Ramkumar Krishnamurthy¹, Amol Pednekar², Marc Kouwenhoven³, Paul Harvey³, Claudio Arena⁴, Benjamin Cheong⁴, and Raja Muthupillai^4
1Bioengineering, Rice University, Houston, Texas, United States, ²Philips Healthcare, Houston, Texas, United States, ³Philips Healthcare, Best, Netherlands, ⁴Diagnostic and Interventional Radiology, St. Luke's Episcopal Hospital, Houston, Texas, United States

In this prospective study we quantitatively evaluated the performance of a regional RF shimming approach that exploits the ability to independently modulate the amplitudes and phases of two RF transmit channels at 3.0T for cardiovascular MR applications. The results from this study of 11 subjects show that: (a) greater than 20% variations in flip angle exist even in as small a region as the heart and can cause substantial shading artifact; (b) RF shimming using a multi-channel RF transmit system is feasible, and quantitative metrics show a robust improvement in B1 homogeneity across the region of interest.

Ting Song^1,2, Jeffrey A Stainsby³, Maureen N Hood^2,4, and Vincent B Ho^2,4
1Global Applied Science Laboratory, GE Healthcare, Bethesda, MD, United States, ²Radiology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States, ³Global Applied Science Laboratory, GE Healthcare, Toronto, ON, Canada, ⁴Radiology, National Naval Medical Center, Bethesda, MD, United States

Left Bundle Branch Block (or LBBB) is a common cardiac electrical conduction abnormality. It is important to quantify the degree of LBBB using cardiac MR. We propose a six-segment center point trajectory (CPT) approach for LBBB quantification. The proposed method was implemented on a total of nine healthy and LBBB subjects. A quantitative metric generated by CPT showed statistically significant distinction between normal and LBBB regions.

Surya C Gnyawali¹, Sashwati Roy¹, Jaideep Banerjee¹, Savita Khanna¹, and Chandan K Sen^1
1Surgery, Ohio State University, Columbus, OH, United States

MiRNAs are capable of post-transcriptional gene regulation by binding to their target messenger RNAs (mRNAs), leading to mRNA degradation or suppression of translation. MiRNAs have recently been shown to play pivotal roles in cardiovascular biology. Dicer, a RNAse III endonuclease, plays a key role in processing of miRNA into their functional mature form. A number of recent reports point towards a central role of miRNA in cardiac development and function. We have developed cardiomyocyte-specific conditional dicer knockout mice. Dicer knockout of adult mice resulted in a overt phenotype featuring ventricular enlargement, myocyte hypertrophy, and heart failure. In the current study we sought to functionally characterize the dicer deficient adult murine heart.

Andrew James Swift^1,2, Smitha Rajaram¹, David Capener¹, Judith Hurdman³, Robin Condliffe³, Charlie Elliot³, David G Kiely³, and Jim M Wild^1
1Academic Unit of Radiology, Sheffield, South Yorkshire, United Kingdom, ²NIHR Cardiovascular Biomedical Research Unit, Sheffield, United Kingdom, ³Pulmonary Vascular Disease Unit, Royal Hallamshire Hospital, Sheffield, United Kingdom

This study in patients with pulmonary hypertension (PH) assesses the relation of RAC, transverse and longitudinal RV measurements with RVEF as calculated from multislice cine MRI. RVEF is better reflected by RAC than longitudinal wall motion or transverse wall motion in patients with PH. We postulate this is because RAC assesses RV function in both the transverse and longitudinal directions. Transverse RV function showed a similar correlation to longitudinal function for predicting RVEF in our mixed cohort of PH patients

Hung-Yu Lin^1,2, Darren Freed³, Trevor Lee³, Rakesh Arora³, Ayyaz Ali⁴, Waiel Almoustadi³, Bo Xiang¹, Fei Wang¹, Scott B King¹, Boguslaw Tomanek¹, and Ganghong Tian^1
1Institute for Biodiagnostics, National Research Council Canada, Winnipeg, Manitoba, Cambodia, ²Radiology, University of Manitoba, Winnipeg, Manitoba, Canada, ³Cardiac Sciences Program, St. Boniface Hospital, Winnipeg, Manitoba, Canada, ⁴Cardiothoracic Surgery, Papworth Hospital, Cambridge, United Kingdom

This study is to validate noninvasive cardiac output measurement techniques of phase-contrast MRI and cine MRI using an invasive pressure-volume loops analysis on a swine model at rest and under pharmacologic stress conditions.

Ziheng Zhang¹, Peter B. Brown¹, Donald P. Dione², Albert J. Sinusas², and Smita Sampath^1
1Department of Diagnositc Radiology, Yale University, School of Medicine, New Haven, CT, United States, ²Section of Cardiovascular Medicine, Yale University, School of Medicine, New Haven, CT, United States

Our goal is to evaluate the future application of the SPAMM-PAV (Spatial Modulation of Magnetization with Polarity Alternated Velocity encoding) technique for regional quantification of myocardial material properties through a series of dynamic phantom experiments. We examine the sensitivity to detect edge responses in strain due to sharp changes in material properties, and the sensitivity to detect changes in Young’s modulus of elasticity (Ecc) in gel phantoms with varying stiffness. Results demonstrate 1) using a MICSR reconstruction, we are able to achieve desired strain response, and 2) using SPAMM-PAV combined with a thick-shell constitutive model, we can reliably detect differences in Ecc.

Christakis Constantinides¹, Daniel Rueckert², and Dimitrios Perperidis^1
1Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus, ²Imperial College London, London, United Kingdom

This work quantifies and compares regional and global cardiac performance in humans and mice. Such effort attempts to provide evidence to validate the hypothesis of functional scaling from mouse to human. Its potential clinical significance is in mouse phenotyping for determining myocardial dysfunction, in correlation with perfusion and metabolism.

Gyula Kotek¹, Matteo Milanesi², Gavin Houston³, Piotr Wielopolski¹, Gabriella N. Doeswijk¹, Gabriel P. Krestin¹, and Monique Bernsen^1
1Radiology, Erasmus MC, Rotterdam, Netherlands, ²Agilent Technologies UK Ltd, Netherlands, ³General Electric Healthcare, Netherlands

R2 and R2* mapping techniques have been used to index iron overload either from endogenous sources (e.g. myocardial infarct) or to track exogenously injected cells labeled with paramagnetic iron oxide [ref]. The advantages of high field imaging, namely improved SNR and sensitivity to iron load, are offset by the considerable challenges of rodent cardiac imaging at 7T such as increased macroscopic field inhomogeneities and short R-R intervals (~180ms). In this work we assess the robustness of R2 measurement in healthy & infarcted myocardium, as well as in the presence of SPIO labeled cells.

Yan Gao¹, Xianging Du², Wen Qin², and Kuncheng Li^2
1Department of Radiology, Xuanwu Hospital of Capital Medical University, Beijing, Beijing, China, People's Republic of, ²Department of Radiology, Xuanwu Hospital of Capital Medical University, Beijing, China, People's Republic of

We studied right ventricular function in 46 patients with mild to severe chronic obstructive pulmonary disease (COPD) determined by the pulmonary function test (PFT) using MRI. Our study population consisted of 30 control subjects. The RVEF was significantly lower in severe COPD group than in other groups (p < 0.01). The correlation was excellent between the MRI results and forced expiratory volume in 1 sec (r = 0.859 for RVEF, r= -0.839 for RV MM) in COPD patients. The RVEF and RV MM measured by MRI correlate well with the severity of disease as determined by PFT in COPD patients.

Himanshu Bhat¹, Philipp Hoecht¹, Sven Zuehlsdorff², Azma Mareyam³, Boris Keil³, Andreas Potthast⁴, Melanie Schmitt⁴, Lawrence L Wald³, Michael Hamm¹, and David E Sosnovik^3
1Siemens Medical Solutions USA Inc., Charlestown, MA, United States, ²Siemens Medical Solutions USA Inc., Chicago, IL, United States, ³Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States, ⁴Siemens Healthcare, Erlangen, Germany

We have previously reported the development of a prototype 128 channel receive coil and MR system for cardiac MR at 3T. Here we describe further optimization of the system and its supported sequences, in particular balanced SSFP. We demonstrate the feasibility of high quality 2D multi-slice whole-heart cine imaging with acceleration factors of upto 6 in a single breath-hold using the 128 channel receive coil.

Laurent BONNEMAINS^1,2, Damien MANDRY^2,3, Pierre-Yves MARIE^3,4, and Pierre-André VUISSOZ^2,5
1Cardiologie Infantile, CHU Nancy, NANCY, France, ²IADI, Nancy University, NANCY, France, ³Médecine Nucléaire, CHU Nancy, NANCY, France, ⁴CIC801, INSERM, NANCY, France, ⁵U947, INSERM, NANCY, France

Short-axis cine-MRI sequences have become the gold standard for Right Ventricle (RV) function assessment. This process requires a manual segmentation of RV endocardium with known low reproducibility. In a mixed sample of 90 normal, dilated or hypertrophic RV, we analysed the regional variations of manual segmentation between two experienced observers with different metrics and found that the infundibular and tricuspid regions were each responsible for an average of 35 to 40% of the variability in volumes assessment. The variation in the choice of end-diastolic and end-systolic phases was frequent but caused non-significant volumetric variations.

Antonella Meloni¹, Maria Chiara Dell'Amico¹, Brunella Favilli¹, Giovanni Donato Aquaro¹, Pierluigi Festa¹, Elisabetta Chiodi², Stefania Renne³, Gennaro Restaino⁴, Vincenzo Positano¹, Maria Concetta Galati⁵, Massimo Lombardi¹, and Alessia Pepe^1
1Fondazione G.Monasterio CNR-Regione Toscana and Institute of Clinical Physiology, Pisa, Italy, ²Arcispedale “S. Anna”, Ferrara, Italy, ³P.O. “Giovanni Paolo II”, Lamezia Terme, Italy, ⁴Università Cattolica del Sacro Cuore, Campobasso, Italy, ⁵A.O. "Pugliese-Ciaccio", Catanzaro, Italy

Cardiovascular Magnetic Resonance allows an accurate and reproducible quantification of left ventricular (LV) parameters. In Thalassemia major (TM) patients different “normal” LV values have been reported. In this study, the ranges for normal LV volumes, mass and ejection fraction normalized to the influence of body surface area (BSA), age and sex were established using the data of a large cohort of well-treated TM patients without myocardial iron overload.

Liang Zhong¹, Yi Su², Srikanth Sola³, Jose L Navia³, Terrance Chua¹, Ghassan Kassab⁴, and Ru San Tan^1
1National Heart Centre, Singapore, Singapore, ²Institute of High Performance Computing, A*STAR, Singapore, ³Cleveland Clinic, USA, ⁴Indiana University-Purdue University, Indiananpolis, USA

Adverse left ventricular (LV) remodeling begins with infarct expansion post-myocardial infarction (MI) and is followed by progressive cardiac fibrosis and impaired contractility of the remaining cardiomyocytes. Surgical ventricular restoration (SVR) has been used to treat ventricular aneurysms and that results in good patient’s outcomes. However, recent STICH trial reported that adding SVR to coronary bypass CABG was not associated with a greater improvement in reduced intermediate mortality. It is believed that LV dilation and distortion occurs post-SVR operation, which may contribute to worsening heart failure. This study was hence to examine the regional LV shape pre- and post SVR.

Amir H Davarpanah¹, Parmede Vakil¹, Octavia Biris¹, Sanjiv Shah², Timothy Carroll¹, and James Carr^1
1Cardiovascular Imaging, Northwestern University, Chicago, IL, United States, ²Cardiology, Northwestern University, Chicago, IL

RV volumetric parameters of decompensation are useful for differentiating patients with PH and can be used to noninvasively detect pulmonary hypertension

Sohae Chung¹, Elodie Breton¹, and Leon Axel^1
1Radiology Department, NYU Langone Medical Center, New York, NY, United States

While systolic cardiac function is commonly assessed with the simple global measure of ejection fraction, many patients with clinical symptoms of heart failure have normal ejection fraction, indicating that they are primarily suffering from diastolic dysfunction. In this study, the motion of the atrioventricular junction was measured by using the conventional cardiac cine MRI to assess abnormalities in motion of the LV during different phases of diastole. We performed a retrospective study of 11 patients and compared them with two control groups, 13 healthy young subjects and 5 healthy older subjects.

Abbas N Moghaddam^1,2, Khaled Z. Abd-Elmoniem³, Golanz Heidari¹, Stefan Ruehm¹, and J. Paul Finn^1
1David Geffen School of Medicine, UCLA, Los Angeles, CA, United States, ²Biomedical Engineering, Polytechnique University, Tehran, Iran, ³National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States

Assessment of local contractility of the left ventricle complements global functional parameters such as cardiac output and ejection fraction. The local contraction of the LV is quantifiable by its circumferential strain. We have shown that radial tagging facilitates the extraction of this parameter directly from the k-Space data if the density of the radial taglines is sufficiently high . In this study, we present our initial findings on the performance of this approach and validity of the results.

Tobias Voigt¹, Peter Koken¹, Simon G. Duckett², Anoop K. Shetty², Christian Stehning¹, Aldo Rinaldi², Reza Razavi², Tobias Schaeffter², and Andrea J. Wiethoff^3
1Philips Research Laboratories, Hamburg, Germany, ²Kings College London, London, United Kingdom, ³Philips Healthcare, Best, Netherlands

In this study gray zone imaging using quantitative T1 mapping sequences was investigated. Two different sequences were compared with respect to gray zone characterization using spin density and T1 values. A standard Look Locker T1 mapping sequence was compared with a modified Look Locker (MOLLI) sequence including cardiac motion correction. Motion corrected MOLLI results showed improved delineation of the myocardial border and a better basis for the determination of the gray zone extent based on a clustering of spin density and T1.

Thanh D Nguyen¹, Jason Chinitz², Minisha Kochar², Debbie Chen³, Parag Goyal², Helina Kassahun², Martin R Prince¹, Yi Wang¹, and Jonathan W Weinsaft^2
1Radiology, Weill Cornell Medical College, New York, NY, United States, ²Medicine/Cardiology, Weill Cornell Medical College, New York, NY, United States, ³Cornell University, Ithaca, NY, United States

Papillary muscle infarction (PMI) is a serious consequence of acute myocardial infarction (AMI). The objective of this study was to prospectively compare free-breathing navigator 3D with breath-held 2D delayed enhancement cardiac MR for PMI detection in a cohort of patients presenting with AMI. 25% (n=27) had PMI as determined by either 2D or 3D imaging. Navigator 3D imaging was found to provide improved detection of PMI compared to breath-held 2D imaging.

Sarah Anne Peel¹, Geraint Morton¹, Eike Nagel¹, and René M Botnar^1
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, London, United Kingdom

MRI late gadolinium enhancement using the inversion recovery sequence is the current gold standard for the assessment of myocardial viability. Although it achieves high contrast between infarct and normal myocardium, there is often poor infarct-to-blood contrast. In this work we show that the non-selective double inversion recovery pre-pulse can be used to suppress blood signal and improve depiction of sub-endocardial infarcts. Adjustment of the T1 suppression range allows the user to control the level of blood suppression. In patient studies, the time post contrast administration appears to have a smaller effect on signal characteristics than the T1 suppression range.

Ting Song^1,2, Jeffrey A Stainsby³, Maureen N Hood^2,4, and Vincent B Ho^2,4
1Global Applied Science Laboratory, GE Healthcare, Bethesda, MD, United States, ²Radiology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States, ³Global Applied Science Laboratory, GE Healthcare, Toronto, ON, Canada, ⁴Radiology, National Naval Medical Center, Bethesda, MD, United States

The vascular territory commonly characterizes clinically ischemic heart disease. We describe an automated and quantitative approach for the evaluation of discrete myocardial wall motion in terms of vascular territory (i.e. LAD, RCA, and LCX), using a novel wall motion characterization method called regional center point trajectory algorithm. The three-segment center point model enables separate analysis and quantification of coronary artery disease by their respective vascular territories, thereby allowing segmental tracking and quantification of wall motion.

Yasuo Amano¹, Tomonari Kiriyama¹, Yoshio Matsumura¹, Masaki Tachi¹, Tetsuro Sekine¹, and Shinichiro Kumita^1
1Nippon Medical School, Tokyo, Japan

Scar-coronary imaging was obtained using a single navigator-gated 3D fat-suppressed delayed-enhancement MR imaging sequence. Compared to the standard 2D delayed-enhancement imaging, the scar-coronary imaging depicted the myocardial scar sufficiently with good CNR. The patent proximal coronary arteries were visualized well by this imaging. Scar-coronary cardiac MR imaging using a single navigator-gated 3D fat-suppressed delayed-enhancement MR imaging study was feasible for visualization of the myocardial scar and patent proximal coronary arteries.

Xiaopeng Zhou^1,2, Melanie S Kotys³, Christian Stehning⁴, Stefan E Fischer³, Scott D Flamm¹, and Randolph M Setser^1
1Imaging Institute, Cleveland Clinic, Cleveland, OH, United States, ²Cleveland State University, Cleveland, OH, United States, ³Philips Healthcare, OH, United States,⁴Philips Research, Hamburg, Germany

Healthy volunteers (n=5) were imaged at 1.5T to determine whether myocardial T1 varies throughout the cardiac cycle. T1 mapping was performed using MOLLI at 2 left ventricular short axis levels at end-systole, mid-diastole and end-diastole. T1 variation between time points was smaller than 8%, which demonstrates that cyclic variation of T1 is negligible at 1.5T. In addition, no regional variation in T1 was seen. The myocardial T1 values are of particular importance for the diagnosis of myocardial diseases, which warrants further study of cyclic myocardial T1 changes at higher magnetic field strengths.

Yuan Chang Liu¹, Chia-Ying Liu¹, Rob J van der Geest², Joao Lima³, David Bluemke⁴, and Collen Hadigan^5
1Department of Radiology, Johns Hopkins Hospital, Baltimore, MD, United States, ²Department of Radiology, Leiden University Medical Center, Netherlands, ³Johns Hopkins Hospital, ⁴Radiology and Imaging Sciences, National Institutes of Health (NIH), ⁵National Institute of Allergy and Infectious Diseases (NIAID), NIH

Different cardiac MR acquisition sequences have been used to obtain myocardial T1 values. Among which available techniques, MOdified Look-Locker Inversion-recovery (MOLLI) and inversion-recovery TrueFisp (TI scout) sequences are widely used in research and clinical settings. We compared myocardial T1 values derived from both MOLLI and TI scout techniques in the post gadolinium delayed enhancement experiments.

Caroline Daly¹, Tosin Osuntokun¹, Mark Knox¹, Deirdre Ward¹, Ross Murphy¹, Ruth Dunne¹, Peter Beddy¹, James F Meaney¹, Gerard Boyle^1,2, Matthew Clemence³, and Andrew J Fagan^1,2
1Centre for Advanced Medical Imaging, St. James's Hospital / Trinity College, Dublin, Ireland, ²School of Medicine, Trinity College University of Dublin, Ireland, ³Philips Healthcare, Reigate, United Kingdom

Diagnosis of fibrofatty infiltration of the myocardium, a cardinal feature of Arrhythmogenic Right Ventricular Dysplasia (ARVD) until the advent of cardiac MR could only be diagnosed by myocardial biopsy or at autopsy. Cardiac Magnetic Resonance offers comprehensive depiction of the anatomy and function of the right ventricle, and because of he characteristic appearance of fat on MR images allows depiction of fat within the wall. Our aim was to investigate the feasibility of multi-echo Dixon technique for water fat separation during cardiac imaging at 3T compared to the standard approach of black-blood spin-echo imaging with and without fat suppression.

James Glockner^1
1Radiology, Mayo Clinic, Rochester, MN, United States

Myocardial tissue relaxation measurements have been suggested as a potential alternative technique to post-contrast late gadolinium enhancement imaging for identification of patients with cardiac amyloid. This has the advantage of avoiding gadolinium administration in patients who may have reduced renal function. Septal myocardial T1 and T2 measurements were performed in 14 patients with cardiac amyloid diagnosed by positive echocardiography and contrast-enhanced MRI and compared with values measured in a group of normal controls. No significant difference in myocardial relaxation times was identified, suggesting that tissue relaxation measurements alone are unlikely to confidently diagnose cardiac involvement in pateints with systemic amyloidosis.

W Patricia Bandettini¹, Peter Kellman¹, Christine Mancini¹, Oscar Julian Booker¹, Sujethra Vasu¹, Steve W Leung¹, Joel R Wilson¹, Pamela Vincent¹, Sujata M Shanbhag¹, Marcus Y Chen¹, and Andrew Ernest Arai^1
1National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States

Multicontrast delayed enhancement (MCODE) is a technique that has been useful in discriminating subendocardial myocardial infarction from blood pool by simultaneously providing a T2-weighted image in addition to the standard late gadolinium enhancement (LGE) T1 image, thus allowing distinction between true enhanced myocardium and blood pool. Our clinical validation study demonstrates that in over one-third of cases of abnormal LGE and cases of questionable LGE, the T2 data acquired using GRE-MCODE adds diagnostic value to the final interpretation above that obtained in a LGE T1 image alone.

Shivraman Giri¹, Saurabh Shah², Hui Xue³, Jens Guehring³, Sven Zuehlsdorff², Yiu-Cho Chung², Subha V. Raman¹, and Orlando P. Simonetti^1
1The Ohio State University, Columbus, OH, United States, ²Siemens Healthcare, Chicago, IL, United States, ³Siemens Corporate Research, Princeton, NJ, United States

In this work, we propose a myocardial T2 mapping sequence with two motion-compensation schemes: respiratory navigator and non-rigid registration. Their combined application provides complementary motion-compensation, with navigator providing reproducible positioning of the heart in all directions, and registration correcting for any residual in-plane motion. Results show a significant reduction in motion-induced T2 variability in myocardial T2 maps. The proposed sequence permits reliable T2 mapping without subject breath-hold and may enable 3D T2 maps of the myocardium in future.

Hua Guo^1,2, Ed X. Wu^3,4, Wenchuan Wu^1,2, Xiangyang Ma⁵, Guangzhi Wang^1,2, and Chun Yuan^2,6
1Biomedical Engineering Department, Tsinghua University, Beijing, Beijing, China, People's Republic of, ²Center for Biomedical Imaging Research, Tsinghua University, Beijing, Beijing, China, People's Republic of, ³Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, Hong Kong, ⁴4Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, Hong Kong, ⁵Philips Research Asia, Shanghai, China, People's Republic of, ⁶Department of Radiology, University of Washington, Seattle, WA, United States

Increased B0 and B1 inhomogeneity, together with increased motion artifacts, present challenges for cardiac imaging and quantification at 3T. Although breathhold acquisition method can improve the reproducibility of T2* and T2 measurement, the B1 nonuniformity may deteriorate their accuracy and confound the final diagnosis for monitor iron overload in patients with thalassaemia major. This study measured myocardial T2* and T2 in normal subjects at 3T with multi-transmit technology using single-breathhold acquisitions. The preliminary results demonstrated the effectiveness of the multi-transmit technique for myocardial T2* and T2 quantification improvement at 3T.

Jin Yamamura¹, Regine Grosse², Joachim Graessner³, Gritta Janka², Gerhard Adam¹, and Roland Fischer^4,5
1Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany, ²Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, ³Siemens AG, Hamburg, Germany, ⁴Department of Biochemistry and Molecular Biology II: Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany, ⁵Children’s Hospital & Research Center Oakland, Oakland, California, United States

Iron overload in the heart is the leading cause of death for thalassemia patients receiving chronic blood transfusions. The measurement of the septal R2* (= 1/T2*) in a mid-papillary short axis slice can be used for artifact-free cardiac iron measurements. The purpose of this study was to identify the variation of the transverse relaxation rate R2* in a left ventricular mid-papillary cardiac slice and to find out the most appropriate site to measure the cardiac iron with the least artifacts and boundary effects. The measurement of MRI-R2* in the interventricular septum is the least affected method by boundary effects to detect patients with iron overload at risk of developing heart failure.

Osama M Abdullah^1,2, Stavros G. Drakos³, Divya Ratan Verma³, Josef Stehlik³, Abdallah G Kfoury³, Craig H Selzman³, Craig Myrick⁴, Greg Russel⁴, Dean Y. Li³, and Edward W Hsu^1
1Bioengineering, University of Utah, Salt Lake City, UT, United States, ²Small Animal Core Research, University of Utah, Salt Lake City, UT, United States, ³UTAH Cardiac Transplant Program, University of Utah & Intermountain Medical Center, Salt Lake City, UT, United States, ⁴Intermountain Donor Services, Salt Lake City, UT, United States

Diffusion tensor imaging was used to characterize heart specimens from normal donors and chronic heart failure, which via histology is known to include increased interstitial fibrosis, cardiomyocyte hypertrophy, and reduced microvascular density. Results show that failing hearts have decreased fractional anisotropy, but increased mean, longitudinal, and axial diffusivities. These findings are consistent with the histopathology and demonstrate a potential role for DTI in characterizing the failing human heart.

Minjie Lu¹, Shihua Zhao¹, Shiliang Jiang¹, Yang Zhang¹, Jing An², Jerecic Renate³, and Saurabh Shah^4
1Radiology, Fuwai Hospital, Beijing, Beijing, China, People's Republic of, ²Siemens Mindit Magnetic Resonance, Siemens Healthcare, MR Collaboration NE Asia., Beijing, China, People's Republic of, ³Siemens Limited China, Siemens Healthcare, MR Collaboration NE Asia, Beijing, Germany, ⁴Siemens Healthcare, Chicago, IL, United States

Fat deposition has a high prevalence in arrhythmogenic right ventricular cardiomyopathy(ARVC). The incidence was reported approximately 68% in ARVC. While it is unclear in dilated cardiomyopathy. In this study, we use the latest water fat separation sequence to evaluate fat deposition in dilated cardiomyopathy(DCM) and found that fat deposition is quite common in DCM and it is associated with DCM characteristics including fibrosis volume and left ventricular function.

Yin Wu^1,2, and Ed X. Wu^2,3
1Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Shenzhen, Guangdong, China, People's Republic of, ²Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong, ³Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong

Previous DTI studies of infarcted heart predominantly focused on the overall myocardial diffusion changes within a certain region. In this study, transmural heterogeneity of myocardium structural remodeling was examined in postinfarct porcine model. Significant reduction of mean apparent diffusion coefficient, axial and radial diffusivities was found to occur earlier around endocardium, indicating that myocardium structural remodeling is transmurally heterogeneous and the endocardium is more vulnerable to infarct injury. The experimental findings suggest the necessity of examining transmural variation of myocardium structural remodeling, and demonstrate DTI is a sensitive tool to reveal the subtle change of tissue structure at cellular level.

Yin Wu^1,2, Chao Zou^1,2, Lijuan Zhang^1,2, Wei Liu^1,2, Rui-Bin Dai^1,2, Na Zhang^1,2, and Xin Liu^1,2
1Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Shenzhen, Guangdong, China, People's Republic of, ²Key Laboratory of Biomedical Informatics and Health Engineering, Chinese Academy of Sciences, Shenzhen, Guangdong, China, People's Republic of

Conventional DTI assumes a free Gaussian process of water diffusion, which may not apply in tissues with complex structures. In this study, effect of b-values on myocardium DTI indices (FA, mean diffusivity, axial and radial diffusivities) was assessed and two fitting models for DWI data were evaluated on LV myocardium. DTI indices substantially decreased with increasing b values. Stat model demonstrated a better fitting for the DWI signals than Monoexp model. This study confirmed the conspicuous influence of b-value on DTI indices quantification, and demonstrated the necessity of optimizing b-value and DWI fitting model for better characterizing the myocardium microstructure.

Choukri Mekkaoui¹, Shuning Huang¹, Guangping Dai¹, Timothy G Reese¹, Udo Hoffmann², Marcel P Jackowski³, and David Sosnovik^4
1Radiology, Harvard Medical School, Massachusetts General Hospital, Martinos Center For Biomedical Imaging, Charlestown, MA, United States, ²Radiology, Massachusetts General Hospital, Harvard Medical School, United States, ³Computer Science, University of São Paulo, Institute of Mathematics and Statistics, São Paulo, Brazil,⁴Cardiology, Harvard Medical School, Massachusetts General Hospital, Martinos Center For Biomedical Imaging, Charlestown, MA, United States

The normal angle between adjacent eigenvectors along myofiber tracts remains unknown. We term this angle the tractographic propagation angle (PA). Consequently, the correct upper limit or threshold angle to use in tractographic reconstructions of the myocardium remains unknown. Here we characterize the propagation angle (PA) in vivoin normal and ex vivo in infarcted hearts. We show that PA is homogenous and low (2-4 degrees) in normal myocardium. In infarcted myocardium, PA rises dramatically and has the potential to facilitate the robust detection of myocardial infarcts.

Gerald Zsido¹, Walter RT Witschey², Kevin Koomalsingh¹, Joseph H Gorman¹, Robin Hinmon¹, James J Pilla¹, Ravinder Reddy³, Maxim Zaitsev², and Robert Gorman^1
1Cardiothoracic Surgery, University of Pennsylvania, Philadelphia, PA, United States, ²Medical Physics, University Medical Center Freiburg, Freiburg i. Breisgau, Baden Württemburg, Germany, ³Radiology, University of Pennsylvania, Philadelphia, PA, United States

Cardiac output progressively deteriorates following myocardial infarction on account of left ventricular myocardial infarction. Recently, a method for spin locked MRI was shown to overcome low frequency mechanisms of nuclear relaxation, enhancing relaxation and improving contrast compared to conventional T2-weighted imaging of MI. In this study, T1 MRI was performed in a swine model of MI to measure mean relaxation times in the myocardium, borderzone, several animals and compared to delayed contrast enhanced (DCE) MRI in a septum based model of MI,.

Gerard R. Crelier^1,2, David Brunner², Sebastian Kozerke², and Peter Boesiger^2
1GyroTools LLC, Winterthur, Switzerland, ²Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland

Intravascular relative pressure maps can be calculated from velocity vector fields as obtained with velocity-encoded phase-contrast MR imaging. An efficient iterative solver for the pressure Poisson equation in arbitrary shaped computational domains is presented.

Thomas William Okell¹, Michael Andrew Chappell^1,2, Ursula G Schulz³, and Peter Jezzard^1
1FMRIB Centre, Department of Clinical Neurosciences, University of Oxford, Oxford, Oxfordshire, United Kingdom, ²Institute of Biomedical Engineering, University of Oxford, Oxford, Oxfordshire, United Kingdom, ³Stroke Prevention Research Unit, Department of Clinical Neurosciences, University of Oxford, Oxford, Oxfordshire, United Kingdom

A theoretical framework for the quantification of vessel-encoded arterial spin labeling dynamic angiography is presented and illustrated by application in a healthy volunteer and patient with vertebral stenosis. The calibration factor that relates the measured signal to blood volume can be robustly determined using the same data, avoiding the need for separate calibration scans. The derived volume flow rates are consistent with those in the literature and capable of clearly showing the level of collateral flow in patient studies.

Stephanie Clement-Guinaudeau¹, Adrian Lam², Stuart N Hurst¹, Robert L Eisner¹, Muralidhar Padala¹, Vinod H Thourani¹, and John N Oshinski^1,2
1Emory University, Atlanta, GA, United States, ²Georgia Institute of Technology, Atlanta, GA, United States

Off-pump apico-aortic conduit (ACC) is an alternative to aortic valve replacement in patients with calcified aortic root. In 10 patients with ACC, hemodynamic data was collected using phase contrast magnetic resonance (PCMR) imaging. Conduit flow was 68,7+/-13,6% of total cardiac output and flow through the native aortic valve was 31,3+/13,6% of cardiac output. In the descending aorta there was 15,8+/-9,9% of cardiac output that flowed in a reverse upward direction from the conduit and 51,4+/-12,2% of cardiac output was directed caudally below the conduit. ACC surgery results in a change in hemodynamics that can be well studied using PCMR.

Anja Lutz¹, Axel Bornstedt¹, Patrick Etyngier², Robert Manzke³, Wolfgang Rottbauer¹, G Ulrich Nienhaus⁴, and Volker Rasche^1
1University Hospital of Ulm, Ulm, BW, Germany, ²Medisys Research Lab, Philips Healthcare, Sureness, France, ³Philips Research NA, Briarcliff Manor, United States,⁴Karlsruhe Institute of Technology, Karlsruhe, Germany

The rotational motion of the heart is an important parameter for the assessment of cardiac function in patients with cardiac diseases. The aim of this study was to investigate the feasibility of velocity encoded MRI to retrieve the twisting motion of the heart from 6 slices acquired in long axes geometry with equidistant radial spacing. Therefore, a black blood prepared, respiratory navigated, segmented and velocity encoded cardiac triggered gradient echo sequence was used. Maximal myocardial twisting was observed in the lateral wall after approx. 36% of the RR cycle.

Ronald J Beyers¹, R. Scott Smith¹, Yaqin Xu¹, Brent A French¹, and Frederick H Epstein^1
1University of Virginia, Charlottesville, VA, United States

Following myocardial infarction (MI), a need exists to differentiate the acute MI from surrounding salvaged area (SA) that together defines the area at risk (AAR). T2w cardiac MRI (T2w CMR) quantifies edema that delineates the AAR, while late gadolinium-enhanced (LGE) CMR quantifies the MI. Past T2w CMR studies have focused on larger mammals, but not mice. Using mice is now common in cardiovascular studies, including the MI model. Here, we applied T2w CMR in post-MI mice to quantify the AAR, along with LGE CMR to quantify MI, to track the AAR, MI, and SA size relationships for 33 days.

Andrea Protti¹, Xuebin Dong¹, Marcelo Andia², Sanjay Chaubey¹, Bin Yu¹, Matthias Taupitz³, Rene Botnar², and Ajay M Shah^1
1Cardiovascular Division, King’s College London BHF Centre of Excellence, London, UK, United Kingdom, ²Division of Imaging Sciences and Biomedical Engineering, King’s College London BHF Centre of Excellence, London, UK, United Kingdom, ³Department of Radiology, Charite-Universitaetsmedizin, Berlin, Germany

Myocardial infarction (MI) represents an acute injury of the myocardium and triggers the recruitment of monocytes and subsequent accumulation of macrophages at the site of injury. Despite intensive research in this field it is still poorly understood how many and which type of monocytes are involved in the migration into the infarct zone. Non-invasive imaging methods is therefore of great interest for the in-vivo investigation of the inflammatory response post MI. In this work, we investigate VSOP for direct imaging of inflammation in a mouse model of MI. We investigated several time points after MI and with different injection protocols.

Ildiko Toma¹, Michael Qian², Jaehoon Chung¹, Yongquan Gong³, Rajesh Dash¹, Robert C Robbins⁴, Philip Harnish⁵, and Phillip C Yang^1
1Medicine/Cardiovascular Medicine, Stanford University, Stanford, California, United States, ²University of California, Berkeley, Berkeley, California, United States,³Radiology, Stanford University, Stanford, California, United States, ⁴Cardiothoracic Surgery - Adult Cardiac Surgery, Stanford University, Stanford, California, United States, ⁵Eagle Vision Pharmaceutical Corp., United States

Delayed enhancement MRI (DEMRI) identifies non-viable myocardium, but is non-specific and may overestimate nonviable territory. Manganese enhanced MRI (MEMRI) signal identifies manganese in viable cells. We performed dual-contrast myocardial assessment, combining DEMRI and MEMRI in a diabetic murine acute infarct model to characterize border zone viability in vivo. MEMRI demonstrated smaller scar volume and percentage compared to DEMRI. Dual-contrast MEMRI-DEMRI may identify at-risk but viable myocardial cells within transmural DEMRI regions.

Matthias Alexander Dieringer^1,2, Michael Deimling^2,3, Davide Santoro², Flavio Carinci^2,4, Jeanette Schulz-Menger^1,2, and Thoralf Niendorf^1,2
1Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Humboldt-University, Berlin, Germany, ²Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine, Berlin, Germany, ³Siemens Healthcare, Erlangen, Germany, ⁴Department of physics, Insubria University, Como, Italy

3D-DESPOT1/2 have been proposed for rapid and accurate T1 and T2 quantification of the brain. A 2D cardiac application with short repetition times (TR) evokes T1 and flip angle dependent saturation phenomena that deform the slice profile and hence bear the potential to render T1/T2 quantification inaccurate. Although these phenomena are known for several years its impact on T1 and T2 quantification using DESPOT has not been examined yet. This study examines the impact of slice profile deformation on the signal of 2D FLASH and 2D b-SSFP and demonstrates its implications for rapid T1 and T2 quantification using DESPOT1/2.

Ramona Lorenz¹, Jelena Bock¹, Jan Gerrit Korvink^2,3, and Michael Markl^1
1Dept. of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany, ²Dept. of Microsystems Engineering - IMTEK, University of Freiburg, Freiburg, Germany, ³Freiburg Institute of Advanced Studies (FRIAS), University Freiburg, Freiburg, Germany

3D blood flow characteristics in the aorta play an important part in the health of individuals. However, in vivo blood flow patterns are complex and dependent on the individual geometry and shape of the aorta. This study provides a fully quantitative analysis and detailed evaluation of the spatial and temporal distribution of mean and peak mean helicity for 12 healthy subjects and in up to 24 analysis planes equally distributed along the aorta. All 12 healthy subjects showed consistent directions of rotation over the entire aorta with high systolic clockwise helicity and a good inter-individual agreement in the aortic arch.

Alex Frydrychowicz¹, Emily Winslow², Dan Consigny¹, Eric Niespodzany¹, Eric Bultman¹, Alejandro Roldán-Alzate¹, Kevin M Johnson³, Oliver Wieben⁴, and Scott B Reeder^1
1Department of Radiology, University of Wisconsin - Madison, Madison, WI, United States, ²Department of Surgery, University of Wisconsin - Madison, Madison, WI, United States, ³Department of Medical Physics, University of Wisconsin - Madison, Madison, WI, United States, ⁴Departments of Radiology and Medical Physics, University of Wisconsin - Madison, Madison, WI, United States

Hepatic and splanchnic blood flow is of particular interest in liver disease such as cirrhosis and portal hypertension. However, comprehensive assessment of flow and morphology is challenging, especially because of the liver’s dual blood supply and complex anatomy. 4D MR velocity mapping is a promising approach to overcome shortcomings of existing diagnostic approaches. This validation study compared a novel radially undersampled 5-point velocity encoding strategy that provides high-resolution, large volume coverage and increased velocity sensitivity with the de facto standard of reference perivascular ultrasound. Excellent correlation and an acceptable measurement bias was found for both methods.

Julia Geiger¹, Raoul Arnold², Zoltan Csatari¹, Mathias Langer¹, and Michael Markl^1
1Radiology and Medical Physics, University Hospital Freiburg, Freiburg, Germany, ²Pediatric Cardiology, University Hospital Freiburg, Freiburg, Germany

The purpose of this study was to employ whole heart flow-sensitive 4D MRI for the identification and quantification of altered aortic and pulmonary hemodynamics in patients with transposition of the great arteries (d-TGA) after arterial switch procedure. Compared to healthy volunteers, significantly increased peak velocities were observed in the modified pulmonary trunk and arteries located fully anterior to the aorta. A correlation between the surgically altered TP positions with the occurrence of vortex flow indicates the potential of 4D flow analysis to evaluate the impact of changes in vascular geometry on regional hemodynamics.

Alex J Barker¹, Felix Staehle¹, Jelena Bock¹, Bernd A Jung¹, and Michael Markl^1
1Medical Physics, Dept. of Radiology, University Medical Center Freiburg, Freiburg, Germany

The measurement of local blood acceleration provides valuable functional information regarding normal and deranged local flow characteristics (e.g. vortex formation). Acceleration data may be estimated from standard velocity encoded images which, however, suffer from noise amplification when calculating spatiotemporal velocity derivatives. As a result, this paper presents the in-vitro and in-vivo implementation of a gradient-optimized acceleration encoded PC-MRI sequence developed to shorten TE and thus the scan duration, especially when performing 4D scans (3D, time-resolved scans). In addition, a simple contrast mechanism to visualize complex flow events such as boundary layer separation, turbulent reattachment, and vortex formation is discussed.