Joint Annual Meeting ISMRM-ESMRMB 2014 10-16 May 2014 Milan, Italy


CARDIOVASCULAR (13:30-15:30)

3839-3861 Velocity & Flow Quantification
3862-3884 CE & Non-CE MRA
3885-3908 Myocardial Function
3909-3932 Vessel Wall Imaging & Emerging Technologies
3933-3955 Emerging Techniques & Image Processing
3956-3979 Myocardial Tissue Characterization

Velocity & Flow Quantification

Tuesday 13 May 2014
Exhibition Hall  13:30 - 14:30

  Computer #  
3839.   1 Phase-Contrast Cine MR Imaging of Pulmonary Artery to Assess Outcome of Balloon Pulmonary Angioplasty in Patients with Chronic Thromboembolic Pulmonary Hypertension
Yoshiaki Morita1, Naoaki Yamada1, Emi Tateishi1, Kumi Ozaki1, Yoshihiro Sanda1, Suzu Kanzaki1, Akihiro Tsuji2, Shigefumi Fukui2, Takeshi Ogo2, Tetsuya Fukuda1, Masahiro Higashi1, Norifumi Nakanishi2, and Hiroaki Naito1
1Department of Radiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan, 2Division of Cardiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan

Recently, balloon pulmonary angioplasty (BPA) has been performed as a treatment option for chronic thromboembolic pulmonary hypertension (CTEPH) with improvement of clinical status and hemodynamics. In this study, we demonstrated that phase-contrast MR imaging (PC-MRI) enables to quantify the pulmonary hemodynamic improvement after BPA. Especially, the change between before and after BPA of AT/ET (acceleration time to ejection time ratio) measured by PC-MRI has a good correlation with that of mean pulmonary artery pressure, suggesting that AT/ET might offer a modality for the noninvasive and repeatable monitoring after BPA.

3840.   2 Comprehensive Analysis of Total Cavo-Pulmonary Connection Hemodynamics with In Vivo and In Vitro 4D Flow MRI and Computational Fluid Dynamics
Alejandro Roldán-Alzate1, Sylvana García-Rodriguez1, Thomas G Steffens2, Kevin M Johnson3, Oliver Wieben1,3, Petros V Anagnostopoulos2, and Christopher J Francois1
1Radiology, University of Wisconsin, Madison, Wisconsin, United States, 2Surgery, University of Wisconsin, Madison, Wisconsin, United States, 3Medical Physics, University of Wisconsin, Madison, Wisconsin, United States

The purpose of this study was to develop an experimental 4D Flow MRI setup as verification of a CFD TCPC model. 4D Flow MRI was performed in two TCPC subjects. Anatomy was segmented from PC-angiograms and converted to a 3D geometry to fabricate physical models and for CFD analysis. Physical models were connected to a perfusion system and imaged using the in vivo protocol. Results for in vivo and in vitro 4D Flow MRI and CFD show comparable velocities and flow distribution. This study connects CFD and 4D Flow MRI for improved TCPC assessment.

3841.   3 Potential hemodynamic biomarkers of pulmonary arterial hypertension measured with an aid of three-dimensional cine phase contrast MR imaging
Masaki Terada1,2, Yasuo Takehara3, Haruo Isoda4, Tomohiro Uto5, Takashi Kosugi6, Tetsuya Wakayama7, and Marcus Alley8
1Iwata City Hospital, Iwata-shi, Shizuoka, Japan, 2Nagoya University, Graduate School of Medicine, Nagoya, Aichi, Japan, 3Hamamatsu Univ. Hospital, Shizuoka, Japan, 4Nagoya University, Graduate School of Medicine, Aichi, Japan, 5Iwata City Hospital, Shizuoka, Japan, 6R teck, Shizuoka, Japan, 7GE Healthcare, Tokyo, Japan, 8Stanford University, CA, United States

The sWSS and OSI with the aid of 4D Flow were thought to be promising hemodynamic biomarkers for PAH diseases.

4 Beta-Blocker Therapy Alters 3D Wall Shear Stress in the Ascending Aorta of Patients with Bicuspid Aortic Valve
Bradley D Allen1, Pim van Ooij1, Alex J Barker1, Jeremy D Collins1, James C Carr1, S. Chris Malaisrie2, Patrick McCarthy2, Jyothy Puthumana3, Preeti Kansal3, and Michael Markl1,4
1Department of Radiology, Northwestern University, Chicago, IL, United States, 2Division of Surgery - Cardiac Surgery, Northwestern University, Chicago, IL, United States, 3Department of Medicine - Cardiology, Northwestern University, Chicago, IL, United States, 4Department of Biomedical Engineering, Northwestern University, Chicago, IL, United States

Patients with bicuspid aortic valve (BAV) are at increased risk of ascending aorta aneurysm development and wall shear stress (WSS) has been hypothesized to be a driver of vascular remodeling and aneurysm progression. Beta-blockers are the guideline-recommended medical therapy to slow aortic dilation in this patient group. In this study, we calculated 3D WSS in the aorta of BAV patients on or not on beta-blockers. We found a trend toward reduced WSS in patients taking beta-blockers, suggesting that a reduction in WSS may be the mechanism by which beta-blockers effectively slow aortic dilatation.

3843.   5 Models of pulmonary vascular resistance in pulmonary hypertension from pulse wave analysis of MRI measurements in the main pulmonary artery
Angela Lungu1, Jim Wild1, Andy Swift1, David Capener1, David Kiely2, and Rod Hose1
1Cardiovascular Science, University of Sheffield, Sheffield, South Yorkshire, United Kingdom, 2Pulmonary Vascular Disease Unit, University of Sheffield, Sheffield, South Yorkshire, United Kingdom

Pulmonary hypertension (PH) is a disease characterised by increased mean pulmonary arterial pressure measured by invasive right heart catheterisation. Temporally and spatially registered images, from two separate MR sequences (phase contrast and bSSFP) were acquired in patients with suspected PH, and in healthy volunteers. Anatomical and flow measurements were obtained throughout the cardiac cycle. The computed waveforms were combined with mathematical models (based on an electrical impedance analogy and wave reflection quantification) to assess the status of the pulmonary circulation. Our results demonstrate that the proposed method has the potential to non-invasively distinguish between normal and clinically stratified PH groups.

3844.   6 Comparison of in vivo 3D flow characteristics to realistic in vitro models with flexible and rigid vessel wall - permission withheld
Ramona Lorenz1, Michael Markl2, Stephan Berner1, Christoph Müller1, and Bernd Jung1
1Dept. of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany, 2Dept. of Radiology and Biomedical Engineering, Northwestern University, Chicago, Illinois, United States

This study is about an in vitro model set up with realistic in-flow conditions. The in vitro models are one to one replica of a normal aorta and were generated by rapid prototyping. One in vitro model with rigid vessel wall and four in vitro models with different flexibility of the vessel walls were employed for MRI flow experiments. The difference in flexibility grade was obtained by different vessel wall thickness of the same flexible material. In vivo and in vitro flow analysis was performed in eight planes distributed over the aorta for comparison of velocity and flow data.

3845.   7 Normal and Pathologically Altered in vivo 3D Aortic Wall Shear Stress Maps
Pim van Ooij1, Wouter V. Potters2, Aart J. Nederveen2, Bradley D. Allen1, Jeremy Collins1, James Carr1, S. Chris Malaisrie3, Michael Markl1,4, and Alex J. Barker1
1Radiology, Northwestern University, Chicago, IL, United States, 2Radiology, Academic Medical Center, Amsterdam, Netherlands, 3Medicine-Cardiology, Northwestern University, Chicago, IL, United States, 4Biomedical Engineering, Northwestern University, Chicago, IL, United States

In this study, a methodology to create 3D WSS vector maps averaged over multiple subjects in a cohort is presented and demonstrated in three cohorts: 10 patients with aortic dilation, 10 patients with aortic valve stenosis and 10 healthy controls. Significance of the differences between cohorts were illustrated by P-value maps. It was found that 13% of the ascending aorta surface of the dilation map showed significantly lower WSS than the control map, whereas 54% of the ascending aorta surface of the stenosis map showed significantly higher WSS than the control map.

3846.   8 Validation of high temporal resolution spiral phase velocity mapping of coronary artery blood flow against Doppler Flowire
Jennifer Keegan1, Claire E Raphael1, Robin Simpson1, Kim Parker2, Peter Drivas3, Ranil de Silva4, Carlo Di Mario4, Sanjay Prasad3, and David Firmin3,5
1Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom, 2Imperial College, London, United Kingdom,3Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, United Kingdom, 4Cardiology, Royal Brompton Hospital, United Kingdom, 5Imperial College London, United Kingdom

The temporal pattern of coronary flow velocity through the cardiac cycle provides important information about coronary haemodynamics and atherosclerotic disease state. In this study, we compare breath-hold high temporal resolution (19ms) spiral phase velocity mapping of proximal left and right coronary blood flow velocity with invasive gold-standard Doppler Flowire measurements in a small group of patients. As expected, MR velocities are lower than Doppler velocities (by 47% on average) but the temporal flow patterns are similar (R2 = .47 - .91). We conclude that spiral phase velocity mapping has the potential to assess temporal patterns of coronary flow velocity non-invasively.

3847.   9 Impaired venous return due to right ventricular diastolic stiffness in Pulmonary Arterial Hypertension
J. Tim Marcus1, Marielle van de Veerdonk2, Frank Oosterveer3, Rudolf Verdaasdonk1, and Anton Vonk Noordegraaf2
1Physics & Medical Technology, VU University Medical Center, Amsterdam, Netherlands, 2Pulmonology, VU University Medical Center, Netherlands, 3VU University Medical Center, Netherlands

The aim was to explore the association between Vena Cava (VC) backflow and right ventricular (RV) diastolic stiffness in pulmonary arterial hypertension (PAH). In 35 PAH patients, VC flow was measured by MRI velocity quantification, and right heart pressures by catheterization. The VC backflow fraction was related to the right atrium maximal pressure (p<0.00001, r2=0.53), and to RV diastolic stiffness (p<0.00001, r2=0.53). This explains the impact of RV diastolic dysfunction on right atrial pressure and subsequently on the venous return in PAH.

3848.   10 Quantification of 3D Arterial and Portal Venous Blood Flow Distribution in Liver Cirrhosis Patients using 4D Flow MRI
Xi Chen1, Michael Markl1, Julio Garcia Flores1, Susanne Schnell1, Kelly Brooke Jarvis1, James Carr1, Jeremy D. Collins1, and Zoran Stankovic1
1Department of Radiology, Northwestern University, Chicago, Illinois, United States

4D flow MRI provides valuable information on blood flow velocities with full spatial (3D) and temporal (cardiac cycle) coverage, which can be applied to volumetric and functional evaluation of liver hemodynamics in liver cirrhosis patients. This study reveals mean velocities in portal venous and arterial systems of liver tend to be lower for liver cirrhosis patients and appear to be wider distributed. This result is showed by plotting velocity histograms of healthy and pathologic groups with selected parameters based on sensitivity test. Quantitative analysis of liver hemodynamics using flow-sensitive 4D MRI may be a standardized method to complement the diagnosis in liver cirrhosis.

3849.   11 Self-calibrated phase-contrast correction of nonlinear background phase in quantitative cardiac imaging
Ek T Tan1, James F Glockner2, Ana Beatrix Solana3, David W Stanley4, and Christopher J Hardy1
1GE Global Research, Niskayuna, NY, United States, 2Radiology, Mayo Clinic, Rochester, MN, United States, 3GE Global Research, Garching, Munich, Germany, 4GE Healthcare, Rochester, MN, United States

A nonlinear, self-calibrated phase-contrast (SCPC) correction method is proposed, which provides an improved fit of the static nonlinear phase in quantitative cardiac phase-contrast imaging. In addition, the method improves on the static tissue detection, takes into account the quiescent cardiac phase, and has an over-fitting prevention step. Normal subjects were imaged at 1.5T and 3T, with the resulting phase validated using a static phantom. The Qp/Qs ratios of seven patients without cardiac shunt were recorded, demonstrating an improved Qp/Qs ratio with the method.

3850.   12 Importance of high temporal resolution in peak flow velocity quantification by phase-contrast imaging
Yin Wu1,2, Ke Jiang1,2, Yucheng Chen3, Xin Liu1,2, and Yiu-Cho Chung1,2
1Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Key Laboratory for MRI, Shenzhen Institutes of Advanced Technology, Shenzhen, Guangdong, China, 2Key Laboratory of Health Informatics, Chinese Academy of Sciences, Shenzhen, Guangdong, China, 3Cardiology Department, West China Hospital, Sichuan University, Chengdu, Sichuan, China

Phase-contrast (PC) MRI is a promising tool to quantify peak flow velocity which is essential in the diagnosis of valvular diseases. Inconsistency between MR and echo measurements in flow quantification has been reported, and inadequate temporal resolution may be one contributing factor when flow is non-turbulent. In this study, we used an EPI-based PC sequence with a high temporal resolution of ~20ms to quantify peak flow velocity and compared the results with 3 traditional FLASH-based PC techniques. Studies of 6 healthy volunteers showed that the peak velocities measured from the high temporal resolution EPI method were consistently higher than other approaches, suggesting the importance of temporal resolution on peak velocity quantification.

3851.   13 Highly Accelerated Phase Contrast Imaging using Compressed Sensing and Iterative Reconstruction for High Resolution Short Breathhold Flow Acquisitions
Andreas Greiser1, Michael Zenge1, Michaela Schmidt1, Peter Speier1, and Edgar Mueller1
1Siemens AG Healthcare Sector, Erlangen, Bavaria, Germany

We demonstrate the feasibility of using L1 regularized wavelet based compressed sensing for Cartesian MR flow imaging (CS Flow) with an acceleration factor of R=7.7 and inline reconstruction and compare it to a standard breathhold flow protocol with GRAPPA R=2. Temporal resolution and level of regularization were varied. Forward volume and peak velocity results had similar reproducibility and correlated well with the reference (r2>0.97) but were slightly higher (+4.83%/+7.84%). Stronger regularization improved SNR but temporal fidelity could be maintained. CS Flow can provide higher resolution and shorter breathholds and can easily be integrated in a clinical workflow.

3852.   14 Hemodynamics in a cerebral aneurysm model treated with different flow diverting stent configurations: Assessment using highly accelerated dual-velocity encoded 3D phase-contrast MRI
Daniel Giese1, Christoph Kabbasch1, Dennis Hedderich1, David Maintz1, Thomas Liebig1, and Alexander Bunck1
1Department of Radiology, University Hospital Cologne, Cologne, Germany

The use of a highly accelerated, 3 dimensional, time-resolved, dual-venc phase-contrast acquisition is proposed for the assessment of hemodynamics in aneurysm models treated with different flow diverting devices. It is demonstrated that the use of a dual-venc technique is crucial to successfully depict the required velocity range and that flow conditions differ drastically between the different devices. The results give valuable insights into pre- and postinterventional flow conditions.

3853.   15 Distal cerebral arterial pulsatility using 4D Flow MRI
Anders Wåhlin1,2, Eric Schrauben1,3, Oliver Wieben3, Khalid Ambarki1, Jan Malm4, and Anders Eklund1,5
1Department of Radiation Sciences, Umeå University, Umeå, Sweden, 2Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden,3Department of Medical Physics, University of Wisconsin, Madison, WI, United States, 4Department of Clinical Neuroscience, Umeå University, Umeå, Sweden, 5Center for Biomedical Engineering and Physics, Umeå University, Sweden

Age related high pulsatility of distal brain arteries is thought to damage exposed brain tissue, leading to brain atrophy and cognitive decline among elderly. Previous studies have focused on assessing central pulsatility or pulsatility in cervical arteries feeding the brain. We show that high-resolution 4D Flow MRI is capable of assessing pulsatility of distal branches of the cerebral arterial circulation, a result that should stimulate research aimed for understanding arterial pulsatility as a contributing factor to dementia.

3854.   16 Application of Highly Accelerated Cartesian Phase Contrast Imaging Using Compressed Sensing and Iterative Reconstruction to Real-Time and Vector Encoded Flow Imaging
Andreas Greiser1, Michael Zenge1, Michaela Schmidt1, Mehmet Akif Gulsun2, and Aurelien F. Stalder1
1Siemens AG Healthcare Sector, Erlangen, Bavaria, Germany, 2Imaging and Computer Vision, Siemens Corporation, Corporate Technology, Princeton, NJ, United States

We demonstrate the feasibility of compressed sensing for Cartesian MR flow imaging (CS Flow) with inline reconstruction to enable real-time and high-resolution 3-directional flow imaging. Single-slice phase contrast datasets were acquired using a real-time protocol (R=11.2) and a segmented flow protocol with 3-directional flow encoding with (R=7.7). Real-time results correlated with a segmented reference scan and peak velocity values were in good agreement, flow volumes were overestimated. 3-directional CS Flow could be visualized as velocity magnitude and vectors. CS Flow can enable real-time flow quantification in-cooperative and arrhythmic patients and provides high-resolution vector-encoded flow imaging in a short breathhold.

3855.   17 Automated 4D Flow Whole Vessel Segmentation and Quantification using Centerline Extraction
Eric Schrauben1,2, Anders Wåhlin2,3, Khalid Ambarki2,4, Jan Malm5, Oliver Wieben1,6, and Anders Eklund2,4
1Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin, United States, 2Radiation Sciences, Umeå University, Umeå, Sweden, 3Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Umeå, Sweden, 4Center for Biomedical Engineering and Physics, Umeå University, Umeå, Sweden, 5Clinical Neuroscience, Umeå University, Umeå, Sweden, 6Radiology, University of Wisconsin - Madison, Madison, Wisconsin, United States

This study exhibits the use of a fast and convenient whole vessel segmentation and quantification software tool. Its flexible functionality may be of use in assessment of blood flow variables relevant to clinical pathologies.

3856.   18 Aortic elasticity measured by MRI is decreased during exercise in young adults.
Laurence Bal-Theoleyre1,2, Alain Lalande3, Franck Kober2, Monique Bernard2, and Alexis Jacquier1,2
1Service de Radiologie, AP-HM, Marseille, France, 2CEMEREM (UMR CNRS 7339), Marseille, France, 3LE2I (UMR CNRS 6306), Université de Bourgogne, Dijon, France

The purpose of this study was to compare aortic elasticity measured by MRI in young adults during rest and exercise. On a 1.5 T imager, cine-FISP and sequences with a velocity encoding gradient in the through-plane direction were used to acquire images at different levels of the aorta at rest and during supine exercise on an amagnetic ergometer. Exercise was designed to obtain twice the resting heart rate. Aortic compliance, aortic distensibility and pulse wave velocity were calculated. Stress induced a significant decrease in aortic compliance and distensibility at all sites, associated with an increase of the pulse wave velocity.

3857.   19 Probabilistic Flow Connectivity Mapping with 4D flow MRI data for the Assessment of Blood Mixing in Fontan Circulation
Kelly Jarvis1,2, Susanne Schnell1, Pim van Ooij1, Alex Barker1, James Carr1, Joshua D Robinson3,4, Cynthia Rigsby1,5, and Michael Markl1,2
1Radiology, Northwestern University, Chicago, IL, United States, 2Biomedical Engineering, Northwestern University, Chicago, IL, United States,3Pediatrics, Northwestern University, Chicago, IL, United States, 4Cardiology, Ann & Robert H Lurie Children’s Hospital of Chicago, Chicago, IL, United States, 5Medical Imaging, Ann & Robert H Lurie Children’s Hospital of Chicago, Chicago, IL, United States

Non-uniform blood mixing (distribution of caval venous flow to the left and right lungs) is suspected to cause complications in patients with Fontan circulation. It was the aim of this study to systematically analyze 3D probabilistic flow connectivity mapping and the influence of velocity noise on pathline visualization for a synthetic Fontan phantom and apply these methods in-vivo for the characterization and quantification of blood mixing.

3858.   20 A realistic MR compatible thoracic aortic phantom to study coarctations using catheterization and cine PC-MRI sequences
Jesús Urbina1,2, Julio Sotelo2,3, Israel Valverde4,5, Marcelo Andía2,6, Cristián Tejos2,3, Daniel Hurtado2,7, Pablo Irarrázabal2,3, and Sergio Uribe2,6
1School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile, 2Biomedical Imaging Center, Pontificia Universidad Católica de Chile, Santiago, Chile, 3Electrical Engineering Department, Pontificia Universidad Católica de Chile, Santiago, Chile, 4Pediatric Cardiology Unit, Hospital Virgen del Rocio, Sevilla, Spain, 5Instituto de Biomedicina de Sevilla, Universidad de Sevilla, Santiago, Spain, 6Radiology Department, Pontificia Universidad Católica de Chile, Santiago, Chile, 7Structural Engineering Department, Pontificia Universidad Católica de Chile, Santiago, Chile

Echocardiography is the most available and safe method to study hemodynamics parameters in patient with Aortic Coarctations, however, is operator dependent, pressures are over-estimated. Catheterization is the gold standard, but is invasive, non-exempt of risk and patient have to be exposed to x-ray. New methods need to be developed to obtain hemodynamic parameters no invasively, however developing these methods from patient imaging data is difficult. In this work we have built a realistic MR compatible thoracic aortic phantom to simulate different grade of stenosis, which can be used to validate hemodynamic parameters obtained from PC- MRI data under controlled experiments.

3859.   21 Athero-preventive hemodynamic changes of the abdominal aorta after mild leg stretch & bend exercise assessed with 3D cine phase contrast MRI
Mamoru Takahashi1, Yasuo Takehara2, Haruo Isoda3, Tomoyuki Okuaki4, Yukiko Fukuma4, Norihiro Tooyama5, Katsutoshi Ichijo5, and Harumi Sakahara2
1Seirei Mikatahara General Hospital, Hamamatsu, Japan, 2Hamamatsu University School of Medicine, Japan, 3Department of Radiological and Medical Laboratory Sciences Nagoya University Graduate School of Medi, Japan, 4Philips Electronics Japan, Ltd., Japan, 5Seirei Mikatahara General Hospital, Japan

We could observe hemodynamic changes of the abdominal aorta under progressive lower limb exercise modes with rapid 3D cine PC on wide bore clinical 3.0T MR scanner. Not excessive, but mild exercise mode is optimum for maintaining vascular integrities by increasing the WSS and decreasing the OSI of the abdominal aorta.

3860.   22 4D phase-contrast un-aliasing using both phase and magnitude
Junmin Liu1, Marcus T Alley2, Shreyas Vasanawala2, and Maria Drangova1,3
1Imaging Research Laboratories, Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada, 2Department of Radiology, School of Medicine, Stanford University, Stanford, CA, United States, 3Department of Medical Biophysics, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada

Spatial and temporal unwrapping techniques often fail to successfully un-alias 4D phase images when the data are spatially and temporally undersampled. We developed a new un-aliasing method for 4D flow MRI, which performs 3D spatial phase unwrapping first and then remove temporal phase aliasing using the temporal profiles of unwrapped phase and magnitude. In vivo results demonstrate that incorporating the temporal magnitude profile in the temporal un-aliasing process produces aliasing-free 4D flow images, even when they are acquired with low VENC (~ 50 cm/s), low temporal resolution (~70 ms), and low spatial resolution (e.g. torso imaging).

3861.   23 Accelerated time-resolved Time-Of-Flight Magnetic Resonance Angiography in Mice Models
William Lefrançois1, Charles Castets1, Aurélien Trotier1, Eric Thiaudière1, Jean-Michel Franconi1, and Sylvain Miraux1
1Centre de Résonance Magnétique des Systèmes Biologiques, Bordeaux, France, Metropolitan

Anatomical and functional Time-Of-Flight (TOF) Magnetic Resonance Angiography (MRA) is a powerful tool to investigate vascular function in healthy and diseased small animal models. Nevertheless, this technique can require relatively long acquisition times. The goal of this study was to develop an accelerating strategy to improve blood flow visualisation in mice using a cine-3D echo-planar imaging sequence. This method was applied at 7T in mice to investigate carotid arteries and allowed to divide acquisition times by three compared with the previous functional TOF MRA method using a simple gradient echo sequence.



Tuesday 13 May 2014
Exhibition Hall  13:30 - 14:30

  Computer #  
3862.   25 High Concentration Gadolinium-Based Contrast Reagent Transverse Relaxivities in ex vivo Physiologic Whole Blood and Plasma at 1.5T and 3.0T
Gregory J. Wilson1, Charles S. Springer, Jr.2, Mark Woods2,3, Sarah Bastawrous1,4, Puneet Bhargava1,4, and Jeffrey H. Maki1,4
1Radiology, University of Washington, Seattle, WA, United States, 2Advanced Imaging Research Center, Oregon Health and Science University, Portland, OR, United States, 3Chemistry, Portland State University, Portland, OR, United States, 4Radiology, Puget Sound VA HCS, Seattle, WA, United States

1H2O transverse R2 and R2* relaxation rate constants were measured for gadoteridol, gadobutrol, gadobenate, and gadofosveset concentrations of 0 to 18 mM in oxygenated whole blood and plasma. These values can be used to predict signal intensity during passage of an arterial bolus for contrast-enhanced MRA. R2* values are elevated in whole blood, likely as a result of static dephasing. Exclusion of the contrast reagents from red blood cells creates microscopic gradients in bulk magnetic susceptibility, resulting in fast dephasing of 1H2O signal in whole blood.

3863.   26 A Multicenter MRI Protocol for the Evaluation and Quantification of Deep Vein Thrombosis
Venkatesh Mani1, Sarayu Ramachandran1, Philip M Robson1, Nadia Alie1, Cecilia Besa1, Gregory Piazza2, Michael Grosso3, Michele Mercuri3, Samuel Z Goldhaber2, Bachir Taouli1, and Zahi A Fayad1
1Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Brigham and Women’s Hospital, Boston, MA, United States, 3Daiichi Sankyo Pharma Development, Edison, NJ, United States

In a study of edoxaban monotherapy for acute, symptomatic DVT treatment (eTRIS), we are utilizing a novel MR venography approach using a 3D VIBE sequence with Ablavar® as a contrast agent to quantify total thrombus volume changes as an assessment of treatment efficacy.Here we demonstrate the reproducibility of the image analysis approach used for this trial.

3864.   27 Error in the Reproducibility of Volume Measurements in Patients with Stable Intracranial Aneurysms Imaged at 1.5T & 3T
Farshid Faraji1, Donne Nieuwoudt1, Alastair Martin2, and David Saloner1
1Radiology & Biomedical Imaging, UCSF/VAMC, San Francisco, CA, United States, 2Radiology & Biomedical Imaging, UCSF, San Francisco, CA, United States

Intracranial aneurysms are localized blood vessel dilations that can have dangerous sequellae in the event of rupture. Although there are treatment options, it is unclear whether the risks of surgery outweigh the benefits, especially in cases of asymptomatic aneurysms below a certain size threshold. Many patients opt for "watchful waiting", which necessitates accurate, reproducible, non-invasive imaging to assess disease progression. In this study, we investigate the error in the reproducibility of volumetric measurements in patients with stable intracranial aneurysms who have had repeat contrast-enhanced MR angiography at both 1.5 and 3T.

3865.   28 Evaluation of Non Contrast Enhanced MRA in patients with PVD
Nadeem Shaida1, Andrew Priest2, Teik Choon See1, Andrew Winterbottom1, Martin Graves2, and David Lomas3
1Department of Radiology, Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom, 2Department of Medical Physics, Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom, 3University Department of Radiology, Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom

Non-contrast enhanced MRA is an emerging imaging modality which may prove to be of clinical use in the typical population of elderly arteriopaths with impaired renal function. Here we compare two such novel subtraction based MRA techniques based on flow velocity and flow acceleration with conventional contrast enhanced MRA.

3866.   29 eXtended – Time Resolved Angiography using InfLow Subtraction (X-TRAILS) - permission withheld
Daniel Kopeinigg1 and Roland Bammer1
1Stanford University, Stanford, California, United States

A novel extension to time resolved angiography using inflow subtraction (X-TRAILS) is presented. It employs variable repetition times (vr-TR) to reduce RF exposure during the multiphase 3D Cones readout to accommodate patients that exhibit extremely slow intravascular flow patterns. Bloch simulation including a feasibility study on subjects is performed. X-TRAILS allows whole head coverage and the acquisition of both static and dynamic angiographic high resolution datasets in a single scan.

3867.   30 Initial evaluation of non-contrast-enhanced MRA in patients with peripheral arterial occlusive disease at 7 T
Anja Fischer1,2, Stefan Maderwald1,2, Sören Johst1,2, Stephan Orzada1,2, Mark E. Ladd2,3, Lale Umutlu1,2, Thomas C. Lauenstein1, Horst-Wilhelm Kniemeyer4, and Kai Nassenstein1
1Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany, 2Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany, 3Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany, 4Clinic for Vascular Surgery, Elisabeth Hospital Essen, Essen, Germany

The purpose of this study was to achieve initial experience with non-contrast-enhanced MRA at 7 T in patients with PAOD. T1w Turbo-FLASH imaging was performed on a 7 T whole-body scanner utilizing a 16-channel transmit/receive coil and an AngioSURF table in addition to contrast-based MRA at 1.5 T. The number of stenoses and occlusions was counted for each arterial segment in both MRA techniques. Arterial anatomy was accurately demonstrated at 7 T both proximal and distal to stenotic disease. The sensitivity and specificity values of 7 T ne-MRA for detecting segments with hemodynamically significant stenosis were 93% and 98%, respectively.

3868.   31 Volumetric Phase Contrast Imaging of the Hepatic Vasculature
Joseph W Owen, MD1, Kathryn J Fowler, MD1, Nael E Saad, MBBCh1, Agus Priatna2, Michael Crowley, PhD1, and Vamsi R Narra, MD, FRCR1
1Mallinckrodt Institute of Radiology, Washington University, Saint Louis, MO, United States, 2Siemens Healthcare USA, Ballwin, MO, United States

Portal hypertension (PHTN) creates complex flow dynamics. Treatments aim to reduce the morbidity by reducing the portosystemic gradient and/or treating varices. Treatments have variable success depending on flow dynamics in the portal venous system. We successfully imaged normal patients, patients with PHTN and patients after placement of TIPS with volumetric phase contrast free breathing technique. The results were compared with invasive wedge and free hepatic vein pressures and Doppler ultrasound. In the future, volumetric phase contrast MRI may provide reproducible user-independent velocity and flow quantification information in a patients with PHTN assisting in both pre-procedure planning and post-procedure follow-up.

3869.   32 Refined Balanced Steady-State Free Precession in Breath-hold Coronary MRA at 3.0T
Sahar Soleimanifard1, Matthias Stuber1,2, Allison G Hays1, Robert G Weiss1, and Michael Schar1,3
1Johns Hopkins University, Baltimore, Maryland, United States, 2University of Lausanne, Lausanne, Switzerland, 3Philips Healthcare, Cleveland, Ohio, United States

Utilization of balanced steady-state free precession (bSSFP) at 3.0T is significantly hampered by the elevated B0 and local RF field inhomogeneities that generally lead to degraded image quality. In this work, we propose a refined sequence with binomial pre-saturation and Kaiser-Bessel startup pulses to provide a more homogeneous excitation and to suppress the well known dark band artifacts. This sequence, incorporating VERSE pulses and parallel imaging, achieves acquisition of a 3D targeted volume covering the major coronaries within a single breath-hold. Initial studies in healthy subjects and in a patient with established coronary artery disease demonstrate image quality improvements in breath-hold bSSFP at 3.0T.

3870.   33 Non-Contrast MRA using magnetization transfer (MT) preparation with a zero echo-time (ZTE) acquisition
James H Holmes1, Patrick A Turski2, Frank R Korosec2, Ersin Bayram3, and Kevin M Johnson4
1Global MR Applications and Workflow, GE Healthcare, Madison, WI, United States, 2Radiology, University of Wisconsin-Madison, Madison, WI, United States,3Global MR Applications and Workflow, GE Healthcare, Houston, WI, United States, 4Medical Physics, University of Wisconsin-Madison, Madison, WI, United States

Current trends in medicine are moving toward minimally invasive diagnosis. These include needle-free non-contrast MRI methods. Acoustic noise still remains a challenge using conventional imaging methods. The hypothesis of this work is that a Magnetization transfer preparation pulse combined with a zero-TE data acquisition can provide non-contrast MRA with minimal acoustic noise.

3871.   34 Free-Breathing 3D Isotropic Whole Chest Non-Contrast MRA Using a Combination of Compressed Sensing, Parallel Imaging and a 3D Radial Phyllotaxis Trajectory: a Feasibility Study
Jian Xu1,2, Li Feng3, Ruth P. Lim4, Davide Piccini5,6, Ricardo Otazo3, Gabriele Bonanno5, Yi Wang7, Edward K. Wong1, and Daniel K. Sodickson3
1Department of Computer Science and Engineering, Polytechnic Insitute of New York University, Brooklyn, NY, United States, 2Siemens HealthCare USA, NY, United States, 3Department of Radiology, New York University School of Medicine, NY, United States, 4Department of Radiology, Austin Health, Victoria, Australia, 5Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL) / Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, 6Advanced Clinical Imaging Technology, Siemens Healthcare IM BM PI, Lausanne, Switzerland, 7The DeMatteis Center, St. Francis Hospital, Roslyn, NY, United States

This work demonstrates the feasibility of 3D isotropic whole chest non-contrast MRA in approximately 2 minutes using a joint multicoil compressed sensing reconstruction with a 3D radial phyllotaxis trajectory. Respiratory motion correction was implemented in k-space before image reconstruction to achieve 100% acquisition efficiency. The proposed approach offers potential applications for morphologic evaluation of the heart and thoracic vessels in clinically acceptable scan times. The high isotropic spatial resolution further enables simplified data acquisition and offline evaluation of the vessels in different planes with arbitrary image reformation. The method has additional potential applications in the diagnosis of congenital heart disease or aortopathy.

3872.   35 High Resolution Imaging of Peripheral Arteries with 3D Quiescent-Interval Single-Shot (QISS) Non-enhanced Magnetic Resonance Angiography
Huan Tan1, Shivraman Giri2, Ioannis Koktzoglou1,3, and Robert R Edelman3,4
1University of Chicago, Chicago, IL, United States, 2Siemens Healthcare, Chicago, IL, United States, 3Northshore University HealthSystem, Evanston, IL, United States, 4Northwestern University, Chicago, IL, United States

We have developed a 3D-QISS technique for high resolution (through-plane: 0.3 mm), non-enhanced peripheral MRA. The proposed method is a modification of the quiescent-interval single-shot (QISS) technique with a 3D TrueFISP readout and spectral selection attenuated inversion recovery (SPAIR) for fat suppression. QISS3D demonstrated excellent image quality, improved venous suppression, and superior signal-to-noise ratios.

3873.   36 3D Radial Spin-Labeled MRA of the Extracranial Carotid Arteries: Optimization and Potential for Rapid Imaging
Ioannis Koktzoglou1,2, William J Ankenbrandt1,2, Joel R Meyer1,2, Shivraman Giri3, Davide Piccini4, Michael O Zenge5, Oisin Flanagan6, Tina Desai1,2, NavYash Gupta1,2, and Robert R Edelman1,6
1NorthShore University HealthSystem, Evanston, IL, United States, 2The University of Chicago Pritzker School of Medicine, Chicago, IL, United States,3Siemens Healthcare, Chicago, IL, United States, 4Advanced Clinical Imaging Technology, Siemens Healthcare, Lausanne, Switzerland, 5MR Product Innovation and Definition, Healthcare Sector, Siemens AG, Erlangen, Germany, 6Northwestern University Feinberg School of Medicine, Chicago, IL, United States

The purpose of this study was to optimize and evaluate a 3D radial balanced steady-state free precession arterial spin labeled imaging sequence for high-contrast, rapid nonenhanced MR angiography of the extracranial carotid arteries. Through the use of higher radial undersampling, the the feasibility of rapid carotid MR angiography with the technique was also evaluated.

3874.   37 Fresh Blood Imaging (FBI) of Peripheral Arteries: Interobserver and Intraobserver Reproducibility Study
Katsumi Nakamura1,2, Akiyoshi Yamamoto1, Hiroki Matoba1, Daiji Uchiyama1, Seigo Yoshida1, and Mitsue Miyazaki3
1Radiology, Tobata Kyoritsu Hospital, Kitakyushu, Fukuoka, Japan, 2Radiology, Hikari Central Hospital, Hikari, Yamaguchi, Japan, 3Toshiba Medical Research Institute USA, Inc, IL, United States

Interobserver and intraobserver reproducibility in the interpretation of Fresh Blood Imaging (FBI) of peripheral arteries were substantial, and were clinically acceptable.

3875.   38 Non contrast enhanced MRA of the supra-aortic arteries with compressed sensing and parallel imaging
Takayuki Masui1, Motoyuki Katayama1, Naoyuki Takei2, Kevin F King3, Kimihiko Sato1, Kei Tsukamoto1, Kenichi Mizuki1, Masayoshi Sugimura1, and Koji Yoneyama1
1Radiology, Seirei Hamamatsu General Hospital, Hamamatsu, Shizuoka, Japan, 2GE Healthcare Japan, Hino, Tokyo, Japan, 3GE Healthcare, Waukesha, Wisconsin, United States

Noncontrast-enhanced MRA with investigational version of IFIR FSE can be obtained for evaluation of arteries from aortic arch to skull base with compressed sensing (CS) and parallel imaging ARC within a short period time. Thirty-seven patients with possible cerebrovascular diseases were studied. Reduction of imaging time of MRA with acceptable image quality can be made with ARC 3x2 or ARC 3x1+CS. This technique can be used as a screening method for neck arteries additional to MRI and MRA of the head. Further optimization of sequences for ARC and CS may be required for reduction of imaging time.

3876.   39 Noncontrast MRA of Abdominopelvic Arteries Using Quadruple Inversion-Recovery Preconditioning and 3D Balanced Steady-State Free Precession Imaging at 3T
Marc D Lindley1, Daniel Kim1, Glen Morrell1, Marta E Heilbrun1, Christopher J Hanrahan1, and Vivian S Lee1
1UCAIR, Radiology, University of Utah, Salt Lake City, Utah, United States

Non-contrast (NC) abdominal MRA using quadruple inversion-recovery (QIR) magnetization preparation and 3D balanced SSFP readout has been developed and evaluated at 1.5T. NC-MRA at 3T presents an opportunity to increase the overall signal-to-noise ratio. We modified the imaging protocol to make QIR NC-MRA compatible at 3T. In one volunteers, both 1.5T and 3T QIR-NC MRA results exhibited similarly high quality maximum-intensity-projection (MIP). In one patient with vascular disease, QIR-NC MRA and contrast-enhanced MRA exhibited similarly high quality MIP at 3T. This study suggests that it is feasible to perform high-quality QIR-NC MRA at 3T.

3877.   40 Imaging with Full Static Tissue Suppression for 3D Volume Rendered (VR) Intracranial Angiography: Application of DANTE-Prepared FLASH (3D-DASH) to Magnetic Resonance Angiography
Linqing Li1, Olivia Viessmann1, Thomas W. Okell1, Francesca Galassi2, and Peter Jezzard1
1FMRIB Centre, Clinical Neuroscience Department, University of Oxford, Oxford, United Kingdom, 2Acute Vascular Imaging Centre, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom

We demonstrate a high-resolution 0.5 mm isotropic volume rendering dataset created from digital subtraction of 3D TOF and 3D-DANTE prepared FLASH (3D-DASH) black blood images, showing significant improvement in revealing small arteries. In addition, the visualization quality of the MIP images generated from a subtracted dataset is greatly improved in comparisons to its original TOF version.

3878.   41 Usefulness of Vessel Selective 4D-MR Angiography for Intracranial Arteriovenous Malformation
Noriyuki Fujima1, Hiroyuki Sugimori1, Yuriko Suzuki2, Kohsuke Kudo1, and Hiroki Shirato3
1Hokkaido University Hospital, Sapporo, Hokkaido, Japan, 2Philips Electronics Japan, Tokyo, Japan, 3Hokkaido University, Graduate School of Medicine, Hokkaido, Japan

In recent years, time-resolved 4D-MRA technique based on arterial spin labeling (ASL) methods has been widely reported. In addition, vessel selective 4D-MRA (VS 4D-MRA) can be obtained using spatial free labeling slab based on pulsed ASL technique. The aim of this study was to assess the usefulness of VS 4D-MRA for the assessment of feeding artery in intracranial AVM. This study revealed that additional information of feeding arterial flow was obtained using VS 4D-MRA compared to conventional TOF-MRA. This technique can be useful for the evaluation of intracranial AVM as additional information.

3879.   42 Double Background Suppression in Quiescent Inflow Single-Shot Imaging at 3T
Xiangzhi Zhou1, Cheng Ouyang1, Aiming Lu1, and Mitsue Miyazaki1
1Toshiba Medical Research Institute, Vernon Hills, IL, United States

Background suppression (BGS) in QISS is performed by an imaging slice saturation pulse. We hypothesize that the extended tracking saturation pulse together with the imaging saturation pulse may offer improved background suppression. We tested three BGS methods at calf station at 3T: A) using the imaging slice saturation for single background suppression; B) extended tracking saturation slice to cover the imaging slab for double background suppression; C) extended tracking saturation slab for background suppression without imaging slice saturation pulse. We found that double BGS can greatly reduce the background signal and offers the highest CNR for arterial blood signal.

3880.   43 Cardiac Gating Calibration by the MR Septal Scout
Garry Liu1 and Graham A Wright2
1Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada, 2Sunnybrook Health Sciences Centre, Ontario, Canada

A high temporal-resolution MRI technique, the Septal Scout, was developed and used to measure the long-axis motion of the interventricular septum for the purpose of determining, with greater accuracy, quiescent cardiac imaging windows. The Septal Scout, compared with cine-SSFP in a healthy volunteer study produced more accurate cardiac gating windows and obtained sharper coronary artery images during single breath-hold non-contrast-enhanced coronary MR angiography.

3881.   44 Non-Contrast-Enhanced Pulmonary MR Angiography based on ECG-gated 3D time-spatial labeling inversion pulse (Time-SLIP) Technique: Influence of Tag Pulse Position for Separation of Pulmonary Arteriogram and Pulmonary Venogram -permission withheld
Yoshiharu Ohno1, Nobukazu Aoyama2, Shinichiro Seki3, Mizuho Nishio1, Hisanobu Koyama3, Takeshi Yoshikawa1, Sumiaki Matsumoto1, Yoshimori Kassai4, Masao Yui4, Katsusuke Kyotani2, Hideaki Kawamitsu2, and Kazuro Sugimura3
1Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, 2Center for Radiology and Radiation Oncology, Kobe University Hospital, Kobe, Hyogo, Japan, 3Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, 4Toshiba Medical Systems Corporation, Otawara, Tochigi, Japan

No one has assessed the influence of slice-selective Tag pulse position for separation of pulmonary venography from atreiography using time-SLIP technique. We hypothesized that non-CE-MRA using time-SLIP technique at 3T had significant influence of slice-selective Tag position to separately visualize pulmonary vein from artery. The purpose of this study was thus to prospectively and directly compare the influence of slice-selective Tag position for separation of pulmonary vein from artery on non-CE-MRA with time-SLIP technique at in vivo study.

3882.   45 Evaluation of patients of the cerebral vasculature: Comparison with Silenz MRA and 3D TOF MRA.
Kenichi Mizuki1, Takayuki Masui1, Motoyuki Katayama1, Kimihiko Sato1, Kei Tsukamoto1, Nami Matsunaga2, Miyoshi Mitsuharu2, Hiroyuki Kabasawa2, and Harumi Sakahara3
1Seirei hamamatsu general hospital, hamamatsu, shizuoka, Japan, 2GE healthcare, Tokyo, Japan, 3Hamamatsu university school of medicine, shizuoka, Japan

Silent Scan (Silenz, GEHC) is designed almost to eliminate noise during MR scanning by reducing rapid gradient switching using ultrashort TE. The purpose was to compare Silenz MRA (Silenz) based on arterial spin labeling with TOF MRA for evaluation of intracranial arteries. In 25 of 27 patients, Silenz provides homogenous SI of vasculatures and all aneurysmal lesions were recognized. In two cases, distal part of arteries were failed to visualize and aneurysm was missed. Silenz may provide information of intracranial arteries without noise. However, further optimization of Silenz might be required to constantly visualize intracranial arteries with various flow velocities.

3883.   46 Assessing the “Possible Intracardiac Mass”: Methodological Imaging and Interpretation of Cardiovascular Magnetic Resonance Findings
W. Patricia Bandettini1, Marcus Y Chen1, Sujata M Shanbhag1, and Andrew E Arai1
1NHLBI Advanced Cardiovascular Imaging, National Heart, Lung, and Blood Institute, Bethesda, Maryland, United States

This educational presentation reviews the methodological imaging and interpreting process that constitute the cardiovascular magnetic resonance (CMR) assessment of “possible intracardiac mass”. We present a text and pictorial summary of various intracardiac masses to demonstrate the heterogeneity commonly seen in tissue characterization, using T1, T2, fat-suppression, fat-water separation, perfusion, and late gadolinium enhancement techniques. While some masses have “typical” tissue characteristic presentations, the physician needs to be judicious in interpreting the CMR. CMR can identify normal structures that may appear as a “pseudo-mass” on other imaging modalities, and CMR can differentiate between cysts, vascular structures, fat, thrombi, and solid tumors.

3884.   47 R2* Magnetic Resonance in the Evaluation of Cardiac Iron
Daniel Jeong1, Diego Hernando1, Karl K. Vigen1, Mark L. Schiebler1, Christopher J. Francois1, Scott K. Nagle1,2, and Scott B. Reeder1,2
1Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, United States

Accurate measurement of cardiac iron is critical to the early detection of iron overload in patients at risk of siderotic cardiomyopathy and heart failure. Cardiac R2/T2-star (T2*) magnetic resonance has become a reliable, noninvasive, and reproducible method for the quantification of myocardial iron. The purpose of this educational exhibit is to describe the basic principles of R2* magnetic resonance techniques in the quantification of cardiac iron, illustrate the appearance of iron overload syndromes in magnetic resonance imaging, and review the current evidence related to the clinical application and significance of R2* magnetic resonance in monitoring cardiac iron stores.


Myocardial Function

Tuesday 13 May 2014
Exhibition Hall  13:30 - 14:30

  Computer #  
49 Tissue Phase Mapping analysis of IKr-blocker E4031 effects on mechanical cardiac function in transgenic long-QT syndrome type 1 rabbits
Marius Menza1, David Ziupa2, Julia Beck2, Gerlind Franke2, Stefanie Perez Feliz2, Michael Brunner2, Gideon Koren3, Manfred Zehender2, Daniela Föll2, Bernd A. Jung1, and Katja E. Odening2
1Department of Radiology - Medical Physics, University Medical Center, Freiburg, Germany, 2Department of Cardiology and Angiology I, University Medical Center, Freiburg, Germany, 3Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States

A variety of different drugs block cardiac IKr-currents thus causing a serious side effect, the so called acquired Long-QT syndrome with a prolongation of cardiac repolarization (prolonged QT interval) and sudden cardiac death. Using Tissue Phase Mapping, we investigated the influence of IKr-blocking drug E4031 on global and segmental mechanical cardiac function in transgenic LQT type 1 rabbits (loss of IKs, with a particularly high susceptibility to IKr-blocking drugs) and wild-type littermate controls.

3886.   50 Inline generation of tagline density maps for radial strain quantification from circular MR tagging
Ali Aghaeifar1, Abbas N Moghaddam1,2, and J. Paul Finn2
1BME, Tehran Polytechnic, Tehran, Tehran, Iran, 2Radiological Science, UCLA, Los Angeles, CA, United States

Many of cardiac diseases are resulted in myocardium contractility alteration. Tagging, a labeling method of myocardium in cardiovascular MRI, is the preferred choice for assessment of left ventricular (LV) mechanical parameters. In this study, using circular shaped tags, we proposed method with high clinical impact to inline generation of density map in order to quantify radial strain of LV. The method successfully was implemented and tested on the 1.5T and 3T clinical MR scanner.

51 Tissue Phase Mapping Using Single Breath-hold 4D PCMR
Jennifer Anne Steeden1, Grzegorz Kowalik1, Andrew Taylor1, and Vivek Muthurangu1
1Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London, United Kingdom

Magnetic resonance tissue phase mapping (TPM) allows assessment of the separate directional components of wall motion. The purpose of this study was to develop a highly accelerated 4D PCMR sequence (R=8, using SENSE and UNFOLD) to acquire TPM data across the entire left ventricle, during a single breath-hold (of 16 heartbeats). Data was acquired in 5 healthy volunteers and 1 patient. Evidence of dyssynchrony in early LV diastole was seen in the patient, as well as significantly lower longitudinal velocities compared to healthy volunteers. We show that using a novel spiral UNFOLD SENSE PCMR sequence it is possible to obtain 4D TPM data in a single breath-hold.

52 Highly Accelerated Cine DENSE MRI with k-t SPARSE SENSE
Elwin Bassett1, Ricardo Otazo2, Li Feng2, Ganesh Adluru3, Edward DiBella3, and Daniel Kim3
1Physics, University of Utah, Salt Lake City, Utah, United States, 2Radiology, New York University, New York, United States, 3UCAIR, Radiology, University of Utah, Salt Lake City, Utah, United States

Displacement encoding with stimulated echoes (DENSE) MRI is a promising method to quantify myocardial strain. While 2-fold accelerated cine DENSE MRI using TSENSE has been validated, its breath-hold duration (12 heart-beats) may still be too long for critically ill patients. We have retrospectively undersampled full DENSE data sets in two volunteers at acceleration factors of 4 and 8 and reconstructed them using k-t SPARSE SENSE parameters. Compared with circumferential shortening strain from the fully sampled data sets, strain from 4-fold and 8-fold undersampled data sets agreed well, suggesting feasibility of highly-accelerated cine DENSE MRI with k-t SPARSE-SENSE.

3889.   53 Effect of LV pacing lead position and presence of ventricular dyssynchrony on response to cardiac resynchronization therapy: A CMR study
Gregory Hartlage1, Jonathan Suever2, Stephanie Clement-Guinaudeau3, Patrick Strickland1, Patrick Magrath3, Michael Lloyd1, and John N Oshinski2,3
1Cardiology, Emory University School of Medicine, Atlanta, GA, United States, 2Georgia Institute of Technology, Atlanta, GA, United States, 3Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, United States

We show that the presence of left ventricular dyssynchrony and optimal lead location are linked to patient response to cardiac resynchronization therapy (CRT).

3890.   54 Characterization of Cardiac Function in Naïve Non-Human Primates Using Strain and Flow Based MRI Biomarkers: A Test-Retest Reproducibility and Inter-Animal Variability Study
Smita Sampath1, Michael Klimas2, Richard Baumgartner3, Dai Feng3, Elaine Manigbas4, Ai-Leng Liang1, Brian Henry1, Jeffrey L Evelhoch2, and Chih-Liang Chin1
1Translational Medicine Research Center, Merck Sharp and Dohme, Singapore, Singapore, Singapore, 2Imaging, Merck & Co. Inc., West Point, Pennsylvania, United States, 3Biometric Research, Biostatistics and Research Decision Sciences, Merck & Co. Inc., Rahway, New Jersey, United States,4Imaging, Maccine Pte. Ltd., Singapore, Singapore

Translational pre-clinical non-human primate (NHP) models offer a unique framework to evaluate novel therapeutics for human diseases. Herein, we characterize cardiac function in NHPs using optimized MR tagging and phase-contrast imaging on a 3T MRI scanner. Our results describe regional strain and flow characteristics and their temporal relationships during systolic pumping and diastolic filling. We also demonstrate good intra-subject reproducibility and acceptable inter-subject variability in quantitative strain and flow based imaging biomarkers. Prospective power analyses support the future application of these non-invasive functional biomarkers to evaluate longitudinal changes in cardiac function during drug safety or efficacy studies of experimental compounds.

3891.   55 Evaluating both “Normal” and “Ectopic” Cardiac Cycles in Patients with Arrhythmias Using Free-Breathing Compressed Sensing MRI with Physiological Motion Synchronization
Li Feng1, Leon Axel1, Darragh Halpenny1, Larry Latson1, Jian Xu2, Daniel K Sodickson1, and Ricardo Otazo1
1Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University, School of Medicine, New York, New York, United States, 2Siemens Medical Solutions, New York, New York, United States

Evaluation of myocardial function using MRI is challenging in patients with arrhythmias, due to the difficulty of synchronizing disparate cardiac cycles. In order to achieve successful reconstruction, “ectopic” cardiac cycles are usually detected and discarded, which may potentially lose some clinically useful information. In this work, we propose to acquire data continuously using golden-angle radial trajectories in free-breathing and detect cardiac cycles with differing lengths, followed by reconstruction with synchronized but separated cardiac and respiratory dimensions, including separate “normal” and “ectopic” cardiac cycles, which provides additional information for potential clinical use. The method was compared to the conventional breath-hold approach.

3892.   56 Accelerated Cine DENSE using Variable Density Spirals and Compressed Sensing with Parallel Imaging
Xiao Chen1, Yang Yang1, Michael Salerno2,3, Craig H. Meyer1, and Frederick H. Epstein1
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, 2Radiology, University of Virginia, Charlottesville, VA, United States,3Cardiology, University of Virginia, Charlottesville, Virginia, United States

Cine DENSE (Displacement Encoding with Stimulated Echoes) provides accurate and high-resolution displacement and strain imaging of the heart; however, image acquisition times are relatively long and, due to properties inherent to stimulated echoes, signal-to-noise ratio (SNR) is relatively low. In this study, using variable-density spiral acquisitions with golden angle rotations and BLOSM-SENSE reconstruction, accelerated cine DENSE images with two-dimensional in-plane displacement encoding can be acquired in a single breathhold, as short as 8 heartbeats. This represents a significant improvement over prior protocols that used two 14-heartbeats breathholds to acquire equivalent datasets.

3893.   57 A robust and fast SSFP cine for the evaluation of LV function at 3T
Yin Wu1,2, Yinzhu Gao1,2, Ke Jiang1,2, Yucheng Chen3, and Yiu-Cho Chung1,2
1Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Key Laboratory for MRI, Shenzhen Institutes of Advanced Technology, Shenzhen, Guangdong, China, 2Key Laboratory of Health Informatics, Chinese Academy of Sciences, Shenzhen, Guangdong, China, 3Cardiology Department, West China Hospital, Sichuan University, Chengdu, Sichuan, China

3T MRI is advantageous to CMR, but its main field inhomogeneity often introduces banding artifacts in SSFP cine. In this study, we propose an SSFP cine protocol with a shorter TR by using a slightly lower spatial resolution and a fast RF pulse. 10 healthy volunteers and 6 cardiac patients were scanned using the new protocol and compared with the standard SSFP protocol at 3T. Results show that the shorter TR improves robustness of SSFP cine to field inhomogeneity and shortens scan time without affecting LV function measurements. The proposed approach is a robust, fast and accurate way for SSFP cine at 3T.

3894.   58 Single Beat Approach to Left Ventricular Diastolic Chamber Stiffness Independent of Relaxation Time Constant Tau
Chun Schiros1, Thomas Denney2, Jose Tallaj3, Gilbert Perry3, Steven Lloyd3, Louis Dell’Italia3, and Himanshu Gupta3
1University of Alabama at Birmingham, Birmingham, Alabama, United States, 2Auburn University, Alabama, United States, 3University of Alabama at Birmingham, Alabama, United States

Due to incomplete left ventricular (LV) relaxation, relaxation time constant τ is used to correct for minimum pressure in computing LV diastolic chamber stiffness, an important diastolic parameter from single beat. However, τ is affected by heart rate and indirectly by LVEDP. Further, there are multiple methodologies for calculating τ, resulting in various τ values. Therefore, the corrected minimum pressure and volume corresponding to 3.5τ, where LV is considered completely relaxed, may not be always reliable. Here we propose a novel single beat approach to corrected LV diastolic chamber stiffness independent of τ utilizing cMRI LV volumetric measurements.

3895.   59 A Dedicated 64-Channel Cardiac Receive-Only Phased Array Coil: Initial Experience
Mark Schuppert1, Michaela Schmidt2, Karl Friedrich Kreitner3, Boris Keil4, Bastien Guerin4, Stefan Fischer1, Joerg Rothard2, Lawrence L. Wald4,5, and Laura M. Schreiber1
1Section of Medical Physics, Department of Radiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany, 2Siemens AG, Healthcare Sector, Erlangen, Germany, 3Department of Radiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany,4A.A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States, 5Harvard Medical School, Boston, MA, United States

A new 64-channel cardiac phased array prototype coil was compared to a commercial 30-channel coil setup (Body 18/Spine 32 Tim coils) to assess imaging performance in healthy volunteers. Accelerated cine cardiac MRI (tGRAPPA, acceleration factors R = 3, 5, 7, and 8) was performed in short-axis and four-chamber views. MR images were scored by an independent radiologist for image quality in terms of diagnostic value (1 = Excellent, 2 = Good, 3 = Satisfactory, 4 = Fair, 5 = Fail). The 64-channel coil outperformed the commercial setup at R = 5 and R = 7, resulting in lower score values.

3896.   60 Cardiac Cine MRI for Mice with Myocardial Infarction using 3D Self-gated Radial Gradient Echo -permission withheld
Naoharu Kobayashi1, Qiang Xiong2, Jing Guo2, Jianyi Zhang2, and Michael Garwood1
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, United States, 2Department of Medicine, University of Minnesota Medical School, Minnesota, United States

A radial gradient echo sequence with cardiac self-gating is introduced for 3D cine imaging of mice with myocardial infarction (MI). Accuracy of the MR self-gating was validated by comparing with ECG signals. In order to accelerate 3D acquisition, compressed sensing reconstruction was applied and predominantly removed undersampling artifacts and noise, resulting in reasonable scan time in animal experiments (14 min). The proposed methods visualized dynamics of cardiac function for MI mice with various infarct sizes; the 3D self-gated cine MRI technique is robust for MI mice with severe arrhythmia associated with significantly adverse left ventricular remodeling.

3897.   61 3D kat ARC cine for evaluating cardiac function on 3T
Shigeo Okuda1, Yoshitake Yamada1, Akihiro Tanimoto1, Jun Fujita2, Motoaki Sano2, Keiichi Fukuda2, Sachio Kuribayashi1, Atsushi Nozaki3, and Peng Lai4
1Diagnostic Radiology, Keio University School of Medicine, Tokyo, Japan, 2Cardiology, Keio University School of Medicine, Tokyo, Japan, 3MR Applications & Workflow, GE Healthcare, Hino, Japan, 4MR Applications & Workflow, GE Healthcare, Menlo Park, CA, United States

Whole-heart 3D cine was obtained in 18 sec using kat ARC technique with acceleration factor of 7.7, following SSFP 2D cine of the left ventricular (LV) short axis in 21 patients on 3T. LV functional parameters including EDV, ESV, SV, EF, Mass were compared between 2D and 3D cine. Bland-Altman analysis revealed the interchangeability of parameters between 2D and 3D cine, and inter- and intra-observer variability were excellent in both techniques. 3D kat ARC cine enables accurate clinical evaluation of cardiac function within a single breathhold.

3898.   62 Beat-specific estimate of PVC-compromised cardiac function via non-gated free-breathing MRI
Dariya I. Malyarenko1, Thomas L. Chenevert1, Gisela C. Mueller1, Justin Saunders2, Frank M. Bogun2, and Scott D. Swanson1
1Radiology, University of Michigan, Ann Arbor, MI, United States, 2Internal Medicine: Cardiology, University of Michigan, Ann Arbor, MI, United States

Improved imaging techniques are needed for early assessment of left ventricular dysfunction in patients with frequent premature ventricular contractions (PVCs). Accurate beat-specific assessment of cardiac function is required for appropriate disease prognosis and therapy choice. Conventional cardiac MRI acquisition is compromised by arrhythmia-rejection data filtering and breath-hold induced variations in cardiac function. This preliminary study evaluates free-breathing non-gated real time MRI acquisition retrospectively synchronized with physiological data for cardiac function analysis during PVCs.

3899.   63 Quantitative analysis of dyssynchrony using cardiovascular magnetic resonance tagging imaging in idiopathic dilated cardiomyopathy
Tatsuya Nishii1, Atsushi K Kono2,3, Katsusuke Kyotani4, Kouya Nishiyama4, Mayumi Shigeru5, Sachiko Takamine5, Sei Fujiwara5, and Kazuro Sugimura1
1Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, 2Department of Radiology, Kobe University Hospital, Kobe, Hyogo, Japan, 3Department of Radiology, Erasmus Medical Center, Rotterdam, Netherlands, 4Division of Radiology, Kobe University Hospital, Kobe, Hyogo, Japan, 5Division of Cardiovascular and Respiratory Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan

The tagging imaging on cardiovascular magnetic resonance evaluates the dynamic deformation of lines or grids superimposed on the myocardium during the cardiac cycle, and also provides the quantitative parameters as well as strain. The sensitivity and quantitative capability of tagging imaging for detecting the deformation of myocardium in ischemic heart disease had been reported. We hypothesized the feasibility of tagging imaging for detecting the details of myocardial dysfunction as well as dyssynchrony of idiopathic dilated cardiomyopathy (DCM). The purpose of this study was to evaluate the details of myocardial dysfunction in DCM patients using tagging imaging.

3900.   64 Cine DENSE Strain Imaging of the Right Ventricle: Initial Experience in Heart Failure
Sophia Cui1, Andrew D. Gilliam2, Kenneth C. Bilchick3, and Frederick H. Epstein1,4
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, 2A.D. Gilliam Consulting, Providence, RI, United States,3Cardiovascular Medicine, University of Virginia, Charlottesville, VA, United States, 4Radiology, University of Virginia, Charlottesville, VA, United States

We evaluated cine DENSE MRI for the assessment of right ventricular (RV) strain. Normal RV function was defined by imaging subjects without heart disease. HF patients demonstrated significant RV dysfunction as compared to subjects without heart disease, and an association was found between LV dyssynchrony and RV prestretch, suggesting a previously unrecognized deleterious effect on the RV due to LV dyssynchrony. Long-axis cine DENSE MRI may provide new clinical insights regarding RV dysfunction.

3901.   65 The Impact of Cystic Fibrosis on Cardiac Function and Stress Response
Kai Jiang1,2, Sen Jiao1,2, Craig A. Hodges3,4, Rebecca Darrah4, and Xin Yu1,5
1Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Case Medical Center, Case Western Reserve University, Cleveland, Ohio, United States, 3Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio, United States, 4Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, United States, 5Department of Radiology, Case Western Reserve University, Cleveland, Ohio, United States

In this study, cardiac function of two mouse models of cystic fibrosis (CF) was characterized both in vivo and in vitro. An increase in ventricular torsion was observed in CF mice at baseline. However, CF mice showed reduced response to β-adrenergic stimulation. Myocyte contractility and Ca2+transients were similar between the CF mice and the controls, suggesting that the observed increase in ventricular torsion in CF mice might be due to changes in ventricular structure.

3902.   66 Circular Tagging with Concentric Data Acquisition: Can we go real-time?
Shokoufeh Golshani1, Abbas N Moghaddam1, Holden H Wu2, and J. Paul Finn2
1BME, Tehran Polytechnic, Tehran, Tehran, Iran, 2Radiological Science, UCLA, Los Angeles, CA, United States

In circular tagging, the information of tag lines which is used for strain imaging lies on an annular region in the k-space that can be collected efficiently through concentric sequence in shorter scan times. In this study, we investigate the feasibility of real-time data acquisition for strain imaging through the effective k-space concentric sampling. We showed that by acquisition of a small fraction of the k-space data (approximately 11%), we can still reconstruct the image in an effective way and extract the tag lines information required for strain analysis and this will be very promising for real-time strain imaging.

3903.   67 Regional Myocardial Contractility In Thalassemia Major By Magnetic Resonance Tagging
Antonella Meloni1, Chiara Tudisca2, Emanuele Grassedonio2, Cristina Paci3, Alessandra Quota4, Petra Keilberg1, Vincenzo Positano1, Massimo Midiri2, Massimo Lombardi1, and Alessia Pepe1
1CMR Unit, Fondazione G.Monasterio CNR-Regione Toscana and Institute of Clinical Physiology, Pisa, Italy, 2Policlinico "Paolo Giaccone", Istituto di Radiologia, Palermo, Italy, 3Centro Trasfusionale, Ospedale S Maria alla Gruccia, Montevarchi, Italy, 4Serv. Talassemia, Osp. "V. Emanuele III", Gela, Italy

Compared to healthy subjects, patients with thalassemia major (TM) have a significant lower cardiac contractility, assessed by means of MR tagging techniques. However in TM the altered contractility is not related to cardiac iron, volumes and global function.

3904.   68 Quantify LV rotational mechanics in Duchenne and Becker Muscular Dystrophy using MR tagging
Zhe Wang1,2, Meral L Reyhan2,3, Sarah Kahn2, Pierangelo Renella2,4, J.Paul Finn2,3, Nancy Halnon5, and Daniel B. Ennis1,2
1Department of Bioengineering, University of California, Los Angeles, CA, United States, 2Department of Radiological Science, University of California, Los Angeles, CA, United States, 3Biomedical Physics Interdepartmental Program, University of California, Los Angeles, CA, United States, 4Department of Medicine (Pediatric Cardiology), Children’s Hospital of Orange County, Orange, CA, United States, 5Department of Medicine (Pediatric Cardiology), University of California, Los Angeles, CA, United States

The functional consequences of ventricular fibrosis in pediatric patients with Duchenne or Becker muscular dystrophy (DMD/BMD) are incompletely understood. The objective of this study was to quantify LV rotational mechanics using cardiac MRI tagging and relate it to the presence of fibrosis in pediatric patients with DMD/BMD. Our results indicate that DMD/BMD directly reduces the magnitude of all measures of ventricular rotational mechanics and that the presence of fibrosis in DMD/BMD further reduces their magnitude. EF was preserved in DMD, BMD, and DMD with fibrosis despite abnormality in LV rotational mechanics, which may be early indicators of ventricular dysfunction.

3905.   69 LV hemodynamic performance quantification at basal and mid-ventricular level in mice with heart failure
Magdalena Jablonska1,2, Urszula Tyrankiewicz1, Henryk Figiel2, and Tomasz Skorka1
1Department of Magnetic Resonance Imaging, The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, Poland,2Department of Medical Physics and Biophysics, AGH University of Science and Technology, Krakow, Poland

Considering complex cardiac structure and functional changes during HF, the hypothesis was tested: if the LV basal layer may exhibit diastolic perturbation earlier then mid-ventricular one when assessed using high time-resolved cine MR images (60 movie frames/cardiac cycle). Cardiac function of Tgαq*44 mice with HF was imaged (at 9.4T) and data were analyzed using piecewise linear regression. Mice with HF exhibited altered cardiac relaxation, filling, isovolumic relaxation and contraction time at the basal layer – that was not observed at mid-ventricular one. Obtained data highlighted cardiac regions that may be particularly useful for MRI diagnosis of early stages in HF.

3906.   70 Radial and Circumferential Strain using feature tracking from Cine SSFP Imaging with Compressed Sensing at Rest and with MRI Exercise Ergometry
Christian Hamilton-Craig1,2, Wendy Strugnell1, Qurain Alshammari2,3, Mark Chapman1, Norman Morris4, Helen Seale5, Fiona Kermeen5, Benjamin Schmitt6, Michael Zenge7, Jonathan Chan8, and Andre La Gerche9
1Richard Slaughter Centre of Excellence in CVMRI, The Prince Charles Hospital, Brisbane, Queensland, Australia, 2Centre for Advanced Imaging, University of Queensland, Brisbane, Queensland, Australia, 3College of Applied Medical Science, Hail, Saudi Arabia, 4Griffith Health Institute, Griffith University, Queensland, Australia, 5Heart Lung Institute, The Prince Charles Hospital, Queensland, Australia, 6Imaging & Therapy Systems Division, Siemens Ltd. Australia, NSW, Australia, 7Imaging & Therapy Division, Siemens AG, Erlangen, Germany, 8Heart Research Centre, Griffith University, Queensland, Australia, 9St Vincent's Hospital and University of Melbourne, Victoria, Australia

MRI strain using grid tagging is time consuming to analyze, and is not widely applied for clinical deformation imaging. Recently, MRI strain imaging using post-processing feature tracking on standard SSFP images is a novel technique without need for additional tagging acquisitions. Two elite athletes were imaged at rest and during exercise on a 1.5T system using an MRI pedal ergometer with ultra-fast ECG-triggered cine SSFP imaging and iterative compressed sense reconstruction. Rest and exercise (100 Watts) datasets were analysed with feature tracking for circumferential and radial strain. Myocardial deformation is feasible using feature tracking on ultra-fast cine SSFP image sets.

3907.   71 Reproducibility of Self-Gated Cardiac Functional MRI in Mice @ 11.7T
Volker Rasche1,2, Anne Subgang2, and Alireza Abaei2
1Internal Medicine II, Ulm University, Ulm, BW, Germany, 2Core Facility Small Animal MRI, Ulm University, Ulm, BW, Germany

: The use of self-gated cardiac functional imaging in small animals appears attractive especially since avoiding ECG recordings significantly decreases the required preparation time of the animals. In this contribution the reproducibility of the self-gating approach is investigated. It is shown that a high individual reproducibility can be achieved in repeated scans, if a standardized imaging protocol is used for data acquisition.

3908.   72 Application of breath-hold spiral tissue phase velocity mapping in a DCM patient
Robin Simpson1,2, Jennifer Keegan1,2, and David Firmin1,2
1Imperial College, London, England, United Kingdom, 2Royal Brompton Hospital, London, England, United Kingdom

A novel spiral tissue phase velocity mapping technique has recently been developed and tested in healthy volunteers. Three directional data is acquired in a clinically acceptable breath-hold of just 13 heartbeats. This abstract presents initial experience with scanning a DCM patient and comparing the results with an age-matched volunteer.


Vessel Wall Imaging & Emerging Technologies

Tuesday 13 May 2014
Exhibition Hall  14:30 - 15:30

  Computer #  
3909.   1 Delayed gadolinium enhanced MRI reveals nanotherapy-induced normalization of the vessel wall endothelium in atherosclerotic mice
Claudia Calcagno1, Jun Tang1, Laurien Hassing1,2, Brenda L Sanchez-Gaytan1, Gustav Strijkers1,2, Willem JM Mulder1,2, and Zahi A Fayad1
1Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Amsterdam Medical Center, Amsterdam, The Netherlands, Netherlands

Atherosclerosis is the number one killer world-wide. Increased permeability due to inflammation is a hallmark of vulnerable atherosclerotic plaques, at high-risk of causing myocardial infarction or stroke. This knowledge has spurred interest in developing new compounds to lower plaque inflammation, and non-invasive techniques to quantify their efficacy. Here we examine the effects on vessel wall permeability of a previously developed drug-loaded lipoprotein nanoparticle ([S]-rHDL) with known potent anti-inflammatory effects. We demonstrate that this compound lowers aortic plaque permeability in atherosclerotic ApoE-KO mice, as determined by in vivo Gd-DTPA enhanced MRI, and as validated by ex vivo EB NIRF imaging.

3910.   2 Monitoring of endothelial permeability and plaque progression in a rabbit model of atherothrombosis using an albumin-binding MR contrast agent
Alkystis Phinikaridou1, Marcelo K Andia2, Prakash Saha1, Alberto Smith1, and Rene M Botnar1
1King's College London, London, United Kingdom, 2Pontificia Universidad Catolica de Chile, Santiago, Chile

Endothelial dysfunction, characterized by increased vascular permeability and impaired endothelial-dependent vasodilation, precedes and portends the development of atherosclerosis. MRI studies have shown that impaired focal endothelial dysfunction correlates with the extent of focal plaque burden in the coronary arteries. We have also reported that gadofosveset, an albumin-binding MR contrast agent, can be used to non-invasively assess endothelial permeability, plaque burden progression and regression in a murine model of accelerated atherosclerosis. To expand our previous findings we investigated the interplay between endothelial dysfunction, plaque progression and instability in a bigger animal (rabbit) model of accelerated disease.

3911.   3 3D dynamic contrast enhanced (DCE) MRI of atherosclerotic plaques: image quality, temporal stability and ex vivo validation in a rabbit model
Claudia Calcagno1, Mark E Lobatto1, Philip M Robson1, Olivier Lairez1, Max Senders1, Alexandra Black1, Sarayu Ramachandran1, Willem JM Mulder1,2, Venkatesh Mani1, and Zahi A Fayad1
1Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Amsterdam Medical Center, Amsterdam, The Netherlands, Netherlands

Abundant, permeable microvasculature is a hallmark of high-risk atherosclerotic plaques, and can be quantified using non-invasive 2D dynamic contrast enhanced (DCE) MRI. Current 2D DCE-MRI acquisitions suffer from several limitations. Here we compare 3D turbo field echo (TFE) and turbo spin echo (TSE) DCE-MRI with extensive spatial coverage in atherosclerotic rabbits. We find that 3D TFE DCE-MRI has higher temporal stability than 3D TSE DCE-MRI, and allows for comparable vessel wall/lumen delineation. Furthermore we find that in vivo permeability by 3D TFE DCE-MRI correlates significantly with ex vivo permeability by ex vivo Evans Blue fluorescence.

3912.   4 A Real-IR 3D T1-Weighted Black-Blood Imaging Technique Combining with White-Blood
Tokunori Kimura1 and Kazuhiro Sueoka2
1MRI Systems Development Department, Toshiba Medical Systems corp., Otawara, Tochigi, Japan, 2Software engineering department, Toshiba Medical Systems Engineering corp., Otawara, Tochigi, Japan

We proposed and assessed a new inversion-prepared phase-sensitive 3D black-blood (Real-IR BB) imaging technique combining with white-blood (WB), where the read-out was GRE and the phase correction for BB was performed by using 3D Time-of-Flight (TOF) data. The advantages of our method are the wider slab thickness is available and no requirements for the data only for phase correction. Experiments were performed on 3T MRI for volunteer neck and brain. Optimal TI was regarded as 400-500ms from the views of T1 contrasts among different tissues and the vessel-to-background contrast. We concluded that our proposed 3D Real-IR T1W-BB is a time-efficient vessel-wall imaging method.

3913.   5 Intracranial vessel wall abnormalities in young stroke patients at 7.0 tesla MRI
Nikki Dieleman1, Anja G. van der Kolk1, Susanne J. van Veluw2, Anita A. Harteveld1, Catharina J.M. Frijns2, Peter R. Luijten1, and Jeroen Hendrikse1
1Department of Radiology, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, 2Department of Neurology, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands

Ischemic stroke is relatively rare in young patients, and often not caused by atherosclerosis, but by other, more difficult to diagnose diseases, like intracranial dissections, cardioembolic stroke and vasculitis. In this study, we aimed to demonstrate patterns of vessel wall abnormalities in young stroke patients using 7T intracranial vessel wall MRI. Our results show that in this patient group with heterogeneous causes of ischemic stroke, different patterns of vessel wall abnormalities exist, which may serve as diagnostic marker for the discrimination between the different causes of stroke in young patients.

3914.   6 High quality 7T MRI of atherosclerotic plaque in the significantly stenosed carotid artery
Alexandra A.J. de Rotte1, Wouter Koning2, Martine T.B. Truijman3,4, Anne G. den Hartog5, Sandra M. Bovens6, Aryan Vink7, Shahrzad Sepehrkhouy7, Jaco J.M. Zwanenburg8, Dennis W.J. Klomp8, Gerard Pasterkamp9, Frans L. Moll5, Peter L. Luijten8, Jeroen Hendrikse8, and Gert Jan de Borst5
1Radiology, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, 2University Medical Center Utrecht, Utrecht, Netherlands, 3Radiology and Clinical Neurophysiology, Maastricht University Medical Center, Limburg, Netherlands, 4Cardiovascular Research Institute Maastricht, Limburg, Netherlands,5Vascular Surgery, University Medical Center Utrecht, Utrecht, Netherlands, 6Bioengineering, Imperial College London, London, United Kingdom, 7Pathology, University Medical Center Utrecht, Utrecht, Netherlands, 8Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 9Experimental Cardiology, University Medical Center Utrecht, Utrecht, Netherlands

This is the first study showing the feasibility of carotid plaque imaging at 7T in a series of patients with a symptomatic carotid artery stenosis of >70%. The available BB sequences at 7T seem accurate to demonstrate that an increasing hyperintensity of the MR signal in the carotid plaque on the PDW sequence is inversely proportional to the absence of calcification in the atherosclerotic plaque. Carotid plaque MRI at 7T enables to increase SNR significantly, compared to 3T, which results in accurate luminal and vessel wall determination, both in healthy volunteers and in a series of high-risk patients.

3915.   7 Automatic Intracranial 3D Wall Shear Stress Vessel Segmentation and Localization
Eric Schrauben1,2, Anders Wåhlin2,3, Khalid Ambarki2,4, Jan Malm5, Oliver Wieben1,6, and Anders Eklund2,4
1Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin, United States, 2Radiation Sciences, Umeå University, Umeå, Sweden, 3Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Umeå, Sweden, 4Center for Biomedical Engineering and Physics, Umeå University, Umeå, Sweden, 5Clinical Neuroscience, Umeå University, Umeå, Sweden, 6Radiology, University of Wisconsin - Madison, Madison, Wisconsin, United States

4D flow MRI in conjunction with a novel WSS post-processing method that localizes regions of the vessel wall is developed. It exhibits significant differences in inner versus outer-wall vessel regions in curves as well as differences between healthy young and healthy elderly diastolic WSS in the ICA siphon.

3916.   8 Longitudinal relaxation time and apparent diffusion coefficient in human carotid plaque at 3T: phantom validation and histological comparison
Hideki Ota1, Mika Watanabe2, Tatsuo Nagasaka3, Makoto Obara4, and Hajime Tamura5
1Diagnostic Radiology, Tohoku University Hospital, Sendai, Miyagi, Japan, 2Pathology, Tohoku University Hospital, Sendai, Miyagi, Japan, 3Radiology, Tohoku University Hospital, Sendai, Miyagi, Japan, 4Philips Electronics Japan, Tokyo, Japan, 5Health Sciences, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan

We optimized a 3-dimensional double-angle Look-Locker and outer volume suppression diffusion weighted imaging sequences to quantify longitudinal relaxation rate (R1) and apparent diffusion coefficient (ADC) of human carotid plaque components. We measured R1 and ADC of histologically-confirmed plaque components such as lipid core, hemorrhage and fibrous tissue. Our result indicated that the combination of R1 and ADC enabled objective segmentation of carotid plaque components.

3917.   9 Studying the interplay between atherosclerosis and deep vein thrombosis in a murine model using an elastin-binding contrast agent
Alkystis Phinikaridou1, Prakash Saha1, Marcelo K Andia2, Alberto Smith1, and Rene M Botnar1
1King's College London, London, United Kingdom, 2Pontificia Universidad Catolica de Chile, Santiago, Chile

Venous thrombosis and atherosclerosis are common conditions that together cause significant morbidity and mortality worldwide. Recent evidence suggests that venous thrombosis increases the risk of myocardial infarction and stroke, which persists for many years following the thrombotic event. In the current work, we sought to use an experimental model of atherosclerosis and deep vein thrombosis to investigate the link between plaque growth and venous thrombosis using an elastin-specific MR contrast agent in a longitudinal fashion.

3918.   10 Intraplaque Hemorrhage Detected by High resolution 3D T1-SPACE in Symptomatic Intracranial Atherosclerotic Disease
Qi Yang1, Kuncheng Li1, Yiu-Cho Chung2, Lei Zhang2, Baixue Jia1, Xiaodong Zou3, and Xin Liu2
1Radiology, Xuanwu Hospital, Beijing, Beijing, China, 2Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China, 3Neurology, Xuanwu Hospital, Beijing, Beijing, China

T1-W 3D-SPACE can potentially provide direct visualization of atherosclerotic lesions of the intracranial arteries in patients with acute stroke, and it can detect signal changes suggestive of unstable plaque.

3919.   11 Improved Spatial and Temporal Resolution Black-Blood Dynamic Contrast-Enhanced Carotid Artery Wall MRI Using Compressed Sensing
Zhengwei Zhou1,2, Zhaoyang Fan1, Yibin Xie1,2, Debiao Li1,2, and Behzad Sharif1
1Biomedical Imaging Research Institute, Cedars Sinai Medical Center, Los Angeles, California, United States, 2Department of Bioengineering, University of California, Los Angeles, Los Angeles, California, United States

Dynamic gadolinium contrast-enhanced (DCE) vessel wall imaging has been used to quantitatively assess the inflammatory status of carotid plaques. In this study, compressed sensing was applied to improve the temporal resolution of carotid wall DCE MRI from about 20s to about 8s. With this improvement, SRDIR DCE is promising for quantitative assessment of the inflammatory status of carotid plaques, an important biomarker for the vulnerability of the plaque.

3920.   12 Effect of Rosuvastatin Therapy on the Adventitial Perfusion of Carotid Plaque with Intraplaque Hemorrhage: A Dynamic Contrast-enhanced MR Imaging Study
Jianming Cai1, Bao Cui1, Ruixue Du2, Lu Ma1, Xu Han1, Youquan Cai1, Xin Lou1, Lin Ma1, and Ping Ye2
1Department of Radiology, Chinese PLA General Hospital, Beijing, China, 2Department of Geriatric Cardiology, Chinese PLA General Hospital, Beijing, China

Evaluation of effects of lipid-lowering therapy on atherosclerotic plaques with IPH should be focused on inflammatory activity rather than composition and plaque burden. IPH may be irreversible content within the first one year after treatment. Kinetic parameters of DCE-MRI has the most possibility to become the valuable biomarker in vivo, noninvasively.

3921.   13 High Resolution Cine of the Heart at 3T with Free Breathing Cine-GRICS
Pierre-André Vuissoz1,2, Freddy Odille1,2, Christophe Meyer1,2, Laurent Bonnemains3,4, Damien Mandry1,4, and Jacques Felblinger1,3
1Imagerie Adaptative Diagnostique et Interventionnelle, Université de Lorraine, Nancy, France, 2U947, INSERM, Nancy, France, 3CIT801, INSERM, Nancy, France, 4University Hospital Nancy, Nancy, France

Valves and coronary vessels remain difficult to observe in low resolution dynamic cine MR images. High resolution cardiac cine MRI implies a long acquisition time requiring free breathing which leads to breathing motion artifacts. Cine-GRICS reconstructs motion compensated images using physiological sensors. On six volunteers, series of 5mm thickness 384x384 free breathing cine images covering the heart in anatomical orientations have been acquired at 3T. Despite contrast change due to long TR in high resolution SSFP, expected anatomical details could be observed. A high resolution protocol covering the heart with cine images was performed in less than one hour.

3922.   14 Inter-rater and Intra-rater Reliability of cineFSE Carotid Measurements
Mari Elyse Boesen1,2, Alexandra Pulwicki2,3, Luis Alberto Souto Maior2,4, Jerome Yerly2,5, Robert Marc Lebel2,6, and Richard Frayne2,7
1Biomedical Engineering, University of Calgary, Calgary, AB, Canada, 2Seaman Family MR Research Centre, Calgary, AB, Canada, 3Physics & Astronomy, University of Calgary, AB, Canada, 4Universidade Federal de Campina Grande, PB, Brazil, 5CardioVascular MR Research Center, Centre d'Imagerie BioMedicale, Lausanne, Switzerland, 6Applied Sciences Laboratory, GE Healthcare, AB, Canada, 7Radiology & Clinical Neuroscience, Hotchkiss Brain Institute, University of Calgary, AB, Canada

The inter-rater and intra-rater reliability of three cardiac gated carotid imaging techniques (cineFSE, prospectively gated FSE, and cineGRE) were determined by comparison of repeated manual tracings of common carotid area in ten healthy subjects. All sequences reflected highly repeatable manual measures (inter-rater ICC ≥ 0.85 in all cases). Minimum detectable difference (MDD) was calculated for each sequence to determine its ability to characterize changes in carotid distension. The cineFSE images produced the lowest MDD (5.8 mm2) compared to prospective FSE (7.4 mm2) and cineGRE (7.8 mm2). Additionally, the scan-rescan reliability of the cineFSE technique was assessed.

3923.   15 Optimal Sequence Weighting for 3D Dynamic Contrast Enhanced Imaging
Philip M Robson1, Claudia Calcagno1, Sarayu Ramachandran1, Mark E Lobatto1, Julia Witjes1, Venkatesh Mani1, and Zahi A Fayad1
1Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States

Three dimensional (3D) evaluation of atherosclerotic plaque is important for investigating vascular disease. Dynamic contrast enhanced (DCE) imaging is able to measure the abundant microvasculature in vulnerable plaque. However, it is challenging to achieve 3D coverage and adequate temporal resolution, therefore, it is important to optimize the available signal. Here, we compare the signal weighting and contrast to noise ratio of gradient-echo and spin-echo based 3D acquisition sequences in a phantom and assess image quality pre and post contrast agent administration in an atherosclerotic rabbit model. The optimal sequence was a turbo field echo acquisition with strong T1-weighting.

3924.   16 Single breath-hold 3D cardiac T1 mapping
Yong Chen1, Haris Saybasili2, Alice Yang3, Katherine L Wright3, Mark A Griswold1,3, Vikas Gulani1,3, and Nicole Seiberlich3
1Radiology, Case Western Reserve University, Cleveland, OH, United States, 2Siemens Healthcare, Chicago, Illinois, United States, 3Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States

Fast, accurate measurement of T1 relaxation times over the whole heart is challenging due to physiologic cardiac and respiratory motion. Here a high-resolution 3D cardiac T1 mapping technique is presented which uses the modified Look-Locker method, a stack-of-spirals trajectory and through-time non-Cartesian GRAPPA acceleration in combination with GPU image reconstruction. This proposed technique allows fast T1 mapping of the whole heart in 12 heart beats and fast image reconstruction suitable for real clinical applications.

3925.   17 3D Free-breathing, CINE Magnetization Transfer Imaging for assessment of Whole-heart function and Great Vessels
Eric Schrauben1, Christopher François2, Oliver Wieben1,2, and Kevin Johnson1
1Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin, United States, 2Radiology, University of Wisconsin - Madison, Madison, Wisconsin, United States

We evaluate an MT-prepared free-breathing 3D radial SPGR functional cardiac sequence in-vivo and compare to 2D Cartesian and 3D T2-prep sequences.

3926.   18 A new transducer-free MR elastography method for voxel-based mapping of aortic stiffness in vivo
Rachel Clough1, Jordi Alastruey1, Abdelali Ghazouani1, Louis Vilgrain1, Simon Lambert1,2, and Ralph Sinkus1
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, London, United Kingdom, 2Centre for Inflammation Research, INSERM U1149, Clichy, Ile de France, France

Aortic stiffness is one of the most important risk factors in the development of cardiovascular disease. Magnetic resonance elastography (MRE) using an external mechanical transducer has previously been used to non-invasively assess the viscoelastic properties of soft tissue by imaging the propagation of shear waves in tissue. Here we develop a free-breathing MRE sequence using shear waves generated by the aortic valve closure (an intrinsic source of mechanical waves) to assess aortic elasticity in vivo. Volunteer studies show a clinically acceptable acquisition time (1:39(min:sec)), and good correlation between MRE and pulse wave velocity (the reference-standard) (bias=-0.26m/s).

3927.   19 Combination of a 13C cryoprobe with hyperpolarization allows real time observation of pyruvate carboxylation in the perfused mouse heart
Colin Purmal1, Blanka Kucejova1, Shawn Burgess1, Craig Malloy1, Dean Sherry1, and Matthew E Merritt1
1AIRC, UTSW Medical Center, Dallas, TX, United States

Murine models of myocardial metabolism are a pervasive tool used by the cardiovascular research community. Development of methods for monitoring energy metabolism in the perfused mouse heart would augment the understanding of a variety of myocardial pathologies and dysfunctions. Here, hyperpolarized pyruvate is combined with a 13C optimized cryogenic probe to produce an approximate sensitivity gain of 140,000x for carbon spectroscopy. The resulting spectra in the functioning heart allow pyruvate carboxylation to be monitored in real time, a pathway accepted to have a relative activity of about 5 % of that of pyruvate dehydrogenase.

3928.   20 Rapid Real-Time Cardiac MRI Exploiting Synchronized Cardio-Respiratory Sparsity
Li Feng1, Leon Axel1, Jian Xu2, Daniel K Sodickson1, and Ricardo Otazo1
1Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University, School of Medicine, New York, New York, United States, 2Siemens Medical Solutions, New York, New York, United States

A novel approach for cardiac MRI reconstruction is proposed, which can overcome some limitations in conventional technique and provide new kinds of functional information. Specifically, we acquire cardiac data continuously using golden-angle radial trajectories and detect both cardiac and respiratory signals from the data itself. The data can be retrospectively sorted during the image reconstruction into an expanded set of images, spanning different phases of both cardiac and respiratory cycles. The increased dimensionality enables high quality free breathing imaging using compressed sensing and allows investigation of the interactions between cardiac and respiratory cycles in their effects on cardiac function.

3929.   21 Cardiac Function Analysis in Multi-cycle Real-time MRI
Teodora Chitiboi1,2, Anja Hennemuth1, Lennart Tautz1, Markus Hüllebrand1, Jens Frahm3, and Horst Hahn1
1Fraunhofer MEVIS, Bremen, Bremen, Germany, 2Jacobs University, Bremen, Bremen, Germany, 3Max Planck Institute for Biophysical Chemistry, Göttingen, Germany

The recent development of a real-time magnetic resonance imaging (MRI) technique with 20 to 30 ms temporal resolution allows for imaging multiple consecutive heart cycles, without the need for breath holding or ECG synchronization. Manual analysis of the resulting image series is no longer feasible because of their length. We propose a region-based algorithm for automatically segmenting the myocardium in consecutive heart cycles based on local context and prior knowledge. The method was evaluated on ten real-time MRI series and compared to segmentations by two observers, with promising results. We show that our approach enables a multicycle analysis of the heart function robust to breathing and arrhythmia.

3930.   22 In vivo MR imaging of zebrafish with focus on cardiac tissue
Ilse van Herck1, Andor Veltien1, Juan Manuel González-Rosa2, Erik de Vrieze3, Gert Flik3, Nadia Mercader2, and Arend Heerschap1
1Radiology, Radboudumc, Nijmegen, Netherlands, 2Cardiovascular development and repair, CNIC, Madrid, Spain, 3Organismal animal physiology, Radboud University Nijmegen, Nijmegen, Netherlands

Zebrafish have become popular models to study disease conditions such as myocardial infarctions. For cardiac investigations it is important that heart function can be assessed by live imaging, but this is challenging in adult zebrafish. We developed an experimental setup that allowed to acquire MRI of live zebrafish with limited motion artifacts and an in-plane resolution of 25x25 µm. In addition we obtained in vivo cardiac MR images of the zebrafish heart using the IntraGate brightblood Cine FLASH sequence.

3931.   23 Radiation-induced myocardial injury visualized by LGE-MRI
Brent D. Wilson1,2, Alexis Harrison1,2, Yu-Huei J. Huang3, Kavitha Damal2, Nathan S. Burgon2, Mark M. Haslam2, Martha J. Glenn3, David K. Gaffney3, Bill J. Salter3, Nassir F. Marrouche1,2, and Christopher J. McGann1,2
1Cardiovascular Center, University of Utah, Salt Lake City, Utah, United States, 2Comprehensive Arrhythmia Research and Management Center, University of Utah, Salt Lake City, Utah, United States, 3Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah, United States

Recent advances in LGE-MRI technology allow us to visualize and quantify the extent of myocardial tissue injury after external beam radiation therapy (EBRT) for treatment of cancer. We evaluated the utility of 3D late gadolinium enhanced MRI to identify atrial injury secondary to EBRT and the correlation between extent of tissue damage and dose of EBRT administered. Cardiac MRI identifies subclinical injury months after EBRT and also shows a dose-dependent pattern of injury. Imaging myocardial injury resulting from radiation using MRI may be a useful modality to follow cardiac toxicity from EBRT and identify individuals who are more susceptible to CV radiation damage.

3932.   24 Compartmentation in the Myocardium: On the Fate of Exogenous Versus Glycolytically Derived Pyruvate
Colin Purmal1, Blanka Kucejova1, Shawn Burgess1, Craig Malloy1, Dean Sherry1, and Matthew E Merritt1
1AIRC, UTSW Medical Center, Dallas, TX, United States

Depending upon the underlying energetic demands for ATP production in the myocardium, pyruvate has multiple metabolic fates: exchanging with alanine or lactate, being oxidized via the pyruvate dehydrogenase (PDH) complex, or carboxylated to form oxaloacetate. Here the metabolism of exogenous hyperpolarized [1-13C]pyruvate is compared with that of glucose in the perfused mouse heart. A battery of analyses indicate that 1)exogenous pyruvate oxidation and glucose oxidation are not synonymous, 2)hyperpolarized lactate production does not necessarily report on [lactate] in the heart, and 3) propionate activated PDH flux even in the presence of a short chain fatty acid. The simplest interpretation of these phenomena requires a two compartment model of myocardial metabolism.


Emerging Techniques & Image Processing

Tuesday 13 May 2014
Exhibition Hall  14:30 - 15:30

  Computer #  
3933.   25 Ungated Cardiac-Phase-Resolved First-Pass MRI for Concurrent Imaging of Myocardial Function and Perfusion at Peak Stress
Behzad Sharif1, Reza Arsanjani1, Rohan Dharmakumar1, Noel Bairey Merz1, Daniel S Berman1, and Debiao Li1
1Biomedical Imaging Research Institute, Dept. of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, United States

The purpose of this work is to propose an accelerated cardiac-phase-resolved myocardial first-pass perfusion imaging technique. Using ungated continuous acquisition, the proposed method is capable of generating "cine" myocardial perfusion images thereby enabling concurrent imaging of wall motion and perfusion deficits.

3934.   26 Myocardial perfusion imaging with an interleaved multi-slice acquisition for steady-state readout without saturation preparation or gating
Haonan Wang1, Neal Kepler Bangerter1,2, Ganesh Adluru2, Meredith Ireene Taylor1, and Edward V.R DiBella2
1Department of Electrical & Computer Engineering, Brigham Young University, Provo, UT, United States, 2Utah Center for Advanced Imaging Research, University of Utah, UT, United States

First-pass myocardial perfusion imaging is a powerful method for characterizing ischemic heart disease. Standard methods use saturation preparation and an ECG trigger. A new ungated acquisition with no saturation preparation could be used to acquire steady-state spoiled gradient echo (SPGR) images. Here, readouts from multiple (three) slices are interleaved in order to keep the multiple slices at steady-state and increase the effective TR. Simulations, phantoms, and human data are used to compare the interleaved acquisition to a conventional saturation recovery sequence both in radial and Cartesian trajectories.

3935.   27 Method for Correcting Respiratory Artefacts in Parallel-Accelerated First-Pass Myocardial Perfusion Imaging
Merlin Fair1,2, Peter D Gatehouse1,2, Peter Drivas1, Francisco Alpendurada1, and David N Firmin1,2
1NIHR Cardiovascular BRU, Royal Brompton Hospital, London, United Kingdom, 2NHLI, Imperial College, London, United Kingdom

A method is presented for the correction of potential respiratory aliasing artefacts in accelerated myocardial perfusion imaging (MPI) reconstructions during free-breathing; as liable to occur during stress imaging at high parallel imaging acceleration factors. A multiple free-breathing prescans (MFP) technique gives an extended range of coil sensitivity information throughout the respiratory cycle, allowing improvements in the accuracy of parallel imaging reconstructions through selection of appropriate reference data. Applicable to single-shot dynamic acquisition series, the MFP method is shown to reduce aliasing artefacts as caused by hyperpnoea in MPI in comparison to standard parallel imaging methods.

3936.   28 Non-ECG-Triggered Perfusion Imaging with Integrated T1 Mapping for Quantifying Myocardial Blood Flow
David Chen1,2, Behzad Sharif1, Janet Wei1, Reza Arsanjani1, Louise EJ Thomson3, C. Noel Bairey Merz1, Daniel S Berman3, and Debiao Li3
1Cedars Sinai Medical Center, Los Angeles, CA, United States, 2Biomedical Engineering, Northwestern University, Evanston, IL, United States, 3Cedars Sinai Medical Center, Los Angeles, California, United States

Propose a non-ECG-triggered acquisition with cardiac motion self-triggering for integrated T1 derived AIF for MBF quantification. This method may improve robustness to cardiac motion and clinical reliabillity of quantitative myocardial perfusion imaging.

3937.   29 Free-breathing Myocardial Perfusion Imaging using Respiratory Binning
Johannes F. M. Schmidt1, Lukas Wissmann1, and Sebastian Kozerke1,2
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom

Respiratory motion artifacts in free-breathing myocardial perfusion imaging can be suppressed by sorting of k-space data into respiratory bins and individual reconstruction for each respiratory state.

Xue Feng1, Yang Yang1, David Lopez2, Michael Salerno2,3, and Craig H Meyer1,3
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, 2Medicine, University of Virginia, Charlottesville, VA, United States,3Radiology, University of Virginia, Charlottesville, VA, United States

Myocardial first-pass perfusion imaging is a promising diagnostic tool for the assessment of ischemic heart disease. Most studies utilize a saturation recovery (SR) preparation for T1 weighting and a spoiled GRE readout module. Spiral imaging, due to its high acquisition speed and robustness against motion artifacts, has been successfully adopted in this application combined with the SR GRE sequence using the traditional spiral-out trajectory. SR combined with a transient SSFP readout is an alternative sequence that can provide higher SNR. The spiral-in/out bSSFP sequence is advantageous over the traditional spiral-out bSSFP sequence since it can take advantage of the refocusing mechanism at TE = TR/2 to increase SNR and automatically achieve first gradient moment nulling due to the symmetry. In this study we will combine the spiral-in/out trajectory with the SR SSFP sequence and acquire perfusion data in the transient phase.

3939.   31 A robust automated multi-modality registration tool applied to abdominal aortic aneurysm
Chengjia Wang1,2, Georgia Koutraki1,3, Olivia Mcbride3, Alex Vesey3, Tom MacGillivray1, Calum Gray1, David Newby1,3, Keith Goatman2, and Scott Semple1,3
1Clinical Research Imaging Centre, University of Edinburgh, Edinburgh, United Kingdom, 2Toshiba Medical Visualization System-Europe, Edinburgh, United Kingdom, 3Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom

Combining multi-modality data is a challenging but important step in the development of non-invasive assessment of cardiovascular disease. We present a semi-automatic scheme for inter-parameter and inter-modality registration of aortic MR and CT data, requiring only simple interactions. The algorithm was evaluated in a clinical trial investigating the diagnosis and treatment of abdominal aortic aneurysms, using a novel imaging protocol. Image alignment was compared with manual registration performed by experienced observers and mostly displayed sub-pixel accuracy. Integration of non-rigid registration will be convenient and this method will be applied to cardiac MR data in the future.

Azza S. Hassanein1, Ayman M. Khalifa1, Brian P. Shapiro2, and El-Sayed H. Ibrahim2
1Helwan University, Cairo, Egypt, 2Mayo Clinic, Jacksonville, Florida, United States

Delayed-hyperenhancement(DHE) MRI provides a viability image at single heartphase. Obtaining cine DHE images, however, would allow for evaluating both viability and wall motion information from a single set of images, which could be useful for measuring myocardial contractility and for treatment prognosis. However, obtaining cine viability images requires repeatedly playing the DHE sequence with different trigger delays, which increases scan-time. In this study, we propose a new technique for generating cine viability images without additional scan-time. The technique is based on measuring myocardial motion field from the tagged images, which is used to generate DHE images throughout the cardiac cycle.

3941.   33 Improved Detection of Phase Unwrapping Errors in 3D Tagged Cardiac Magnetic Resonance Imaging Data
Ming Li1,2, Himanshu Gupta3, Steven G. Lloyd3, Louis J. Dell'Italia3, and Thomas S. Denney Jr1,2
1AU MRI Research Center, Auburn University, Auburn, AL, United States, 2Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, United States, 3Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL, United States

Phase unwrapping techniques have been proposed to reconstruct 3D+time strain for tagged cardiac magnetic resonance imaging. In recent research, automatically placed branch cuts were used to resolve phase inconsistencies. An algorithm based on the phase difference between pixels was adopted to detect images where the automated branch cuts failed and manual inspection and correction was required. In this abstract, we propose a method for detecting phase unwrapping errors based on spatial smoothness of the unwrapped phase image, which improved the detection and false positive rate compared to the phase difference method and resulted in more accurate strain and torsion measurements.

3942.   34 3D Fractal Analysis of Pulmonary MRA distinguishes Pulmonary Arterial Hypertension Patients from Normal Volunteers
Phillip Kilgas1, Eric Schrauben2, Alejandro Roldan-Alzate1, Oliver Wieben2, Naomi Chesler3, Christopher François1, and Mark L. Schiebler1
1Radiology, UW-Madison, Madison, WI, United States, 2Medical Physics, UW-Madison, Madison, WI, United States, 3Biomedical Engineering, UW-Madison, Madison, WI, United States

Pulmonary arterial hypertension (PAH) is a rapidly progressive disease. As a result of elevated pulmonary arterial pressures, pruning of the number of small pulmonary artery occurs [1]. Quantification of this pruning may provide a biomarker independent of vessel size for this disease and could lessen the need for invasive catheter based measurements. We have found that 3D fractal analysis of the pulmonary arterial branching pattern, derived from MRA examinations, is an independent variable that can be used to diagnose the presence of pulmonary arterial hypertension.

3943.   35 Aberrant Myocardial Sheetlet Orientation in Hypertrophic Cardiomyopathy detected using In Vivo Cardiovascular Magnetic Resonance Diffusion Tensor Imaging
Pedro Ferreira1, Philip Kilner2, Laura-Ann McGill1, Sonia Nielles-Vallespin3, Andrew Scott1, Bruce Spottiswoode4, Xiaodong Zhong5, Siew Ho6, Karen McCarthy6, Tevfik Ismail1, Peter Gatehouse1, Ranil de Silva2, Alexander Lyon1, Sanjay Prasad2, David Firmim2, and Dudley Pennell1
1NIHR cardiovascular BRU, Royal Brompton Hospital, London, London, United Kingdom, 2Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, London, United Kingdom, 3National Institutes of Health, MD, United States, 4Siemens Healthcare, IL, United States, 5Siemens Healthcare, GA, United States, 6Royal Brompton Hospital, London, United Kingdom

Cardiac Diffusion Tensor Imaging (cDTI) provides information on cross-myocyte components of intramyocardial water diffusion with the secondary-eigenvector (E2). Assuming these to be constrained by the sheetlet and shear-layer microstructure of left ventricular myocardium, we investigated if in vivo cDTI could identify changing sheetlet orientations and abnormalities in hypertrophic cardiomyopathy (HCM). We also investigated the impact of myocardial strain correction on the measured sheetlets orientation. Myocardial strain correction results in substantial changes in the orientation of E2. Nevertheless, with or without strain correction, E2 is more wall-perpendicular in HCM, which is in keeping with the sheetlet orientation expected in hyper-contracted myocardium.

3944.   36 Synthetic LGE Derived from Cardiac T1 Mapping for Simultaneous Assessment of Focal and Diffuse Cardiac Fibrosis
Kyungpyo Hong1,2, Edward VR. DiBella1, Eugene G. Kholmovski1, Ravi Ranjan3, Christopher J. McGann3, and Daniel Kim1
1UCAIR, Department of Radiology, University of Utah, Salt Lake City, Utah, United States, 2Department of Bioengineering, University of Utah, Salt Lake City, Utah, United States, 3CARMA, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, United States

While late-gadolinium-enhanced (LGE) MRI is the gold standard for detection of focal myocardial scarring, it is less effective than cardiac T1 mapping for assessment of diffuse fibrosis. We sought to derive synthetic LGE images from saturation-recovery based cardiac T1 maps for simultaneous assessment of focal and diffuse cardiac fibrosis. In 21 short-axis planes with different myocardial lesions created by RF ablation, standard and synthetic LGE images showed similar image quality and signal contrast ratio of the lesion-myocardium and blood-myocardium pairs. The new approach provides a means to simultaneously assess focal and diffuse cardiac fibrosis using cardiac T1 mapping alone.

3945.   37 An efficient algorithm for volumetric measurement of left ventricle using real time cines
Yin Wu1,2, Yinzhu Gao1,2, Ke Jiang1,2, Yucheng Chen3, and Yiu-Cho Chung1,2
1Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Key Laboratory for MRI, Shenzhen Institutes of Advanced Technology, Shenzhen, Guangdong, China, 2Key Laboratory of Health Informatics, Chinese Academy of Sciences, Shenzhen, Guangdong, China, 3Cardiology Department, West China Hospital, Sichuan University, Chengdu, Sichuan, China

Real-time free-breathing cine imaging is highly desirable in cardiac patients for LV function quantification. However, volumetric measurement is prone to be erroneous due to respiratory motion. In this study, we proposed an efficient approach to identify ED and ES phases at end-expiration semi-automatically. Twelve healthy volunteers were scanned using the real-time cine imaging and processed with the proposed method with the standard breath-hold cines as reference. Results showed that the measured LV function was comparable between the two imaging protocols, suggesting the proposed method to be efficient and reliable in analyzing real-time cines.

3946.   38 Ventricular-Function Assessment with Online Post-Processing of Real-time Free-Breathing Radial GRAPPA images
Haris Saybasili1, Gary McNeal1, Michaela Schmidt2, Peter Kellman3, Mark Griswold4, Michael Zenge2, and Nicole Seiberlich5
1Siemens Healthcare USA, Inc., Chicago, Illinois, United States, 2Siemens AG Healthcare Sector, Erlangen, Germany, 3National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States, 4Radiology, Case Western Reserve University, Cleveland, Ohio, United States,5Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States

Radial GRAPPA is well suited for real-time free-breathing cardiac imaging due to its high temporal/spatial resolution. However, the heart-rate variations during real-time acquisitions cause inconsistent number of phases per slice/heart beat. Hence, an off-line post-processing step is often required prior to cardiac function analysis. We developed an online reconstruction module capable of generating a predefined number of phases per slice/heart beat by interpolating real-time images. This module was integrated into radial GRAPPA reconstruction pipeline without code modifications. Healthy volunteer data were acquired and analyzed to compare cardiac function parameters calculated from automatically processed real-time images to the results from segmented cine images.

3947.   39 Super-resolution reconstruction of 4D neonatal cardiac MRI using coupled dictionary learning
Kanwal K Bhatia1, Anthony N Price2, David Cox2, Alan M Groves2, Jo V Hajnal2, and Daniel Rueckert1
1Biomedical Image Analysis Group, Imperial College London, London, London, United Kingdom, 2Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom

We present a novel method for image enhancement of 4D neonatal cardiac MRI using example-based super-resolution reconstruction. Anisotropic, orthogonal cine stacks are acquired covering the cardiac volume. By considering small image patches within these acquisitions, we are able to exploit the inherent redundancy of these data. These are used to learn coupled dictionaries of corresponding high-resolution and low-resolution patches. These dictionaries are then used to upsample the low-resolution view of the acquired stack to isotropic. We apply the algorithm to super-resolve 4D images from six neonates showing improvement over standard bicubic interpolation.

3948.   40 Evaluation of an optimized post-processing tool for 4D flow MRI data analysis in healthy volunteers and patients with aortic stenosis, aortic insufficiency, and aortic aneurysm
Edouard Michel Semaan1, Maria Carr1, Mehmet Gulsun2, Pim van Ooij1, Aurelien Stalder3, James Carr1, Jeremy Collins1, Michael Markl1,4, and Bruce Spottiswoode5
1Radiology Department, Feinberg School of Medicine Northwestern University, Chicago, Illinois, United States, 2Siemens Corporation, Corporate Technology, New Jersey, United States, 3Siemens AG Healthcare Sector, Erlangen, Germany, 4Department of Biomedical Engineering, McCormick School of Engineering, Chicago, Illinois, United States, 5Cardiovascular MR R&D, Siemens Healthcare, Chicago, Illinois, United States

A principle limitations to the clinical utility of 4D flow MR imaging is the lengthy post-processing times required for data analysis. 4D flow datasets are typically post-processed using proprietary lab-specific software. Recently, a novel 4D flow MRI post-processing tool optimized for the evaluation of the thoracic aorta. The purpose of this study was to evaluate this novel 4D flow tool to assess thoracic aortic hemodynamics in healthy volunteers as well as patients with aortic aneurysm and aortic valve disease. The 4D flow tool enabled efficient processing of raw reconstructed 4D flow MRI data, demonstrating significant differences hemodynamics between groups.

3949.   41 Multimodality Tissue Tracking Algorithm of Myocardial Strain: Initial Validation with Tagged MRI
Fabio S Raman1, Michael Tee1,2, Davis Vigneault1,2, Songtao Liu1, and David A Bluemke1,3
1Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD, United States, 2Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Headington, Oxford, United Kingdom, 3Molecular Biomedical Imaging Laboratory, National Institute of Biomedical Imaging and Bioengineering, Bethesda, MD, United States

Left ventricular strain is a potentially beneficial biomarker for regional myocardial function, necessitating methods for its quantification. Traditional CMR tagging techniques used to obtain strain information, including complementary spatial modulation of magnetization (CSPAMM) and displacement encoding with stimulated echoes (DENSE), require dedicated acquisition sequences with low signal to noise ratio and lengthy post-processing times. In this study, we present a novel Multimodality Tissue Tracking (MTT) algorithm that allows for rapid evaluation of MR cine images. The purpose of this study was to validate the MTT software in the assessment of regional myocardial function in a pool of heart failure and healthy volunteers.

3950.   42 Correlation between Cine-derived Strain and Late Gadolinium Enhancement in the Left Atrium
Dana C Peters1, Emma Alexander1, James S Duncan1, Xenophon Papademetris1, Daniel Cornfeld1, Albert J Sinusas2, and Sudhakar Chelikani1
1Diagnostic Radiology, Yale University, New Haven, CT, United States, 2Cardiology, Yale University, New Haven, CT, United States

Abnormal left atrial (LA) strain is a potential cause of LA fibrosis, and the presence of fibrosis will impact LA strain. We have developed a feature tracking method, and applied it to 2-chamber cine images of patients to estimate left atrial strain, and to correlate strain with late gadolinium enhancement estimations of LA fibrosis. Preliminary correlation in 9 patients shows a trend towards lower strain in patients with greater fibrosis.

3951.   43 The pant leg area sum index: New pulmonary MRA metric for the determination of Pulmonary arterial Hypertension
Phillip Kilgas1, Alejandro Roldan-Alzate1, Eric Schrauben2, Naomi Chesler3, Christopher François1, and Mark L. Schiebler1
1Radiology, UW-Madison, Madison, Wisconsin, United States, 2Medical Physics, UW-Madison, WI, United States, 3Bioengineering, UW-Madison, Madison, WI, United States

We sought to determine the utility of a new metric, pant leg volume, derived from the sum of the pulmonary trunk and proximal portions of the right and left pulmonary arteries for the non invasive determination of pulmonary artery hypertension. We found that the non indexed measurements of pant leg volume had the most significant t test value for the determination of elevated pulmonary arterial pressures.

3952.   44 Prognostic CMR parameters for heart failure and arrhythmias in large cohort of well treated thalassemia major patients
Antonella Meloni1, Vincenzo Positano1, Giuseppe Rossi2, Petra Keilberg1, Silvia Macchi3, Antonella Carollo4, Valentina Vinci5, Paolo Preziosi6, Cristina Salvatori1, Massimo Lombardi1, and Alessia Pepe1
1CMR Unit, Fondazione G.Monasterio CNR-Regione Toscana and Institute of Clinical Physiology, Pisa, Italy, 2Epidemiology and Biostatistics Unit, Institute of Clinical Physiology, CNR, Pisa, Italy, 3Servizio Trasfusionale, Ospedale Santa Maria delle Croci, Ravenna, Italy, 4Servizio Talassemia-U.O. Pediatria Talassemia, Az. Osp. "Sant'Antonio abate", Trapani, Italy, 5Istituto di Radiologia, Az. Osp. "Garibaldi" Presidio Ospedaliero Nesima, Catania, Italy, 6U.O.C. Diagnostica per Immagini e Interventistica, Policlinico “Casilino", Roma, Italy

This study aimed to determine the predictive value of CMR parameters for heart failure and arrhythmias in thalassemia major. Thanks to a MR-guided, patient-specific adjustment of the chelation therapy, few cardiac events were detected. Severe and homogeneous MIO, myocardial fibrosis and ventricular dysfunction identify patients at high risk of heart failure. Heart T2* doesn’t have any power in predicting arrhythmias while male sex and atrial dilation are independent prognosticators.

3953.   45 Effect of main pulmonary artery dilation and stiffness on right ventricular volume overload and function in patients with repaired tetralogy of Fallot
Liang Zhong1, Adeline Phang1, Xiaodan Zhao1, Jule Tan1, and Rusan Tan1
1National Heart Centre Singapore, Singapore, Singapore, Singapore

Survivors of Tetralogy of Fallot (TOF) constitute a large and growing population of patients. Although post-surgical outcome is generally favorable, as these patients move into adulthood, late morbidity is becoming more prevalent. Recent evidence suggests that adverse long-term post-surgical outcome is related to chronic pulmonary regurgitation (PR) and RV dilation. Repeat surgery with pulmonary valve replacement (PVR) may be necessary to preempt RV functional deterioration and malignant ventricular arrhythmias. However, optimal time of PVR is still debatable. We speculate that main pulmonary artery area and stiffness are associated with RV dilation and impaired function and might contribute to the referral of PVR.

3954.   46 Non-contrast MRI characterization of thrombus composition and susceptibility to thrombolysis in a mouse model of deep vein thrombosis.
Marcelo E Andia1, Alkystis Phininkaridou2, Prakash Saha3, Bijan Modarai3, Alberto Smith3, and Rene M Botnar2
1Radiology Deparment, Pontificia Universidad Catolica de Chile, Santiago, Santiago, Chile, 2Division of Imaging Sciences and Biomedical Engineering, Kings College London, London, United Kingdom, 3Academic Department of Surgery, Kings College London, London, United Kingdom

In vivo evaluation of the stage of organization of venous thrombosis could help guide medical treatment and intervention. We have previously demonstrated that magnetization transfer ratio (MTR), T1 mapping and apparent diffusion coefficient (ADC) sequences detect the concentration and spatial distribution of collagen and methemoglobin, and proton diffusivity of the thrombus, respectively. In this work we studied if these MR parameters could improve the identification of thrombus suitable for thrombolytic treatment.

3955.   47 Efficient Cardiac MR Gating with Silicon ECG Holder
Nanda Deepa Thimmappa1, Mitchell A Cooper1, Silvina P Dutruel1, Keigo Kawaji1, Thanh D Nguyen1, and Jonathan W Weinsaft1,2
1Radiology, Weill Cornell Medical College, New York, NY, United States, 2Cardiology, Weill Cornell Medical College, New York, NY, United States

Robust and comfortable ECG gating with this reusable silicon lead holder has the potential to revolutionize cardiac gated MRI by eliminating uncomfortable disposable adhesive ECG leads.


Myocardial Tissue Characterization

Tuesday 13 May 2014
Exhibition Hall  14:30 - 15:30

  Computer #  
3956.   49 T1-weighted DCE-MRI may be used to visualize different components of RF ablation injury in the myocardium
Sathya Vijayakumar1,2, Ravi Ranjan2, Nassir F Marrouche2, and Eugene G Kholmovski2,3
1Surgical Services Clinical Program, Intermountain Healthcare, Salt Lake City, Utah, United States, 2CARMA Center, University of Utah, Salt Lake City, Utah, United States, 3UCAIR, Radiology, University of Utah, Salt Lake City, Utah, United States

Radiofrequency (RF) ablation of the left ventricle (LV) and left atrium (LA) are clinically acceptable therapies for ventricular tachycardia (VT) and atrial fibrillation (AF) [1,2]. To the best of our knowledge, there is still a lack of good understanding of acute cardiac lesion physiology. It has been shown earlier that serial late gadolinium enhancement (LGE) imaging of immediately post-ablation atrial lesions can help differentiate between transient and permanent injuries based on time course of lesion enhancement [3]. However, the characterization of different tissue types immediately following an RF ablation procedure has never been addressed. In this work, we use the contrast kinetics of myocardial tissues to identify and differentiate between the various regions of ablated tissue.

3957.   50 3D LGE imaging of the LV short axis stack using spiral readouts at 3T
Iain T Pierce1,2, Jennifer Keegan1,2, Peter Drivas2, and David Firmin1,2
1NHLI, Imperial College London, London, United Kingdom, 2Cardiovascular BRU, Royal Brompton Hospital, London, United Kingdom

A comparison of a free-breathing, 3D stack of spirals acquisition with a conventional breath-hold 2D Cartesian acquisition for late gadolinium enhancement imaging of the left ventricle at 3T. Spiral imaging allowed increased spatial resolution while shortening the data acquisition window and total acquisition duration compared with an equivalent stack of 2D images. Image quality achieved was similar with increased LV blood pool SNR and similar blood / myocardium CNR on spiral images.

3958.   51 Area at risk identified by T2 mapping is influenced by the severity of the initial ischemic insult in acute myocardial infarction
Nilesh R Ghugre1,2, Reuben Thomas3,4, Kevin Thai1, Jennifer Barry1, Beiping Qiang3, Bradley H Strauss3,5, and Graham A Wright1,6
1Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada, 2Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, 3Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada, 4Department of Laboratory Medicine and Pathobiology, University of Toronto, ON, Canada, 5Schulich Heart Research Program, Sunnybrook Health Sciences Centre, ON, Canada, 6Department of Medical Biophysics, University of Toronto, ON, Canada

Recent studies have demonstrated that an elevated T2 signal can delineate the area at risk (AAR) post acute myocardial infarction. However, it has been questioned whether the T2 elevation simply identifies the infarcted myocardium rather than the true AAR and whether edema is indeed present in the salvageable region. The purpose of the study was to assess whether T2-based AAR is influenced by the severity of myocardial injury, particularly by microvascular obstruction. Our study demonstrates that assessment of AAR by T2 is affected by the degree of myocardial damage, suggesting that edema extent may be modulated by infarct size.

3959.   52 Comparison of ADC and FA in EPI- and SSFP-based stimulated echo diffusion of the human myocardium
Elizabeth M Tunnicliffe1, Stefan Neubauer1, and Matthew D Robson1
1Oxford Centre for Magnetic Resonance Research, Radcliffe Department of Medicine, University of Oxford, Oxford, Oxon, United Kingdom

Cardiac diffusion imaging is of increasing interest in studying myocardial disease, both acute and chronic. This study compares diffusion metrics (ADC and FA) from and reproducibility of stimulated echo cardiac diffusion with two different readouts, EPI and SSFP, in normal volunteers. We obtain similar ADC (EPI: 1.09±0.09mm2/s; SSFP: 1.14±0.11mm2/s) and FA (EPI: 0.47±0.06; SSFP: 0.041±0.04) with the two sequences. . The EPI method has better reproducibility due to its higher SNR.

3960.   53 In vivo cardiac diffusion tensor imaging: Selecting a b-value and acquiring the reference data
Andrew David Scott1, Pedro Ferreira1,2, Sonia Nielles-Vallespin1,3, Laura-Ann McGill1,2, Philip Kilner1,2, Dudley Pennell1,2, and David Firmin1,2
1NIHR Funded Biomedical Research Unit, The Royal Brompton Hospital, London, London, United Kingdom, 2National Heart and Lung Institute, Imperial College London, London, United Kingdom, 3National Heart, Lung and Blood Institute, National Institute of Health, Bethesda, Maryland, United Kingdom

We investigate how the diffusion weighting (b-value) of the main and reference data affects cardiac diffusion tensor imaging. Helical angle, mean diffusivity and fractional anisotropy maps were obtained from data acquired with 21 combinations of b-values and three ways of calculating the reference images in 10 subjects. Using a monopolar stimulated echo sequence with a single shot EPI readout, we show that these parameter maps are improved by using more diffusion weighting than is typically used in-vivo and that the microvascular perfusion component of the measured diffusion can be attenuated by applying diffusion weighting to the reference images.

3961.   54 Cardiac ECV is More Robust than Post-Contrast Cardiac T1 for Evaluating Temporal Changes in Left Ventricular Fibrosis
Kyungpyo Hong1,2, Matthias Koopmann3, Eugene G. Kholmovski1, Eric C. Huang4, Nan Hu5, Richard Levenson4, Sathya Vijayakumar1, Derek J. Dosdall6, Ravi Ranjan6, and Daniel Kim1
1UCAIR, Department of Radiology, University of Utah, Salt Lake City, Utah, United States, 2Department of Bioengineering, University of Utah, Salt Lake City, Utah, United States, 3Department of Cardiovascular Medicine, University Hospital of Münster, Münster, Germany, 4Department of Pathology and Laboratory Medicine, University of California, Davis Medical Center, Sacramento, California, United States, 5Department of Internal Medicine, University of Utah, Salt Lake City, Utah, United States, 6CARMA, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, United States

While post-contrast cardiac T1 has been shown to be inversely correlated with interstitial fibrosis, it may be influenced by various confounders. Despite the theoretical advantages of extracellular volume (ECV) measurement for compensating confounders, systematic studies comparing post-contrast T1 and ECV are lacking. We sought to compare the effectiveness of post-contrast cardiac T1 and ECV for evaluating the temporal changes of left ventricular (LV) fibrosis in canine models with chronic atrial fibrillation. Compared with histologic quantification of interstitial fibrosis, ECV agreed better than post-contrast LV T1, suggesting that ECV is a more robust measure of extracellular space than post-contrast LV T1.

3962.   55 Comparisons of Canine ECV Measurements by CMR at 3T: IR- vs. SR-based Cardiac T1 Mapping and Bolus Injection vs. Slow Infusion of Contrast Agent
Kyungpyo Hong1,2, Eugene G. Kholmovski1, Derek J. Dosdall3, Christopher J. McGann3, Ravi Ranjan3, and Daniel Kim1
1UCAIR, Department of Radiology, University of Utah, Salt Lake City, Utah, United States, 2Department of Bioengineering, University of Utah, Salt Lake City, Utah, United States, 3CARMA, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, United States

While extracellular volume fraction (ECV) derived from hematocrit and pre- and post-contrast T1 measurements is an emerging method for assessment of diffuse cardiac fibrosis, systematic studies investigating the technical nuance are largely lacking. In well controlled canine experiment, we sought to compare ECV measurements between IR-based and SR-based cardiac T1 mapping pulse sequences, and ECV measurements between bolus injection and slow infusion protocols. Our results suggest that IR- and SR-based cardiac T1 mapping pulse sequences yield significantly different T1 and ECV measurements, and that 15 min after a bolus injection may not be dynamic equilibrium of contrast agent in canines.

3963.   56 Free-breathing myocardial T2* mapping using single-shot GRE-EPI and automatic non-rigid motion correction
Ning Jin1, Marie-Pierre Jolly2, and Orlando P. Simonetti3
1Siemens Healthcare, Columbus, OH, United States, 2Siemens Corporate Research, Princeton, NJ, United States, 3The Ohio State University, Columbus, OH, United States

We develop a new free-breathing technique for myocardial T2* mapping using single-shot gradient-echo echo-planar imaging (GRE-EPI) coupled with automatic non-rigid motion correction. We test our method in T2* phantoms and six healthy volunteers. In both phantom and volunteer studies, no significant difference was observed between the T2* measured using our proposed method and the T2* measured using the standard ECG-triggered segmented black-blood multi-echo gradient echo (mGRE) sequence. Our approach provides accurate myocardial T2* measurements during free-breathing and is insensitive to respiratory motion.

3964.   57 The validity of a Free Breathing Motion Corrected Phase Sensitive Inversion Recovery Sequence in the detection of Delayed Myocardial Enhancement at 3T.
Oisin Flanagan1, Bruce Spottiswoode2, Jeremy Collins3, Sven Zuehlsdorff2, Shivraman Giri4, Jad Bou Ayache3, Marcos Botelho3, Xiaoming Bi4, Michael Markl3, Robert Edelman5, and James Carr1
1Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States, 2Siemens Healthcare, USA, IL, United States, 3Northwestern University Feinberg School of Medicine, IL, United States, 4Siemens Healthcare, IL, United States, 5Northshore Healthsystem, IL, United States

The use of a free breathing motion corrected phase sensitive inversion recovery (FB MOCO PSIR) sequence to evaluate delayed enhancement (DE) in ischemic heart disease has been validated at 1.5T. In this study 22 patients underwent FB MOCO PSIR at 3T and it was found to be equal or superior to non motion corrected methods in detection of both ischemic and non-ischemic DE patterns. Initial experience suggests that it is safe alternative to standard methods at 3T and may be benficial in patients who are unable to breathold effectively.

3965.   58 Beyond Edema: Myocardial T2 in Chronic Myocardial Infarction Swine
Haiyan Ding1,2, Karl H. Schuleri3, Henry Halperin2,3, Roy Beinart3,4, M. Muz Zviman3, and Daniel A. Herzka2
1Department of Biomedical Engineering, Tsinghua University, Beijing, China, 2Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD, United States, 3Department of Medicine, Division of Cardiology, Johns Hopkins School of Medicine, Baltimore, MD, United States, 4Heart Institute, Sheba Medical Center, Tel Aviv University, Ramat Gan, Israel

T2 relaxation time correlates with pathologic processes within myocardial tissue. Recently, quantitative T2 mapping has been shown more robust than qualitative clinical T2-weighted imaging in many diseases though most effort has been directed at acute injury and visualization of edema. Chronic myocardial infarction (MI) affects both water and collagen content that in turn impacts relaxation times. We hypothesize that quantitative T2 measurements may characterize infarct in chronic MI without extraneous contrast agent. A swine model was studied with both in vivo MRI and ex vivo histology. We demonstrate that myocardial T2 mapping has the potential to noninvasively characterize chronic MI without exogenous contrast agents.

3966.   59 Fat-water separated myocardial T1 imaging of the right ventricle with IDEAL-T1 saturation recovery gradient echo imaging
Joseph J Pagano1, Kelvin Chow1, Ray Yang1, and Richard B Thompsoon1
1Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada

Myocardial T1 imaging is an emerging tool for tissue characterization, however its use has been limited to the left ventricle. We developed a novel MRI sequence (IDEAL-T1) that combines fat-water separation and T1 imaging, with and without black blood preparation, for myocardial T1 imaging, including the right ventricle. We evaluated IDEAL-T1 using Bloch equation simulations, phantom, and in vivo studies. IDEAL-T1, with and without dark blood preparation, showed good agreement in phantoms and in vivo. The dark blood preparation allowed for right ventricular analysis in all, however showed lower T1 values than bright blood images likely due to perfusion effects.

3967.   60 Cone of Uncertainty Assessment in Cardiac Diffusion Tensor Imaging: A Comparison between Spin Echo and Stimulated Echo Sequences
Anh T Van1, Anja C.S. Brau2, Rolf F. Schulte3, Martin A. Janich3, and Axel Haase1
1Zentralinstitut für Medizintechnik, Technische Universität München, Garching, Bavaria, Germany, 2MR Applications & Workflow, GE Healthcare, Garching, Bavaria, Germany, 3GE Global Research, Garching, Bavaria, Germany

In cardiac diffusion imaging, spin echo (SE) and stimulated echo (STE) diffusion sequences measure diffusion at very different diffusion time. It has been reported that the resulted diffusion parameters are different. In this work, we investigate how the difference in derived diffusion parameters from SE and STE experiments, if exists, affects the estimation of myocardial fiber organization through the assessment of the cone of uncertainty (COU) of the major eigenvector of the diffusion tensor.

3968.   61 In vivo cardiac diffusion tensor imaging using a spiral trajectory
Andrew David Scott1, Pedro Ferreira1, Sonia Nielles-Vallespin1,2, Iain Pierce1,3, Laura-Ann McGill1,3, Dudley Pennell1,3, and David Firmin1,3
1NIHR Funded Biomedical Research Unit, The Royal Brompton Hospital, London, London, United Kingdom, 2National Heart, Lung and Blood Institute, National Heart and Lung Institute, Bethesda, Maryland, United States, 3National Heart and Lung Institute, Imperial College London, London, United Kingdom

In vivo cardiac diffusion tensor imaging (cDTI) is commonly performed using a stimulated echo sequence (STEAM) with an echo planar imaging (EPI) readout. Here we combine a zonal excitation to excite a small square field of view with a single-shot spiral readout and STEAM. The centre-out nature of spiral trajectories results in reduced TE and, therefore less T2 decay than for the equivalent EPI sequence. In this first demonstration of spiral cDTI, helical angle, mean diffusivity and fractional anisotropy values match those in previous literature. With techniques like parallel imaging, spatial resolution may be improved beyond that available using EPI.

3969.   62 Optimized Sampling Time Selection for the Saturation Curve for Myocardial T1 Mapping
Mehmet Akçakaya1, Sebastian Weingärtner1, Sebastien Roujol1, and Reza Nezafat1
1Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States

In myocardial T1 mapping, there is a degree of freedom in selecting which points on the relaxation curve are sampled. However, optimal selection of the timing of the sampling points has not been studied. In this study, we sought to develop a framework for optimal selection of timing of sampling points to achieve improved precision of SR based T1 mapping.

3970.   63 Right ventricular myocardial T1 and extracellular volume fraction (ECV) measurements using high resolution ANGIE T1 mapping
Bhairav Bipin Mehta1, Kenneth C Bilchick2, Xiao Chen1, Michael Salerno1,2, and Frederick H Epstein1,3
1Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, United States, 2Department of Medicine, Cardiology Division, University of Virginia, Charlottesville, Virginia, United States, 3Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, United States

T1 mapping is routinely used for quantitative assessment of left ventricular fibrosis. Assessment of fibrosis in thin structures such as the right ventricular (RV) and left atrial walls would be valuable in various disorders. However, MOLLI, the current technique, has limited spatial resolution for these applications. We previously developed a sequence termed ANGIE, which enables high-resolution T1 mapping. In the present study, we investigated T1 mapping of the RV in healthy volunteers and heart failure patients using ANGIE. Using ANGIE, we measured the first RV T1 estimates (980±96ms) in healthy volunteers and RV ECV estimates (28.0±1.6%) in heart failure patients.

3971.   64 Diffusion Tensor MRI of the Entire Human Heart in Vivo with Blipped-CAIPI and Simultaneous Multislice Acquisition
Choukri Mekkaoui1, Timothy G Reese2, Himanshu Bhat3, Stephen T Cauley2, Marcel P Jackowski4, Kawin Setsompop2, and David E Sosnovik5
1Harvard Medical School - Massachusetts General Hospital, Boston, MA, United States, 2Athinoula A Martinos center for Biomedical imaging, Boston, United States, 3Siemens, boston, United States, 4University of São Paulo, São Paulo, Brazil, 5Harvard Medical School - Massachusetts General Hospital, Boston, United States

The utilization of cardiac DTI has been limited in part by its temporal inefficiency. Here we show that simultaneous multislice acquisition using the blipped-CAIPI technique can be used to increase coverage and reduce scan time by a factor of 3. In vivo DTI of the entire human heart can be performed with this technique in 40 minutes with acceptable resolution, without interslice gaps, and with excellent image quality. The improved coverage and reduced scan time produced by blipped-CAIPI have the potential to improve the accuracy of cardiac DTI and facilitate its clinical use.

3972.   65 Optimization of Post Contrast T1 Mapping Time for Diagnostic Assessment of Myocardial Amyloid
Mitchell Anthony Cooper1, Thanh D. Nguyen2, Jonathan Weinsaft3, Matthew Maurer4, Suzanne Lentzsch4, Heather Landau5, Jiwon Kim5, Sattar Gojraty3, Silvina Dutruel2, Martin Prince2, and Yi Wang2
1Biomedical Engineering, Cornell University, Ithaca, New York, United States, 2Radiology, Weill Cornell Medical College, New York, NY, United States,3Cardiology, Weill Cornell Medical College, New York, New York, United States, 4Columbia University, New York, New York, United States, 5Memorial Sloan Kettering Cancer Center, New York, New York, United States

Cardiac amyloidosis is a serious condition in which insoluble proteins accumulate in the extracellular space of the myocardium, resulting in impaired cardiac function. The current gold standard for the evaluation of cardiac involvement is endomyocardial biopsy, an invasive procedure not well suited for screening purposes or serial assessment. Myocardial T1 mapping after the administration of a Gadolinium (Gd) contrast agent, which acts as a diffusible tracer, has emerged as a viable noninvasive tool to detect amyloid infiltration and to quantify changes in the extravascular extracellular volume (ECV) in cardiac amyloidosis (1-3).The purpose of this study was to identify the optimal T1 mapping time by performing numerical simulation of a tracer kinetic model as well as by measuring myocardial T1 at various time points in healthy and amyloid positive patients.

3973.   66 Microstructural Characterization of the Infarct Border Zone in Humans with In Vivo Diffusion Tensor MRI and “Gray-Zone” Late Gadolinium Enhancement
Choukri Mekkaoui1, Christian T Stoeck2, Marcel P Jackowski3, Timothy G Reese4, Sebastian Kozerke5, and David E Sosnovik6
1Harvard Medical School - Massachusetts General Hospital, Boston, MA, United States, 2University and ETH Zurich, zurich, Switzerland, 3University of São Paulo, São Paulo, Brazil, 4Athinoula A Martinos center for Biomedical imaging, Boston, United States, 5University and ETH Zurich, Zurich, Switzerland,6Harvard Medical School - Massachusetts General Hospital, Boston, United States

The infarct border zone plays a major role in the development of mechanical and electrical dysfunction during post-infarction remodeling. We used in vivo diffusion tensor MRI (DTI) and late gadolinium enhancement (LGE) in patients with recent myocardial infarctions to examine the properties of the infarct border zone. We show that an increase in LGE in the border zone of just 1 standard deviation above normal is associated with significant microstructural abnormality, including marked heterogeneity of myofiber tract orientation and loss of tract coherence.

3974.   67 Noninvasive assessment of cardiomyocyte breadth from extracellular volume fraction with MRI
Shi-Jun Zhang1, Jiyang Jin1, Min Chen1, Lin Wang1, Andreas Greiser2, and Shenghong Ju1
1Department of Radiology, Zhongda Hospital, Southeast University, Nanjing, Jiangsu Province, China, 2Siemens AG Healthcare Sector, Bayern, Germany

The myocardial extracellular volume fraction (ECV) is a reflection of the relative volume of the extracellular space and cells in myocardium, and we infer that the size of the cardiomyocytes affects ECV and in the other hand could be reflected by ECV. We found through the present study of swine that ECV correlates negatively with cardiomyocyte breadth under physiological conditions, indicating ECV might be a potential MRI biomarker for cardiomyocyte size estimation in vivo.

3975.   68 Transcytolemmal Water-Exchange Slows in Infarcted Myocardium
James Goldfarb1,2 and Wenguo Zhao1
1St Francis Hospital, Roslyn, NY, United States, 2Program in Biomedical Engineering, SUNY Stony Brook, Stony Brook, NY, United States

We measured and compared the transcytolemmal cellular water exchange rates of fibrotic and viable myocardium in patients with chronic myocardial infarcts. Transcytolemmal water exchange rates differed between infarcted and viable myocardium. Viable myocardium can be assumed to be in fast exchange limit. Infarcted myocardium has significantly slower exchange which alters the linearity of contrast curve shapes.

3976.   69 Magnetic Resonance Imaging (MRI) Relaxometry: Assessment of reproducibility between Magnetic Resonance scanners at 1.5T
Qurain T Alshammari1,2, Graham J Galloway1, Mark W Strudwick3,4, Wendy E Strugnell5, and Christian Hamilton-Craig1,6
1Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, Australia, 2College of applied Medical Science, Hail, Saudi Arabia, 3Dept of Medical Imaging and Radiation Science, Monash University, Melbourne, Australia, 4School of Information Technology and Electrical engineering, The University of Queensland, Queensland, Australia, 5The Richard Slaughter Centre of Excellence in Cardiac MRI, Prince Charles Hospital, Queensland, Australia,6University of Washington, Seattle, United States

Native T1 and T2* relaxometry are important techniques for quantitative analysis of myocardial substrate. 10 healthy volunteers underwent CMR on two 1.5T systems (Siemens Avanto and Siemens Aera) at a 3 year interval using a Modified Look-Locker Inversion ‘MOLLI’ 3,3,5 and T2* sequences. T1-MOLLI and T2* demonstrate high consistency and inter-study reproducibility between scanners, with no significant difference in T1 and T2* after 3 years. CMR relaxometry should therefore be comparable between centres for follow-up in individual patients using different CMR scanners, with different bore sizes, within the same vendor at 1.5T

3977.   70 Cardiovascular Magnetic Resonance Radial and Circumferential Strain: comparison between SSFP feature tracking, MRI tagging, and speckle tracking Echocardiography
Qurain T Alshammari1,2, Wendy E Strugnell3, Jonathan Chan4, Darryl J Burstow5, and Christian Hamilton-Craig1,6
1Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, Australia, 2College of Applied Medical Science, Hail, Saudi Arabia, 3The Richard Slaughter Centre of Excellence in Cardiac MRI, The Prince Charles Hospital, Queensland, Australia, 4Heart Foundation Research Centre, Griffith University, Gold Coast, Australia, 5Department of Echocardiography, The Prince Charles Hospital, Qeensland, Australia, 6University of Washington, Seattle, United States

Myocardial deformation imaging with strain imaging using speckle tracking Echocardiography (STE) and Cardiovascular Magnetic Resonance tagging now has been applied for assessment of myocardial deformation. Recently, feature tracking on standard steady state free precession imaging (SSFP–FT) has been developed for the assessment myocardial deformation. The purpose of this study was to compare circumferential and radial strain by feature tracking on SSFP cine CMR images as compared to SPAMM tagging technique and speckle tracking echocardiography. The result support that the radial and circumferential strain with SSFP-FT has a good agreement with tagging and Echocardiography methodologies.

3978.   71 Myocardial fibrosis by CMR LGE in a large cohort of pediatric thalassemia major patients
Antonella Meloni1, Maddalena Casale2, Aldo Filosa2, Rosellina Rosso3, Antonino Vallone4, Gianluca Valeri5, Daniele De Marchi1, Vincenzo Positano1, Massimo Lombardi1, and Alessia Pepe1
1CMR Unit, Fondazione G.Monasterio CNR-Regione Toscana and Institute of Clinical Physiology, Pisa, Italy, 2UOSD Centro per le Microcitemie, AORN Cardarelli, Napoli, Italy, 3U.O. Talassemie ed Emoglobinopatie, Ospedale Ferrarotto CT Az. Osp. Universitaria Policlinico Vittorio Emanuele, Catania, Italy,4Istituto di Radiologia, Az. Osp. "Garibaldi" Presidio Ospedaliero Nesima, Catania, Italy, 5Dipartimento di Radiologia, Azienda Ospedaliero-Universitaria Ospedali Riuniti "Umberto I-Lancisi-Salesi", Ancona, Italy

In pediatric patients with thalassemia major myocardial fibrosis is not a rare finding to keep in mind in the cardiological management. When appropriate treatment has been administered since early childhood, CMR LGE can be postponed until 13 years of age. By the natural history of this large cohort of pediatric patients where HCV infection has been appropriately prevented, myocardial fibrosis seems to be associated with cardiac iron and high cardiac output.

3979.   72 Imaging and visualization of cardiac muscle microstructure in rats using high-resolution MRI
Silun Wang1, Xulei Qin2, Xiaodong Zhang1, Mary B. Wagner3, and Baowei Fei2,4
1Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States, 2Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, United States, 3Department of Pediatrics, Emory University, Atlanta, GA, United States, 4Biomedical Engineering, Emory University, GA, United States

We analyze the cardiac muscle microstructural characteristics in rats using SWI and DTI imaging. SWI provided useful information to explore the anatomical characteristics of cardiac muscle, including left ventricle and papillary muscle and the cardiac vascular system in rats. DTI cardiac muscle tractography identified the orientation and distributions of cardiac muscle fibers. The current results are potentially useful to monitor cardiac muscle pathology including ischemia induced cardiac muscle damage and abnormal iron deposit as well as evaluations of treatment effects.