Electronic Posters : Cardiovascular Imaging
Click on to view the abstract pdf and click on to view the video presentation.
Myocardial Function: Experimental Models & Human Studies I

Monday May 9th
Exhibition Hall  14:00 - 16:00 Computer 36

14:00 3353.   Quantitative Evaluation of Regional RF shimming on a Wide Aperture Dual-Channel Multi-Transmit 3.0T: Implications for cardiac MRI  
Ramkumar Krishnamurthy1, Amol Pednekar2, Marc Kouwenhoven3, Paul Harvey3, Claudio Arena4, Benjamin Cheong4, and Raja Muthupillai4
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.

14:30 3354.   Quantification of Left Bundle Branch Block on Left Ventricular Regional Wall Motion Using Six-Segment Center Point Trajectory Mapping 
Ting Song1,2, Jeffrey A Stainsby3, Maureen N Hood2,4, and Vincent B Ho2,4
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 Sen1
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.

15:30 3356.   Relative Area Change (RAC) Better Reflects Right Ventricular Ejection Fraction (RVEF) than Longitudinal or Transverse Functional Measurements in Pulmonary Hypertension Patients 
Andrew James Swift1,2, Smitha Rajaram1, David Capener1, Judith Hurdman3, Robin Condliffe3, Charlie Elliot3, David G Kiely3, and Jim M Wild1
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

Tuesday May 10th
  13:30 - 15:30 Computer 36

13:30 3357.   Evaluation of cardiac function using noninvasive phase-contrast MRI, cine MRI and invasive pressure-volume techniques on pigs at rest and under pharmacologic stress test 
Hung-Yu Lin1,2, Darren Freed3, Trevor Lee3, Rakesh Arora3, Ayyaz Ali4, Waiel Almoustadi3, Bo Xiang1, Fei Wang1, Scott B King1, Boguslaw Tomanek1, and Ganghong Tian1
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.

14:00 3358.   Dynamic PVA Gel Phantom for Material Property Assessment Using SPAMM-PAV 
Ziheng Zhang1, Peter B. Brown1, Donald P. Dione2, Albert J. Sinusas2, and Smita Sampath1
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.

14:30 3359.   Comparison of Regional Myocardial Function in the Human and the Mouse 
Christakis Constantinides1, Daniel Rueckert2, and Dimitrios Perperidis1
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.

15:00 3360.   Characterization of iron load in rat myocardium at 7T by R2 map 
Gyula Kotek1, Matteo Milanesi2, Gavin Houston3, Piotr Wielopolski1, Gabriella N. Doeswijk1, Gabriel P. Krestin1, and Monique Bernsen1
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.

Wednesday May 11th
  13:30 - 15:30 Computer 36

13:30 3361.   Assessment of the Right Ventricular Function in Patients with Chronic Obstructive Pulmonary Disease Using MRI 
Yan Gao1, Xianging Du2, Wen Qin2, and Kuncheng Li2
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.

14:00 3362.   Optimization of Whole-Heart Cine MRI with a 128 Channel Receive Coil 
Himanshu Bhat1, Philipp Hoecht1, Sven Zuehlsdorff2, Azma Mareyam3, Boris Keil3, Andreas Potthast4, Melanie Schmitt4, Lawrence L Wald3, Michael Hamm1, and David E Sosnovik3
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.

14:30 3363.   Manual right ventricle segmentation on short-axis SSFP views: quantification of the regional inter-observer variability. 
Laurent BONNEMAINS1,2, Damien MANDRY2,3, Pierre-Yves MARIE3,4, and Pierre-André VUISSOZ2,5
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.

15:00 3364.   Left Ventricular Volumes, Mass and Function normalized to the body surface area, age and gender from CMR in a large cohort of well-treated Thalassemia Major patients without myocardial iron overload. 
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 Pepe1
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.

Thursday May 12th
  13:30 - 15:30 Computer 36

13:30 3365.   Surgical ventricular restoration fails to improve regional left ventricular shape in terms of curvedness 
Liang Zhong1, Yi Su2, Srikanth Sola3, Jose L Navia3, Terrance Chua1, Ghassan Kassab4, and Ru San Tan1
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.

14:00 3366.   Magnetic Resonance Analysis of Right Ventricular Volumetric Function for the Noninvasive Diagnosis of Pulmonary Hypertension 
Amir H Davarpanah1, Parmede Vakil1, Octavia Biris1, Sanjiv Shah2, Timothy Carroll1, and James Carr1
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

14:30 3367.   A preliminary assessment of diastolic dysfunction with normal ejection fraction with cine MRI of the atrioventricular junction motion 
Sohae Chung1, Elodie Breton1, and Leon Axel1
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.

15:00 3368.   Left Ventricular Strain through Radial Tagging: Efficiency and Validity 
Abbas N Moghaddam1,2, Khaled Z. Abd-Elmoniem3, Golanz Heidari1, Stefan Ruehm1, and J. Paul Finn1
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.

Electronic Posters : Cardiovascular Imaging
Click on to view the abstract pdf and click on to view the video presentation.
Myocardial Function: Experimental Models & Human Studies II

Monday May 9th
Exhibition Hall  14:00 - 16:00 Computer 37

14:00 3369.   Displacement-encoded and manganese-enhanced cardiac MRI reveal that nNOS, and not eNOS, plays the dominant role in modulating calcium cycling in the mammalian heart 
Moriel Vandsburger1, Brent A French2, Kramer M Christopher2, Xiaodong Zhong3, and Frederick H Epstein2
1Biological Regulation, Weizmann Institute of Science, Rehovot, Israel, 2University of Virginia, United States, 3Siemens Medical Solutions, United States

Nitric oxide (NO) is generated by both endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS) in the heart, however the role of each in NO signaling is unclear. In this study, we used manganese-enhanced MRI to probe the role of each NOS in modulating L-type calcium channel function, and cine-DENSE MRI to study the role of each NOS in contractile function. Our results indicate that nNOS, and not eNOS, dominates modulation of calcium cycling in vivo.

14:30 3370.   Analysis of segmental myocardial performance in patients after heart transplantation 
Daniela Foell1, Tobias Wengenmayer1, Bernd Andre Jung2, Elfriede Schilli1, Anna Lena Stroh1, Christoph Bode1, Jürgen Hennig2, and Michael Markl2
1Cardiology and Angiology, University Hospital Freiburg, Freiburg, Germany, 2Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Germany

Regional left ventricular motion is altered in transplant rejection. We used MR tissue phase mapping to analyze segmental three-directional myocardial velocities in stable patients after heart transplantation (HTX, n=9) without signs of rejection. Compared to healthy controls (n=20) reduced segmental long-axis velocities in systole and diastole and increased diastolic radial velocities were found. These altered peak velocities might be an expression of remodeling and fibrosis in the transplanted heart. The knowledge of the alterations in regional motion in the transplanted heart under stable conditions is essential in order to use myocardial velocities as diagnostic tools in transplant rejection.

15:00 3371.   Comparison of SNR Efficiencies and Strain for Cine DENSE Images Acquired using Conventional EPI, Flyback EPI and Spiral k-space Trajectories 
Xiaodong Zhong1, Bruce S Spottiswoode2, Craig H Meyer3,4, and Frederick H Epstein3,4
1MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, United States, 2MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, Western Cape, South Africa, 3Radiology Department, University of Virginia, Charlottesville, VA, United States, 4Biomedical Engineering Department, University of Virginia, Charlottesville, VA, United States

Two-dimensional (2D) cine DENSE provides a time series of pixel-wise displacement and strain measurements for the myocardium through the cardiac cycle. Previous cine DENSE studies used fast imaging techniques such as echo-planar (EPI) and spiral for rapid k-space data sampling. In this study, cine DENSE sequences were developed that employed three different k-space trajectories, namely conventional bottom-up interleaved EPI, flyback bottom-up interleaved EPI, and interleaved spiral. SNR efficiency and myocardial strain measured with these three techniques were compared. The three techniques produced similar strain results, although the SNR efficiency of spiral cine DENSE was higher than the other two.

15:30 3372.   Fiber Tracking of the Human Heart In Vivo 
Sonia Nielles-Vallespin1, Choukri Mekkaoui2, Timothy G Reese2, Peter Gatehouse1, Thorsten Feiweier3, Peter Speier3, David E Sosnovik2, and David Firmin1
1Cardiovascular MR Unit, Royal Brompton And Harefield NHS Foundation Trust, London, United Kingdom, 2Martinos Center for Biomedical Imaging, Massachussetts General Hospital, Charlestown, MA, United States, 3Siemens AG Healthcare Sector, Erlangen, Germany

A stack of five 2D slices of the heart was acquired in a healthy volunteer using a diffusion weighted stimulated echo (STEAM) single shot EPI sequence, with a total acquisition time of 40 min. Images were post-processed to create whole heart helix angle fibre tractography maps and fractional anisotropy (FA) maps.

Tuesday May 10th
  13:30 - 15:30 Computer 37

13:30 3373.   Quantification of Left Ventricular Torsion by Off-Resonance Insensitive CSPAMM (ORI-CSPAMM) 
Meral Reyhan1,2, and Daniel B Ennis1,2
1Department of Radiological Sciences, Diagnostic Cardiovascular Imaging Section, University of California, Los Angeles, CA, United States, 2Biomedical Physics Interdepartmental Program, University of California, Los Angeles, CA, United States

The objective of this study was to evaluate the FAST (Fourier Analysis of STimulated echoes) method for quantifying left ventricular (LV) torsion in five healthy volunteers using Off-Resonance Insensitive CSPAMM (ORI-CSPAMM), which adds a 180° RF refocusing pulse in the middle of the motion encoding gradient. There was excellent agreement between SPAMM and ORI-CSPAMM torsion estimates with a bias of -1.5° and 95% CIs(-4.0°, 0.9°). The mean peak systolic torsion was 8.9°±2.1° for ORI-CSPAMM and 7.4°±2.2° for SPAMM. ORI-CSPAMM permits the FAST analysis of LV torsion during systole and diastole and may report more accurate values due to the refocusing.

14:00 3374.   Multichannel RF Transmission Improves Cardiac Cine bSSFP MRI at 3.0T 
Oliver M Weber1, and Javier Sanchez Gonzalez1
1Philips Healthcare, Madrid, Spain

Current cardiac MRI at 3.0 T is hampered by inferior quality of bSSFP cine images. RF transmission with multiple channels (MTx) increases B1 homogeneity and allows for shortening of TR. In six volunteers, cardiac cine bSSFP MRI was performed with and without the use of MTx. With MTx, TRs were reduced by 0.3-0.4 ms, and resulting images provided better signal homogeneity and higher CNR and suffered from fewer artifacts. Usage of MTx thus greatly enhanced image quality and reliability.

14:30 3375.   Time-Evolution of Edema in Reperfused Acute Myocardial Infarction: Implications for Assesment of Area-At-Risk 
Veronica L M Rundell1, Avinash Kali1, Xiangzhi Zhou1, Ying Liu1, Richard L Q Tang1, Andreas Kumar2, and Rohan Dharmakumar1
1Radiology, Northwestern University, Chicago, IL, United States, 2Laval University

T2-weighted MRI of acute myocardial infarction (AMI) has been used to determine Area-At-Risk. To investigate the resolution time of edema following ischemia-reperfusion injury, a canine model of reperfused AMI was investigated using both T2 mapping and T2 STIR protocols before and during infarction and again on days 2, 5, 7 and 56 following reperfusion. The percent volume of hyperintense myocardial regions (edema) peaked on day 2 and 5, respectively on T2-STIR images and T2 maps. Hyperintensity resolved to pre-infarct levels by week 8. Imaging approach and time to imaging may be key factors in determining Area-at-Risk and salvagable myocardium.

15:00 3376.   Age-Related Differences of 3D Blood Flow in the Left Heart 
Daniela Foell1, Steffen Taeger1, Bernd Andre Jung2, and Michael Markl2
1Cardiology and Angiology, University Hospital Freiburg, Freiburg, Germany, 2Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Germany

Whole heart flow-sensitive 4D MRI was performed to analyze the complex blood flow in the left atrium and ventricle in healthy volunteers. The study included healthy subjects (n=22) equally divided in two age-groups to investigate the influence on age of atrial and ventricular flow patterns (existence, extent, and duration of vortex flow). Older individuals demonstrated a tendency towards a lower number, degree, duration, extent and velocity of vortices in the LA. Furthermore they had significantly less pronounced vortices in the base of the LV with lower velocities and a reduced number of vortices in the midventricular parts of the LV.

Wednesday May 11th
  13:30 - 15:30 Computer 37

13:30 3377.   Effects of Autologous Bone Marrow Mononuclear Cells Transplantation through Coronary Artery Bypass Grafting in Patients with Chronic Myocardial Infarction Assessed by Magnetic Resonance Imaging: A Randomized, Double Blind, Placebo-controlled Pilot Trial 
Minjie Lu1, Shihua Zhao1, Shiliang Jiang1, Sheng Liu2, Yan Zhang1, and Zuoxiang He3
1Radiology, Fuwai Hospital, Beijing, Beijing, China, People's Republic of, 2Cardiac Surgery, Fuwai Hospital, Beijing, Beijing, China, People's Republic of, 3Nuclear Medicne, Fuwai Hospital, Beijing, Beijing, China, People's Republic of

Recent studies have shown that autologous bone marrow mononuclear cell (aBM-MNC) transplantation can be effectively performed in human beings either by the coronary route or by endoventricular injections. However, scanty data are available for patients undergoing coronary artery bypass grafting (CABG).Accordingly, the aim of this study was to use an ¡°one-stop¡± non-invasive imaging examination-MRI to evaluate the feasibility and safety of aBM-MNC transplantation in patients with chronic myocardial infarction(MI) undergoing CABG.

14:00 3378.   Single-Breathhold Three-Dimensional Cardiac Cine MRI with Retrospective Cardiac Gating using High Acceleration kat ARC (k- & adaptive t- Autocalibrating Reconstruction for Cartesian Sampling) 
Peng Lai1, Marcus T Alley2, Shreyas S Vasanawala2, and Anja C.S Brau1
1Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States, 2Radiology, Stanford University, Stanford, CA, United States

Quantitative assessment of cardiac function requires 3D cardiac cine MRI with retrospective gating. Recently developed kt methods have shown potential for highly accelerated cine MRI. However, limited work has been done to address retrospective gating, especially with 3D cine imaging. This work develops a kat ARC-based fast dynamic imaging method for retrospectively-gated 3D cine MRI. Based on our evaluations on 4 volunteers, the proposed method can achieve 8x acceleration using 8-channel cardiac coils and provide high-quality motion depiction of the entire ventricle in a single breathhold.

14:30 3379.   The effect of through plane motion on left ventricular regional rotation: a study using slice-following harmonic phase (SF-HARP) imaging. 
David Brotman1, Ziheng Zhang2, and Smita Sampath2
1Fairfield University, Fairfield, CT, United States, 2Yale University

Recent studies reveal that regional rotation may be primarily responsible for the creation of suction enabling normal diastolic filling, and may serve as an early diagnostic indicator of diastolic dysfunction. Here, we highlight the importance of taking into account through-plane motion when calculating regional rotation. We employ a combination of slice-following tagged MRI and harmonic phase tracking (SF-HARP) to compute true two dimensional trajectories of myocardial material points, from which rotation is computed. Our results (rotation curves, and rotation-circumferential shortening loops) show differences in the computed rotation values in comparison to conventional tagging. In conclusion, SF-HARP provides reliable and accurate quantification of regional rotation in the left ventricle.

15:00 3380.   Pancreatic Exocrine Function and Cardiac Iron in Patients with Iron Overload and with Thalassemia 
Jin Yamamura1, Regine Grosse2, Andrea Jarisch3, Gritta E. Janka4, Peter Nielsen5, Gerhard Adam1, and Roland Fischer5,6
1Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany, 2Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, 3Stem Cell Transplant Center, Johann Wolfgang Goethe-University of Frankfurt, Frankfurt, Germany, 4Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, 5Department of Biochemistry and Molecular Biology II: Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, 6Children’s Hospital & Research Center Oakland, Oakland, California, United States

In patients with iron overload, assessment of cardiac iron by fast MRI-R2/R2* methods has become a standard of care. We measured R2* relaxation rates in the myocardium by MRI in comparison with the exocrine pancreatic function by means of serum pancreatic enzyme determination in patients with ß-thalassemia.Patients at risk of elevated cardiac iron levels could be identified by the exocrine pancreatic lipase and amylase function parameters.

Thursday May 12th
  13:30 - 15:30 Computer 37

13:30 3381.   Optimal tag distance for myocardial MR motion analysis of healthy and diseased mice 
Bastiaan J van Nierop1, Tom J & L Schreurs1,2, Hans C van Assen2, Gustav J Strijkers1, and Klaas Nicolay1
1Biomedical NMR, department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, 2Biomedical Image Analysis, department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands

Tagged cinematographic MRI using SPAtial Modulation of Magnetization (SPAMM) enables assessment of myocardial tissue displacement in vivo. However, a poorly chosen tag distance may result in inaccurate estimations of displacement. Only a few studies address the question, which tag distance results in the most accurate estimation of displacement. Therefore, this study aimed to determine the optimal SPAMM tag distance to accurately calculate tissue displacement in the mouse left ventricle, using optical flow analysis. It was concluded that the most accurate estimations for in vivo murine myocardial displacements are obtained with tag distances between 1.0 and 1.5 mm, both in healthy and hypertrophied hearts.

14:00 3382.   Diagnostic Capability and Reproducibility of Myocardial Strain Measured by DENSE MRI in Patients with Acute Myocardial Infarction 
Kakuya Kitagawa1, Hideki Miyagi1, Shingo Kato1, Yeonyee Elizabeth Yoon1, Motonori Nagata1, Shinichi Takase1, Andreas Sigfridsson2, and Hajime Sakuma1
1Radiology, Mie University Hospital, Tsu, Mie, Japan, 2Center for Medical Image Science and Visualization, Linköping University, Linköping, Sweden

We assessed the hypothesis that myocardial strain measured by DENSE MRI can accurately diagnose the extent of LV myocardial injury in patients with AMI. Myocardial strains were quantified by DENSE MRI and custom made software in 20 patients with AMI treated with primary PCI, and were compared with LGE-MRI. Myocardial strains were significantly reduced in segments with transmural infarction compared with those without. The LV global strain showed a good correlation with LV infarct size. Myocardial strains by DENSE MRI showed high intra- and inter-observer reproduciblity. DENSE MRI may be highly useful for monitoring functional recovery of LV myocardium.

14:30 3383.   Free Breathing 3D Imaging of Right Ventricular Structure and Function using Respiratory and Cardiac Self-Gated Cine MRI 
Yanchun Zhu1,2, Jing Liu2, Pascal Spincemaille2, Thanh D. Nguyen2, Minisha Kochar3, Debbie W Chen3, Jonathan Lessick3, Shanglian Bao1, Liuquan Cheng4, Martin R Prince2, Yi Wang2, and Jonathan W Weinsaft3
1Beijing Key Lab of Medical Physics and Engineering, Peking University, Beijing, Beijing, China, People's Republic of, 2Cornell Cardiovascular Magnetic Resonance Imaging Laboratory, Radiology Department,Weill Cornell Medical College, New York, NY, United States, 3Department of Medicine, Weill Cornell Medical College, New York, NY, United States, 4Department of Radiology, Chinese PLA General Hospital, Beijing, China, People's Republic of

Free breathing 3D imaging of right ventricular structure and function using respiratory and cardiac self-gated cine MRI compare with traditional 2D SSFP cine MRI. The purpose of this study is to test the utility of 3D SSFP for RV quantification. 2D and 3D cine MRI were performed in random order on seven normal volunteers. RV chamber volumes were measured by manual planimetry at end-diastole and end systole and used for calculation of RV ejection fraction. These data demonstrate that free breathing 3D cine MRI can comprehensively assess RV structure and function. Future study is necessary to augment temporal resolution of 3D cine MRI and test performance for RV assessment in routine clinical practice.

15:00 3384.   Use of oxygen challenge to assess myocardial oxygenation: A potential tool to image oxygen metabolism. 
Marzena M Wylezinska1, Jordi L Tremoleda1, Joseph Habib2, Daniel Stuckey2, and Willy Gsell1
1Biological Imaging Centre, Imaging Sciences Department, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom, 2National Heart and Lung Institute, Imperial College London, London, United Kingdom

Aerobic metabolism is a vital and fundamental mechanism of attaining energy in mammals. Due to the diversity of organic substrates involved, the rate of aerobic metabolism can only be directly measured through the oxygen consumption. However, current non-invasive quantitative techniques (15O-PET, 17O-MRI) have been limited by both their expense and complexity. We propose a novel technique in which BOLD-dependent changes in T2* were measured in conjunction with saturating arterial blood with oxygen to extract the effects of the reduction of oxy-haemoglobin. Myocardial T2* was observed to increase by 15% thus offering a robust quantitative index of aerobic metabolism.

Electronic Posters : Cardiovascular Imaging
Click on to view the abstract pdf and click on to view the video presentation.
Myocardial Tissue Characterization: Human Studies

Monday May 9th
Exhibition Hall  14:00 - 16:00 Computer 38

14:00 3385.   Assessment of the gray zone: a comparison of two quantitative methods in heart failure patients 
Tobias Voigt1, Peter Koken1, Simon G. Duckett2, Anoop K. Shetty2, Christian Stehning1, Aldo Rinaldi2, Reza Razavi2, Tobias Schaeffter2, and Andrea J. Wiethoff3
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.

14:30 3386.   Improved detection of papillary muscle infarction by high-resolution 3D free breathing delayed enhancement CMR 
Thanh D Nguyen1, Jason Chinitz2, Minisha Kochar2, Debbie Chen3, Parag Goyal2, Helina Kassahun2, Martin R Prince1, Yi Wang1, and Jonathan W Weinsaft2
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.

15:00 3387.   Non-selective double inversion recovery pre-pulse for flow-independent black blood myocardial scar imaging: optimization of the T1 suppression range 
Sarah Anne Peel1, Geraint Morton1, Eike Nagel1, and René M Botnar1
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.

15:30 3388.   Three-segment Center Point Trajectory Model for Segmental Motion Tracking of Myocardial Infarction 
Ting Song1,2, Jeffrey A Stainsby3, Maureen N Hood2,4, and Vincent B Ho2,4
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.

Tuesday May 10th
  13:30 - 15:30 Computer 38

13:30 3389.   Scar-coronary cardiac MR imaging acquired by navigator-gated 3D fat-suppressed delayed-enhancement imaging technique 
Yasuo Amano1, Tomonari Kiriyama1, Yoshio Matsumura1, Masaki Tachi1, Tetsuro Sekine1, and Shinichiro Kumita1
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.

14:00 3390.   Variations in Myocardial T1 with Cardiac Cycle at 1.5T 
Xiaopeng Zhou1,2, Melanie S Kotys3, Christian Stehning4, Stefan E Fischer3, Scott D Flamm1, and Randolph M Setser1
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.

14:30 3391.   Myocardial T1 measurement: comparison of modified Look-Locker inversion recovery (MOLLI) and TI scout 
Yuan Chang Liu1, Chia-Ying Liu1, Rob J van der Geest2, Joao Lima3, David Bluemke4, and Collen Hadigan5
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.

15:00 3392.   Imaging of the Right Ventricular Wall at 3T in suspected ARVD: Black-blood Proton density and T1-w imaging both with and without fat-saturation compared with multi-echo Dixon technique 
Caroline Daly1, Tosin Osuntokun1, Mark Knox1, Deirdre Ward1, Ross Murphy1, Ruth Dunne1, Peter Beddy1, James F Meaney1, Gerard Boyle1,2, Matthew Clemence3, and Andrew J Fagan1,2
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.

Wednesday May 11th
  13:30 - 15:30 Computer 38

13:30 3393.   Myocardial T1 and T2 measurement in patients with cardiac amyloid and comparison with normal controls 
James Glockner1
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.

14:00 3394.   MultiContrast Delayed Enhancement (MCODE) Improves Interpretation of Cardiac MRI Delayed Enhancement: A Clinical Validation Study 
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 Arai1
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.

14:30 3395.   Myocardial T2 mapping with respiratory navigator and non-rigid registration: comparison of motion compensation techniques 
Shivraman Giri1, Saurabh Shah2, Hui Xue3, Jens Guehring3, Sven Zuehlsdorff2, Yiu-Cho Chung2, Subha V. Raman1, and Orlando P. Simonetti1
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.

15:00 3396.   Preliminary Investigation of the use of Multi-transmit for Myocardial T2 and T2* Quantification in Normal Volunteers at 3T 
Hua Guo1,2, Ed X. Wu3,4, Wenchuan Wu1,2, Xiangyang Ma5, Guangzhi Wang1,2, and Chun Yuan2,6
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.

Thursday May 12th
  13:30 - 16:00 Computer 38

13:30 3397.   Distribution of Cardiac Iron measured by MRI-R2* 
Jin Yamamura1, Regine Grosse2, Joachim Graessner3, Gritta Janka2, Gerhard Adam1, and Roland Fischer4,5
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.

14:00 3398.   Characterization of the Failing Human Heart via Diffusion Tensor Imaging: an Ex-Vivo Study 
Osama M Abdullah1,2, Stavros G. Drakos3, Divya Ratan Verma3, Josef Stehlik3, Abdallah G Kfoury3, Craig H Selzman3, Craig Myrick4, Greg Russel4, Dean Y. Li3, and Edward W Hsu1
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.

14:30 3399.   Myocardial Fat Deposition In Dilated Cardiomyopathy_Assessment by Using MR Water-Fat Separation Imaging 
Minjie Lu1, Shihua Zhao1, Shiliang Jiang1, Yang Zhang1, Jing An2, Jerecic Renate3, and Saurabh Shah4
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.

Electronic Posters : Cardiovascular Imaging
Click on to view the abstract pdf and click on to view the video presentation.
Experimental Myocardial Imaging & Flow Imaging

Monday May 9th
Exhibition Hall  14:00 - 16:00 Computer 39

14:00 3400.   MR diffusion tensor investigation of transmural heterogeneity of myocardium structural remodeling in postinfarct porcine model 
Yin Wu1,2, and Ed X. Wu2,3
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.

14:30 3401.   Impact of b-value on DTI indices of left ventricular porcine myocardium: a preliminary study 
Yin Wu1,2, Chao Zou1,2, Lijuan Zhang1,2, Wei Liu1,2, Rui-Bin Dai1,2, Na Zhang1,2, and Xin Liu1,2
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.

15:00 3402.   The Tractographic Propagation Angle: A Novel Tool to Detect Infarction and Characterize Myocardial Microstructure 
Choukri Mekkaoui1, Shuning Huang1, Guangping Dai1, Timothy G Reese1, Udo Hoffmann2, Marcel P Jackowski3, and David Sosnovik4
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.

15:30 3403.   A Comparison of Delayed Contrast Enhanced and T1rho MRI for Assessment of LV Remodeling 
Gerald Zsido1, Walter RT Witschey2, Kevin Koomalsingh1, Joseph H Gorman1, Robin Hinmon1, James J Pilla1, Ravinder Reddy3, Maxim Zaitsev2, and Robert Gorman1
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, T1lower case Greek rho 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,.

Tuesday May 10th
  13:30 - 15:30 Computer 39

13:30 3404.   Rapid relative pressure map computation from velocity-encoded phase-contrast measurements 
Gerard R. Crelier1,2, David Brunner2, Sebastian Kozerke2, and Peter Boesiger2
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.

14:00 3405.   Quantification of Vessel-Encoded Arterial Spin Labeling Dynamic Angiography with Auto-Calibration 
Thomas William Okell1, Michael Andrew Chappell1,2, Ursula G Schulz3, and Peter Jezzard1
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.

14:30 3406.   Off-pump Left Ventricular Apical to Descending Aortic Conduits in Adults with Aortic Stenosis: Postoperative Cardiodynamic Evaluation with Cardiac MRI 
Stephanie Clement-Guinaudeau1, Adrian Lam2, Stuart N Hurst1, Robert L Eisner1, Muralidhar Padala1, Vinod H Thourani1, and John N Oshinski1,2
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.

15:00 3407.   Assessment of Myocardial Twist motion by Velocity Encoded MRI in LA - Orientation 
Anja Lutz1, Axel Bornstedt1, Patrick Etyngier2, Robert Manzke3, Wolfgang Rottbauer1, G Ulrich Nienhaus4, and Volker Rasche1
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.

Wednesday May 11th
  13:30 - 15:30 Computer 39

13:30 3408.   Serial assessment of hyperintense post-infarct myocardial edema in mice by T2-weighted MRI 
Ronald J Beyers1, R. Scott Smith1, Yaqin Xu1, Brent A French1, and Frederick H Epstein1
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.

14:00 3409.   Imaging of inflammation using VSOP at multiple time points in a mouse model of myocardial infarction 
Andrea Protti1, Xuebin Dong1, Marcelo Andia2, Sanjay Chaubey1, Bin Yu1, Matthias Taupitz3, Rene Botnar2, and Ajay M Shah1
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.

14:30 3410.   Dual Manganese- and Delayed-Enhanced MRI Detects Myocardial Border Zone Viability in a Murine Myocardial Injury Model 
Ildiko Toma1, Michael Qian2, Jaehoon Chung1, Yongquan Gong3, Rajesh Dash1, Robert C Robbins4, Philip Harnish5, and Phillip C Yang1
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.

15:00 3411.   Implications of 2D slice profile deformations for rapid myocardial T1/T2 quantification using DESPOT 
Matthias Alexander Dieringer1,2, Michael Deimling2,3, Davide Santoro2, Flavio Carinci2,4, Jeanette Schulz-Menger1,2, and Thoralf Niendorf1,2
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.

Thursday May 12th
  13:30 - 15:30 Computer 39

13:30 3412.   Normal distribution on blood flow helicity in the healthy aorta 
Ramona Lorenz1, Jelena Bock1, Jan Gerrit Korvink2,3, and Michael Markl1
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.

14:00 3413.   In-vivo validation of 5-point PC-VIPR for hemodynamic assessment of the hepatic and splanchnic hemodynamics in swine 
Alex Frydrychowicz1, Emily Winslow2, Dan Consigny1, Eric Niespodzany1, Eric Bultman1, Alejandro Roldán-Alzate1, Kevin M Johnson3, Oliver Wieben4, and Scott B Reeder1
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.

14:30 3414.   Whole Heart 4D Hemodynamics in Patients with Transposition of the Great Arteries after Switch Procedure 
Julia Geiger1, Raoul Arnold2, Zoltan Csatari1, Mathias Langer1, and Michael Markl1
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.

15:00 3415.   Analysis of Complex Cardiovascular Flow with Three Component Acceleration Encoded MRI 
Alex J Barker1, Felix Staehle1, Jelena Bock1, Bernd A Jung1, and Michael Markl1
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.