow velocity curves in 8 normal volunteer studies.

15:00 3583. 4CH TX/RX Surface Coil for 7T: Design, Optimization and Application for Cardiac Function Imaging

Matthias Alexander Dieringer^1,2, Wolfgang Renz, ^1,3, Tomasz Lindel, ^1,4, Frank Seifert, ^1,4, Tobias Frauenrath¹, Helmar Waiczies, ^1,4, Florian von Knobelsdorff-Brenkhoff⁵, Davide Santoro¹, Werner Hoffmann⁴, Bernd Ittermann, ^1,4, Jeanette Schulz-Menger^2,5, Thoralf Niendorf<sup>1,2

1</sup>Berlin Ultrahigh Field Facility, Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany; ²Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Humboldt-University, Berlin, Germany; ³Siemens Healthcare, Erlangen, Germany; ⁴Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany; ⁵CMR-Unit Charité Campus Buch, Berlin, Germany

Practical impediments of ultra high field cardiovascular MR (CVMR) can be catalogued in exacerbated magnetic field and radio frequency (RF) inhomogeneities, susceptibility and off-resonance effects, conductive and dielectric effects in tissue, and RF power deposition constraints, which all bear the potential to spoil the benefit of CVMR at 7T. Therefore, a four element cardiac transceive surface coil array was developed. Cardiac imaging provided clinically acceptable signal homogeneity with an excellent blood myocardium contrast. Subtle anatomic structures, such as pericardium, mitral and tricuspid valves and their apparatus, papillary muscles, and trabecles were accurately delineated.

Myocardial Function: Experimental & Human Studies II

Hall B Monday 14:00-16:00 Computer 30

14:00 3584. Left Ventricular Dyssynchrony: Effect of Age, Ejection Fraction, Mass and Cardiovascular Disease

Daniela Foell¹, Bernd Jung², Elfriede Schilli³, Felix Staehle², Christoph Bode³, Michael Markl<sup>2

1</sup>Cardiology , University Hospital , Freiburg, Germany; ²Diagnostic Radiology, Medical Physics, University Hospital, Freiburg, Germany; ³Cardiology, University Hospital, Freiburg, Germany

MR tissue phase mapping (TPM) was employed to study the relationships of age, heart rate, left ventricular (LV) ejection fraction (EF), and LV-mass with myocardial dyssynchrony among 95 subjects with normal and pathological cardiac function. Compared to age-matched controls significantly (p<0.01) enhanced myocardial dyssynchrony was found in patients with hypertensive heart disease (n=18) and dilated cardiomyopathy (n=12) with most prominent changes if left bundle branch block was present (n=7). Multiple regressions revealed significant relationships of dyssynchrony with LV-EF, LV-mass, and age. As sensitive markers for LV dysfunction, both radial systolic and long-axis diastolic dyssynchrony were superior to systolic long-axis dyssynchrony.

14:30 3585. MR Assessment of Left Ventricular Strain After Repair of Tetralogy of Fallot

Karen G. Ordovas¹, Marcus Carlsson², Elyse Foster³, Alison Meadows⁴, Alastair Martin⁴, Michael Hope⁴, Loi Do⁴, Charles Higgins⁴, Maythem Saeed<sup>4

1</sup>Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States; ²Clinical Physiology, Lund University, Lund, Sweden; ³Cariology, UCSF, San Francisco, CA, United States; ⁴Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States

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15:00 3586. Assessment of Cardiac Function and Infarct Size Following Myocardial Infarction in Mitochondrial Cyclophilin-D Knockout Mice

Anthony N. Price¹, Shiang Y. Lim², Johannes Riegler¹, Derek M. Yellon², Derek J. Hausenloy², Mark F. Lythgoe<sup>1

1</sup>Centre for Advanced Biomedical Imaging, Department of Medicine and UCL Institute of Child Health, University College London, London, United Kingdom; ²The Hatter Cardiovascular Institute, University College London Hospital and Medical School, London, United Kingdom

Coronary heart disease (CHD) remains one of the leading causes of morbidity and mortality worldwide. A principal symptom of CHD is myocardial infarction (MI), which leads to a complex process of ventricular remodelling and ultimately heart failure. Novel treatment strategies which are capable of limiting myocardial infarct size, preventing LV remodelling and preserving cardiac function are needed to improve clinical outcomes. The inhibition of mitochondrial cyclophilin-D (CypD), has been reported to reduce infarct size in pre-clinical studies. Here we present the first MRI assessment of cardiac function and infarct size in CypD^-/- mice at 48 hours following myocardial infarction.

15:30 3587. Healthy Ageing in Females Is Associated with Altered Cardiac Energetics Related to Both Systolic and Diastolic Function: A Comparison of MRS, Cardiac Tagging and Cine Imaging

Kieren Grant Hollingsworth¹, David Emerys Jones², Julia Lindsay Newton³, Bernard D. Keavney⁴, Guy A. MacGowan⁵, Andrew Mark Blamire<sup>1

1</sup>Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom; ²Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom; ³Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom; ⁴Institute of Human Genetics, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom; ⁵Cardiology, Freeman Hospital, Newcastle upon Tyne, Tyne and Wear, United Kingdom

It is unclear whether there are relationships between cardiac energetics and age-related decline of systolic and diastolic function. 25 healthy females with no previous history of cardiac disease were recruited, covering the age range 18-65. Phosphorus spectroscopy, cine imaging and cardiac tagging were carried out. PCr/ATP ratio was found to decline significantly with age, most strongly in the over 60 group. E/A ratio, peak circumferential strain and torsion recoil rates declined with age, with the first two significantly associated with the PCr/ATP ratio. This suggests that both systolic and diastolic function are associated with energetic changes in ageing.

Tuesday 13:30-15:30 Computer 30

13:30 3588. γ-Sarcoglycan Deficiency Reduces Cardiac Function and T2 in Old Mice

Sean Charles Forbes¹, Sean Germain², Nathan Bryant³, Glenn A. Walter<sup>3

1</sup>Department of Physical Therapy, University of Florida, Gainesville, FL, United States; ²Department of Pediatrics, University of Florida, United States; ³Department of Physiology and Functional Genomics, University of Florida, United States

Limb Girdle muscular dystrophy Type 2C is characterized by a deficiency in γ-sarcoglycan, a protein associated with the dystrophin-glycoprotein complex on the cell membrane. In this study, the effects of a lack of γ-sarcoglycan (Sgsg-/-) and dystrophin (mdx) on cardiac function and myocardium T2 in old mice were examined. The findings indicate that Sgsg-/- and mdx have a reduced left ventricular ejection fraction compared to age-matched controls, with no differences in Sgsg-/- and mdx. Also, a shorter T2 was observed in the myocardium of Sgsg-/- compared to controls, suggesting an increased prevalence of fibrosis in Sgsg-/-.

14:00 3589. Development and Validation of 3 Tesla Functional Cardiac Magnetic Resonance Imaging in Preterm and Term Newborns

Alan Groves¹, Gaia Chiesa², Giuliana Durighel², Stephen Goldring², Julie Fitzpatrick², Sergio Uribe³, Reza Razavi⁴, Jo Hajnal², A David Edwards<sup>2

1</sup>Institute of Clinical Sciences, Imperial College , London, United Kingdom; ²Institute of Clinical Sciences, Imperial College, London, United Kingdom; ³Division of Imaging Sciences, King's College , London, United Kingdom; ⁴Division of Imaging Sciences, King's College, London, United Kingdom

The ability to reliably monitor and support the circulation in preterm and term newborns may have a key role in optimising outcome in this population. Cardiac magnetic resonance (CMR) imaging has the potential to significantly advance understanding of cardiac function in sick preterm and term infants. In this work we describe optimisation of cine and phase contrast CMR imaging in newborn infants; assess repeatability of CMR methods and compare this to existing echocardiographic methods; and describe preliminary normative values for cardiac output and systemic flow volume in stable preterm and term infants.

14:30 3590. The Effect of K-Space Trajectory on Strain-Encoded Cardiac MRI

Elsayed H. Ibrahim¹, Wolfgang Rehwald², Sven Zuehlsdorff², Richard D. White<sup>1

1</sup>University of Florida, College of Medicine, Jacksonville, FL, United States; ²Siemens AG Healthcare Sector, Cardiovscular MR R&D, Chicago, IL, United States

Strain encoding (SENC) is a newly-developed MRI technique for measuring myocardial strain in the through-plane direction. It requires simple post-processing and gives resolution on the pixel level. With conventional SENC sequence, two separate scans are required to obtain the strain images. Such approach increases scan time and could result in image misregistration in post-processing. Non-Cartesian k-space trajectories are becoming more popular because they allow for large undersampling with acceptable image quality. In this work, SENC was combined with radial k-space acquisition using interleaved SENC tunings and radial undersampling. Scan time was reduced to one breath-hold with comparable image quality.

15:00 3591. High Resolution, Functional Real-Time Cardiac MR Imaging Using a Combination of Compressed Sensing and Parallel Imaging

Tobias Wech¹, Marcel Gutberlet¹, Daniel Stäb¹, Dietbert Hahn¹, Herbert Köstler<sup>1

1</sup>Institute of Radiology, University of Wuerzburg, Wuerzburg, Bavaria, Germany

To achieve a sufficient temporal and spatial resolution in functional cardiac MRI, real time acquisition has to be accelerated by a factor of 8 – 10 compared to Fourier MRI. In this work, a combination of compressed sensing and parallel imaging has been implemented, tested in a simulation using undersampled data of a segmented cine acquisition and finally applied to in-vivo data sampled in real time. The reconstructions for the real time acquisition and for the simulated data result in high resolution images with an excellent SNR and do not show any visible artefacts.