ISMRM 23rd Annual Meeting & Exhibition • 30 May - 05 June 2015 • Toronto, Ontario, Canada

Electronic Poster Session • Cardiovascular
4447 -4470 Myocardial Tissue Differentiation
4471 -4494 Cardiac Perfusion & Function
4495 -4518 CE & Non-CE NRA
4519 -4542 Vessel Wall & Cardiovascular Image Processing
4543 -4566 Let It Flow
4567 -4590 New Insights & Innovations in Cardiovascular MRI

Note: The videos below are only the slides from each presentation. They do not have audio.


Thursday 4 June 2015
Exhibition Hall 10:30 - 11:30

  Computer #  
4447.   1 High-resolution three-dimensional ANGIE T1 mapping of the heart
Bhairav Bipin Mehta1, 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

Assessment of fibrosis in thin structures such as the right ventricular (RV) and left atrial walls would be valuable in various disorders. However, current cardiac T1 mapping techniques have limited spatial resolution for these applications. We previously developed a 2D sequence, ANGIE, which enables high-resolution T1 mapping. However, high resolution 2D imaging is limited by low SNR and time efficiency. In the present study, we extend ANGIE to perform high-resolution three-dimensional (3D) T1 mapping of the heart within a clinically acceptable scan time. 3D ANGIE was evaluated by performing comparisons with 2D ANGIE and 2D MOLLI in six healthy volunteers.

4448.   2 Evaluation of Extracellular Volume with limited T1 mapping planes using MOLLI technique
Wei Li1, Eugene Dunkle2, Claire Feczko3, Shivraman Giri4, and Edelman R Robert1
1Northshore University HealthSystem, Evanston, IL, United States, 2Northshore University HealthSystem, IL, United States, 3Northshore University HealthSystem, Evanston, IL, United States, IL, United States, 4Siemens Healthcare, Chicargo, IL, United States

To assess the effects of T1 mapping and ECV calculating by adding MOLLI T1 mapping sequence to our routine cardiac MR work up protocol, eighty-eight patients, who had pre- and post- Gd contrast MOLLI acquisitions for T1 mapping and ECV calculation in addition to routine sequences for cardiac work up, were reviewed. Only mid-short axis and mid-4chember views were acquired for T1 mapping to avoid increasing the exam time too much. We observed that adding MOLLI T1 mapping sequence to a cardiac work up protocol is a simple and effective way to catch T1 and myocardial ECV message even only limited planes were applied.

4449.   3 Improving the precision of arrhythmia-insensitive rapid (AIR) T1 mapping through optimization of saturation recovery time delay
Kyle Erjin Jeong1,2, Kyungpyo Hong1,2, and Daniel Kim2,3
1Bioengineering Department, University of Utah, Salt Lake City, Utah, United States, 2Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, Utah, United States, 3Department of Radiology, University of Utah, Utah, United States

Arrhythmia insensitive rapid (AIR) cardiac T1 mapping is particularly useful for imaging patients with arrhythmia and/or rapid heart rates. The original AIR pulse sequence was designed with saturation recovery time delay (TD) of 600 ms. We sought to perform numerical simulation to derive an optimal TD to achieve a good balance between precision and scan time. Our numerical experiments show that optimal TD is 780 ms for expected T1 range of 400-2,000 ms at 3T. This simulation framework is adaptable for patients with different heart rates.

4450.   4 Prognostic Value of Hypointense Cores within Chronic Myocardial Infarctions on Balanced Steady-State Free Precession MRI for the Prediction of Malignant Ventricular Arrhythmias
Ivan Cokic1, Avinash Kali1, Hsin-Jung Yang1, Raymond Yee2, Richard Tang1, Mourad Tighiouart3, Xunzhang Wang4, Warren M. Jackman5, Sumeet S. Chugh4, James A. White6, and Rohan Dharmakumar1
1Biomedical Sciences - BIRI, Cedars-Sinai Medical Center, Los Angeles, California, United States, 2Department of Medicine - Division of Cardiology, London Health Sciences Centre, London, ON, Canada, 3Biostatistics and Bioinformatics Research Center, Cedars-Sinai Medical Center, Los Angeles, California, United States, 4Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States, 5Heart Rhythm Institute, University of Oklahoma, Oklahoma City, OK, United States, 6Department of Cardiac Sciences, University of Calgary - Stephenson Cardiac Imaging Centre, Calgary, AB, Canada

This study will help to improve the risk stratification for ICD implantation.

4451.   5 Free-breathing myocardial 3D T1 mapping using inversion time specific image-based respiratory navigators
Markus Henningsson1, Rene Botnar1, and Tobias Voigt1,2
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 2Clinical Research Europe, Philips Research, Hamburg, United Kingdom

Free-breathing whole-heart myocardial T1 mapping is technically challenging due to the difficulty of respiratory motion compensation. Conventional respiratory gating techniques are impractical due to the prolonged scan time associated with these approaches. In this work we propose an image-based navigator approach which allows for direct tracking of the respiratory motion of the heart. Although this means navigators at different inversion times have different contrast, potentially leading to registration errors, we solve this problem by using a separate navigator reference for each inversion time. We evaluate this free-breathing three-dimensional T1-mapping method in 7 healthy volunteers and compared it to 2D T1-mapping.

4452.   6 Assessment of Acute Cryo and RF Ablation Lesions by Non-contrast and Contrast Enhanced MRI Techniques: Similarities and Differences
Eugene G. Kholmovski1, Ravi Ranjan2, Joshua Silvernagel2, and Nassir F. Marrouche2
1UCAIR, Department of Radiology, University of Utah, Salt Lake City, Utah, United States, 2CARMA Center, University of Utah, Salt Lake City, Utah, United States

Catheter radio-frequency (RF) and cryo-ablations are being increasingly used for treatment of atrial fibrillation and ventricular tachycardia. However, reported success rate of the procedures is moderate. The main causes of procedure failure are tissue recovery and gaps in ablation. The extent of ablations and lesion permanency cannot be accurately evaluated by conventional electro-physiological measurements. MRI can be used to assess lesions dimension and to predict their permanency. In this study, we have compared visibility of acute cryo and RF ablation lesions using non-contrast and contrast enhanced MRI techniques. Cryo and RF lesions have similar appearance in post-contrast T1w and LGE MRI images. However, the lesions have significantly different appearance in native T1w and T2w images.

4453.   7 Non-contrast MRI for Assessing Myocardial Fibrosis: Initial Study in a Canine model of Myocardial Reperfusion after Drug Treatments
Jie Zheng1, Qian Yin1, David Muccigrosso1, Ridong Chen2, and Dana Abendschein3
1Radiology, Washington University School of Medicine, Saint Louis, Missouri, United States, 2APT Therapeutics, Saint Louis, Missouri, United States,3Cardiology Division, Washington University School of Medicine, Saint Louis, Missouri, United States

A non-contrast MRI fibrosis index method was developed to consecutively assess myocardial fibrosis in a canine model after induced myocardial infarction, reperfusion, and an experimental drug APT102 treatment. In comparison with controlled study, the fibrosis index demonstrated similar trend from baseline to 24 hours after APT102 treatments, but dramatically decreased at 7 days. This was confirmed by histopathological stains in myocardial tissues.

4454.   8 T1ρ-mapping of the heart in a single breath-hold - permission withheld
Joep van Oorschot1, Hamza El Aidi1, Fredy Visser2, Peter Luijten1, Tim Leiner1, and Jaco Zwanenburg1
1University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, 2Philips Healthcare, Best, Noord-Brabant, Netherlands

T1ρ-mapping shows promising results for the endogenous detection of myocardial fibrosis. A T1ρ-map can be obtained by multiple T1ρ-weighted images with different spin-lock (SL) preparation times. We propose a cardiac T1ρ-mapping method in a single breath-hold. Five healthy volunteers and 2 patients with chronic myocardial infarction were scanned. T1ρ-mapping was performed by acquiring 5 images with different SL preparation times (SL = 0, 10, 20, 30, 40 ms). High resolution T1ρ-maps were successfully acquired in all subjects. The mean T1ρ-relaxation time was 52.7±3 ms. Coefficient of repeatability in the healthy subjects was 3.74 ms, and in infarct patients 4.59 ms.

4455.   
9 Geometrical complexity of left ventricular endocardial border measured by fractal analysis: a comprehensive study
Andrea S. Dell'Aquila1, Sofia A. Papadopoulou1, Sanjay Sharma1, Lisa J. Anderson1, and Taigang He1
1Cardiovascular Sciences Research Centre, St George's, University of London, London, Greater London, United Kingdom

Increased left ventricle trabeculations (LVT) are frequently seen in various cardiac diseases. LVT can be accurately delineated from cardiovascular magnetic resonance (CMR) images, but methods to quantify them remain limited. Fractal analysis of CMR images was recently proposed and proved to be an effective quantitative measure in distinguishing normal from hypertrophic cardiomyopathy. In this study, we quantified LVT using fractal dimension in a large cohort of normal controls, athletes with and without athlete heart syndrome, patients with non-compaction, hypertrophic and non-ischaemic dilated cardiomyopathy. Of clinical importance, this study demonstrates a wide spectrum of LVT patterns between normal cardiac conditions and abnormal ones, such as hypertensive heart disease, hypertrophic cardiomyopathy and left ventricular non-compaction.

4456.   10 Oxygen-enhanced T2* cardiac magnetic resonance imaging in non-ischemic cardiac diseases
Satoshi Kawanami1, Michinobu Nagao1, Masato Yonezawa2, Yuzo Yamasaki2, Takeshi Kamitani2, Torahiko Yamanouchi2, Tomomi Ide3, Ryohei Funatsu4, Hidetake Yabuuchi5, and Hiroshi Honda2
1Molecular Imaging & Diagnosis, Kyushu University, Graduate School of Medicine, Fukuoka, Fukuoka, Japan, 2Clinical Radiology, Kyushu University, Graduate School of Medicine, Fukuoka, Fukuoka, Japan, 3Cardiovascular Medicine, Kyushu University, Graduate School of Medicine, Fukuoka, Fukuoka, Japan, 4Radiological Technology, Kyushu University Hospital, Fukuoka, Fukuoka, Japan, 5Health Sciences, Kyushu University, Graduate School of Medicine, Fukuoka, Fukuoka, Japan

In this study, we analyzed T2* value in the mid-left ventricular septum avid both normoxia and hyperoxia among clinical cases with non-ischemic heart disease. The oxygen-enhanced T2* cardiac magnetic resonance (CMR) was promising to evaluate the myocardial blood-oxygen dependent (BOLD) response to hyperoxia. The development of quantitative evaluation technique for the oxygen metabolism in human myocardium in vivo has opened up new avenues for the study of the cardiac pathophysiology. To our knowledge, this is the first clinical study that has assessed the myocardial ĢT2* response to hyperoxic respiratory challenge by BOLD-CMR.

4457.   11 Feasibility Analysis of the Chemical Exchange and T1 Measurement Using Progressive Saturation (CUPS) Method for In Vivo Application to Human Myocardium
David A. Reiter1, Mustapha Bouhrara1, and Richard G Spencer1
1Laboratory of Clinical Investigation, NIH/National Institute on Aging, Baltimore, MD, United States

The creatine kinase (CK) reaction is considered to be important for maintaining ATP supply to demand in the myocardium over the wide operating range of cardiac output. The CUPS method has been previously applied to measurements of chemical exchange rates, such as CK flux, under preclinical experimental conditions. The current work uses Cramér-Rao lower bound analysis and Monte Carlo simulations, targeting in vivo human MRS conditions for studies of the myocardium at clinical field strength, demonstrating the feasibility of this approach for reliable measurement of CK fluxes under a wide range of experimental and physiological conditions.

4458.   
12 Small animal myocardial T1 mapping with respiratory motion navigated Look-Locker imaging
Pan-Ki Kim1, Joonsung Lee1, and Byoung Wook Choi1
1Yonsei University, Seoul, Korea

The quantification of T1 relaxation time has become an important indicator for diffuse cardiomyopathies. In small animal studies, such as mouse and rat, fast heart beats and respiratory rates are major obstacles to use clinical T1 mapping methods. For small animal T1 mapping, SALLI and mCINE-IR had been reported using the Look-Locker scheme. Since the Look-Locker recovery evolution has to be consistently maintained, the respiratory gating is particularly challenging. In general, the multiple averages were applied to avoid motion artifacts. In this study, respiratory motion navigated Look-Locker imaging (NALLI) was proposed to overcome respiratory motion artifacts for small animal myocardial T1 mapping. To evaluate feasibility, the proposed method was performed for phantoms and a normal mouse.

4459.   13 3D Late Gadolinium Enhancement Imaging using CENTRA-PLUS ordering with Weighted Navigator Acquisition: Feasibility of Surgically Implanted RV Patch Volume Quantification in Swine Model
Keigo Kawaji1, Akiko Tanaka2, Mita Patel1, Sui-Cheng Wang3, Hui Wang4, Takeyoshi Ota2, Roberto M. Lang1, and Amit R. Patel1
1Medicine, Section of Cardiology, The University of Chicago, Chicago, Illinois, United States, 2Surgery, The University of Chicago, Chicago, Illinois, United States, 3Biomedical Engineering, Northwestern University, Evanston, Illinois, United States, 4Philips Medical Systems, Cleveland, Ohio, United States

In this study, we propose a novel ECG-triggered and navigator-gated 3D LGE acquisition method that uses CENTRA-PLUS profile/view ordering that is designed to acquires central and peripheral k-space with a weighted navigator gating window. Six pigs were surgically implanted with Right Ventricular (RV) patches, and MRI was performed 7-9 weeks after surgery. RV patch volume quantification was performed using both 2D PSIR LGE and the proposed 3D PSIR LGE images, and volume measurement errors were compared to the gold standard direct measurements made on the surgically excised RV patch region.

4460.   14 Whole heart DTI using asymmetric bipolar diffusion gradients
Martijn Froeling1,2, Gustav J Strijkers3, Aart J Nederveen2, and Peter R Luijten1
1Radiology, UMC Utrecht, Utrecht, Netherlands, 2Radiology, AMC, Amsterdam, Netherlands, 3Biomedical engineering and physics, AMC, Amsterdam, Netherlands

The aim of this study was to develop SE-based cardiac diffusion MRI protocol with second order moment nulling, thus also compensating for acceleration, and to compare its performance to that of Stejskal-Tanner and bipolar gradients waveforms. Using this approach we have shown that it is feasible to quantify the transmural helix angle for the entire heart in five subjects.

4461.   15 The Accuracy of Quantitative MR Elastography in an Anatomically Accurate Diastolic Cardiac Phantom
Arvin Arani1, Shivaram Poigai Arunachalam1, Phillip Rossman1, Armando Manduca2, David S. Lake1, Joshua D. Trzasko1, Kiaran P. McGee1, Kevin J Glaser1, Richard L. Ehman1, and Philip Araoz1
1Radiology, Mayo Clinic, Rochester, Minnesota, United States, 2Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States

Normal cardiac function is dependent on the mechanical properties of the myocardium, which may serve as a valuable predictor of disease. Several groups have investigated the use of MR Elastography to measure stiffness in vivo. However, a thorough evaluation of the accuracy of the reported stiffness measurements and the optimal experimental settings has not been well established. The purpose of this work, was to evaluate the accuracy of 3D MRE direct inversion at multiple frequencies, on curl wave fields in a morphologically accurate left ventricular phantom using dynamic mechanical testing (DMA) as the reference standard.

4462.   16 Wideband Arrhythmia-Insensitive-Rapid (AIR) Cardiac T1 mapping Pulse Sequence for suppressing Image Artifacts induced by ICD
Kyungpyo Hong1,2, Eun-Kee Jeong1, 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

Standard cardiac T1 mapping generates image artifacts in patients with implantable cardioverter-defibrillator (ICD). We propose to perform successful cardiac T1 mapping in patients with ICD by incorporating a saturation radio-frequency pulse with wide frequency bandwidth (8.9 kHz). In 11 subjects with ICD, compared with T1 measurements produced by standard T1 mapping without ICD as the control, T1 measurements by standard T1 mapping with ICD were significantly different (p < 0.05), whereas T1 measurements by wideband T1 mapping with ICD were not significantly different. This study demonstrates the feasibility of wideband cardiac AIR T1 mapping for suppressing artifacts induced by ICD.

4463.   17 Late Gadolinium Enhancement for Left Ventricular Lead Guidance in Cardiac Resynchronization Therapy: Comparison of 3D Free-breathing IR-FLASH vs 2D Breath-hold Phase-Sensitive IR
Adrian Lam1, Ankit Parikh2, Michael Lloyd2, and John Oshinski1,3
1Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States, 2Department of Medicine, Emory University, Georgia, United States, 3Department of Radiology and Imaging Science, Emory University, Georgia, United States

Optimal patient response to Cardiac Resynchronization Therapy is associated with left ventricular lead implantation in the latest contracting segment of the myocardium that is not predominantly myocardial scar. However, transvenous implantation through the coronary sinus limits lead implantation locations to regions that can be accessed by the coronary veins. A 3D, contrast-enhanced, free-breathing inversion recovery (IR) FLASH sequence can visualize the coronary veins and can be used for late gadolinium enhanced (LGE) imaging. The purpose of this study was to evaluate the potential of 3D, LGE, free-breathing, IR-prepared FLASH compared to the clinical standard, 2D LGE Phase Sensitive Inversion-Recovery (PSIR).

4464.   18 Improved Arrhythmia-Insensitive-Rapid (AIR) cardiac T1 Mapping with Pulse Sequence Optimization: k-space Ordering and Flip Angle
Kyungpyo Hong1,2 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

Arrhythmia-insensitive-rapid (AIR) cardiac T1 mapping pulse sequence is a promising method for imaging patients with rapid heart rates and/or arrhythmia. We sought to improve further AIR cardiac T1 mapping through k-space ordering and flip angle optimization. In human volunteers and patients, centric k-space ordering acquisitions yielded image artifacts arising from eddy currents, whereas centric-pair k-space ordering acquisitions suppressed image artifacts. For flip angles ranging from 25-65°, standard deviation decreased with flip angles, with significant difference in mean T1 values for any of the 4 types of measurement (native myocardial T1, native blood T1, post-contrast myocardial T1, and post-contrast blood T1).

4465.   19 Measurement and quantification of sheep cardiac myocyte and sheetlet orientation from high-field 80 × 80 × 160 µm contrast-enhanced T1W MRI.
Stephen Henry Gilbert1, Julie Magat2, Mark Trew3, Valery Ozenne2, Fanny Vaillant2, Jérôme Naulin2, Olivier Bernus2, and Bruno Quesson2
1Mathematical Cell Physiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany, 2L'Institut de rythmologie et modélisation cardiaque LIRYC, Pessac, France, 3Auckland Bioengineering Institute, Auckland, New Zealand

We present first high-spatial resolution ex vivo MRI of myocardial sheetlet structure from a human sized heart (the sheep heart), obtained at 9.4T/30cm, using a novel 7 elements array coil. This image data allowed us to reconstruct the ventricular sheetlet and myocyte orientations using structure tensor image analysis. We demonstrate that this methodology that has only previously been applied to small mammalian hearts is scalable to large animal clinical models. This methodology allows correlation of explanted myocardial structure to in vivo and myocardial strain/shear distributions in large animal clinical models and is directly applicable to normal/pathologic human hearts after transplantation.

4466.   20 Hemorrhage alters T2 BOLD response in remote myocardium following acute myocardial infarction in a porcine model
Nilesh R Ghugre1,2, Xiuling Qi1, Jennifer Barry1, Bradley H Strauss3, and Graham A Wright1,2
1Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada, 2Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, 3Schulich Heart Program, Sunnybrook Health Sciences Centre, Toronto, ON, Canada

Myocardial hemorrhage is a frequent complication in acute myocardial infarction; however its impact on the remote tissue is currently unknown. The aim of our study was to investigate whether hemorrhage contributes to a remote myocardial response using a novel porcine model of myocardial hemorrhage. To this end, a blood-oxygen-level-dependent (BOLD) approach with T2 contrast was employed to evaluate vasodilator function using a stress agent. We noted an elevated remote T2 in the rest state that was associated with a suppressed stress response under hemorrhagic conditions. Our study demonstrates that hemorrhage not only promotes cellular and microvascular damage and inflammation but may also further be responsible for remote myocardial remodeling post-infarction.

4467.   21 Intralipid Reduces Post-MI Ventricular Remodeling and Heart Failure after Ischemic Injury
Yijen Lin Wu1,2, Fang-Cheng Yeh3, and Chien Ho4
1Developmental Biology, University of Pittsburgh, Pittsburgh, PA, United States, 2Rangos Research Center Imaging Core, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, United States, 3Psychology, Carnegie Mellon University, Pittsburgh, PA, United States, 4Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, United States

Coronary heart disease is the leading cause of death in US. Timely re-circulation has greatly decreased 30-day in-hospital death, and increased survival rate during the acute phase of myocardium infarction (MI). However, even with successful blood-flow restoration, ischemia reperfusion injury (IRI) can result in greater tissue damage and adverse remodeling. The rate of developing post-MI heart failure increases as the acute mortality decreases. Long-term post-MI ventricular remodeling and the consequent potential heart failure remains a challenge. We report here that Intralipid can preserve heart function after IRI can reduce long-term post-MI ventricular remodeling.

4468.   22 Early detection of doxorubicin induced diffuse myocardial fibrosis by contrast enhanced magnetic resonance imaging in rabbit modell: compared with histology and electron microscopy.
Byoung Wook Choi1, Yoo Jin Hong1, Chul Hwan Park1, and Panki Kim1
1Radiology, Yonsei University, Seoul, Korea

Cardiotoxicity of doxorubicin in patients with cancer causes irreversible myocardial damage leading to worse prognosis. To detect early stage of cardiotoxicity, T1 mapping and extracellular volume fraction was tested to determine the feasibility for detection of diffuse myocardial fibrosis in an early stage of cardiotoxicity. There was a good correlation between myocardial ECV measurement and the degree of fibrosis on histology.

4469.   23 Left atrial strain is correlated to atrial fibrosis by late gadolinium enhancement, in an AF population.
Dana C Peters1, Daniel Cornfeld1, Albert J Sinusas2, James S Duncan1, Xenios Papademetris1, Karl Grunseich1, and Sudhakar Chelikani1
1Radiology, Yale School of Medicine, New Haven, CT, United States, 2Cardiology, Yale School of Medicine, New Haven, CT, United States

We tested the hypothesis that left atrial strain was inversely correlated to atrial fibrosis. Left atrial strain was assessed using 2-chamber and 4-chamber cine images in sixteen patients with AF, and 13 control patients, using atrial contouring and a point-matching algorithm. Left atrial late gadolinium enhancement (LGE) was also assessed to obtain a fibrosis score. Average 4-chamber and 2-chamber strains were inversely correlated to the extent of atrial fibrosis in AF subjects, but not in controls. Regional strains also showed strong correlations to LGE.

4470.   24 Assessment of diffuse ventricular fibrosis in atrial fibrillation using extracellular volume fraction mapping: initial study
Lei Zhao1, Xiaohai Ma1, Songnan Li2, Tianjing Zhang3, Jing An3, Greiser Andreas4, and Zhanming Fan1
1Radiology, Anzhen Hospital, Capital Medical University, Beijing, Beijing, China, 2Cardiology, Anzhen Hospital, Capital Medical University, Beijing, Beijing, China, 3MR Collaborations NE Asia, Siemens Healthcare, Beijing, China, Beijing, China, 4Siemens Healthcare, Erlangen, Germany

Unlike focal fibrosis, diffuse myocardial fibrosis is not visualized on delayed enhancement magnetic resonance imaging (MRI), but can be quantified with extracellular volume fraction (ECV) mapping. In atrial fibrillation (AF), it may be induced by arrhythmia or reflect pre-existing cardiomyopathy. Ten subjects (8 persistent AF patients and 2 controls) underwent cardiac MR examination which included T1 mapping sequence. Our results reveal that ECV mapping identifies diffuse LV fibrosis in patients with AF.

Thursday 4 June 2015
Exhibition Hall 10:30 - 11:30

  Computer #  
4471.   
25 Efficient Radial Tagging: Undersampled Radial Acquisition with Polar Fourier Transform Reconstruction
Shokoufeh Golshani1 and Abbas Nasiraei Moghaddam1,2
1BME, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Tehran, Iran, 2Radiology, UCLA, Los Angeles, CA, United States

In radial tagging, the information of taglines required for strain imaging is located on a donut shaped region in k-space that can be collected efficiently through radial sampling sequence. In this study, we investigated the efficiency of radial data acquisition for strain imaging in conjunction with an adapted PFT reconstruction algorithm; a Hankel-based transform used for polar data. Both phantom and human images showed high robustness of PFT reconstruction against reduced number of radial data lines. This can be exploited towards real-time imaging, which is necessary in some cardiac assessments such as stress test. In addition, its implementation is adequately fast for in-line reconstruction.

4472.   26 Assessment of Global Cardiac Function from Tagged Magnetic Resonance Images. Comparison with Cine MRI
Abram Makram1, Ayman Khalifa1, Hossam El-Rewaidy2, Ahmed Fahmy2, and El-Sayed H. Ibrahim3
1Helwan University, Cairo, Egypt, 2Nile University, Cairo, Egypt, 3University of Michigan, Ann Arbor, MI, United States

Quantification of the global cardiac function from the tagged images is challenging due to the anatomy obstruction by the taglines and low myocardium-to-blood contrast. In this work, a method is presented for customized tagline removal and improving myocardium-to-blood contrast. The proposed method is applied on images from 12 patients to calculate global cardiac functional parameters and compare them to those from cine images. The results show that the proposed method can be used to accurately estimate ventricular volume and mass, which would allow for reduced scan-time through measuring both regional and global cardiac function parameters from one set of images.

4473.   27 Impact of temporal resolution on the quantification of regional myocardial velocities using tissue phase mapping
Kai Lin1, Robert A Gordon2, Keith H Benzuly2, Clyde W Yancy2, Jon W Lomasney2, Vera H Rigolin2, Allen S Anderson2, Michael Markl1, and James C Carr1
1Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL - Illinois, United States, 2Cardiology, Northwestern University Feinberg School of Medicine, Chicago, IL - Illinois, United States

Our findings suggest that tissue phase mapping with low temporal resolution may serve as an alternative in quantifying cardiac motion for subjects who can not hold the breath for a long time.

4474.   28 Multi-slice Excitation with MRI Tagging for Single Breath hold Estimates of Left Ventricular Rotational Mechanics
Zhe Wang1,2, Ziwu Zhou1,2, Yi Wang3, Peng Hu1,2, and Daniel B. Ennis1,2
1Radiological Science, University of California, Los Angeles, CA, United States, 2Bioengineering, University of California, Los Angeles, CA, United States,3Neurology, University of California, Los Angeles, CA, United States

Current clinical protocols for measuring LV twist require two separate breath holds to acquire tagged images at the LV apex and LV base, which subjects estimates of LV twist to breath hold differences. Multi-slice excitation (CAIPIRINHA) permits combining these two acquisitions into a single scan. We implemented the CAIPIRINHA technique with a tagging sequence, acquired data in five healthy volunteers, and compare the results with traditional two breath-hold LV twist results. Linear regression shows a high correlation between the two (r=0.99) and LV twist Bland-Altman result shows a small bias of 0.21° with narrow 95% confident intervals of [-0.47°, 0.89°].

4475.   
29 Improvement of Left Ventricular Strain with Reduction of Mean Pulmonary Arterial Pressure in Pulmonary Hypertension: Treatment Effect Independent of Right Ventricular Volumetric Parameters.
Tomoyoshi Kimura1,2, Hideki Ota1, Koichiro Sugimura3, Kazuomi Yamanaka1, Tatsuo Nagasaka1, Hiroaki Shimokawa3, Kei Takase1, and Haruo Saito2
1Radiology, Tohoku University Hospital, Sendai, Miyagi, Japan, 2Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan, 3Cardiology, Tohoku University Hospital, Sendai, Miyagi, Japan

We enrolled 11 patients with chronic thromboembolic pulmonary hypertension and one with idiopathic pulmonary arterial hypertension. Biventricular function and left ventricular (LV) strain analyses were performed before and after treatment. MR-derived parameters of cardiac functions were compared with mean pulmonary arterial pressure (mPAP). All patients demonstrated normal LV ejection fraction at baseline. Right ventricular (RV) end-systolic and end-diastolic volume index were correlated with mPAP at baseline; none of the strain parameters were correlated. However, improvements of circumferential and radial strain in inferolateral segment as well as RV end-systolic volume index were independently correlated with reduction of mPAP.

4476.   30 A Novel Approach to Comprehensive Atrio-Ventricular Functional Analysis
Xiaoxia Zhang1,2, Nikhil Jha1,2, Himanshu Gupta3, Nouha Salibi2,4, and Thomas Jr. Denney1,2
1Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, United States, 2AU MRI Research Center, Auburn University, Auburn, AL, United States, 3Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL, United States, 4MR R&D, Siemens Healthcare, Malvern, PA, United States

Cardiac MRI provides important structural and functional information. However routine quantitative analysis of cine MRI is often restricted to left and right ventricular ejection fraction measurements. Functional assessment of left and right atria is frequently not performed. In this abstract, we present an image acquisition and analysis framework for comprehensive evaluation of all cardiac chambers simultaneously, which leverages limited human input to optimize quantitative functional output and allows for evaluating bi-atrial and biventricular interactions simultaneously that may be important in various disease states.

4477.   31 Normalized Wall Thickening Patterns for Detecting Cardiac Functional Abnormality from Cine MRI Images
Mai Wael1, El-Sayed H. Ibrahim2, and Ahmed Fahmy1
1Nile University, Cairo, Egypt, 2University of Michigan, Ann Arbor, MI, United States

A method is presented for detecting regional wall motion abnormality based on capturing the variation in myocardial thickness during the cardiac cycle from standard cine MRI images. The extracted wall thickness patterns are normalized relative to the average epicardial radius, mapped to lower dimensions using principal component analysis, and then classified into normal or abnormal using the maximum likelihood criterion with leave-one-out method. The developed method provides automatic assessment of regional abnormality for each segment in each slice; therefore, it could be a valuable tool for automatic and fast determination of regional wall motion abnormality from conventional untagged cine images.

4478.   32 Left Ventricular (LV) volume based indices for the evaluation of diastolic function using high frame rate cine SSFP imaging: Direct comparison with Doppler Echocardiography
Jiming Zhang1, Amol Pednekar2, Jie Chen1, Claudio Arena1, Debra Dees1, Benjamin Cheong1, and Raja Muthupillai1
1Diagnostic and Interventional Radiology, CHI St Luke's Health, Houston, TX, United States, 2Philips Healthcare, Houston, TX, United States

Fifty percent of the heart failure patients have diastolic dysfunction with preserved ejection fraction (HFpEF), and traditionally echocardiography is used for evaluating diastolic dysfunction due to its superior temporal resolution. We propose LV volume based metrics as a MR based index that is comparable to conventional echo based index for the evaluation of diastolic dysfunction. The results from this pilot study suggest that it is feasible to evaluate both systolic and diastolic function with a single set of high-temporal resolution cine SSFP images acquired during free breathing.

4479.   33 Free Breathing Variable Flip Angle Balanced SSFP Cardiac Cine Imaging with Reduced SAR at 3T
Subashini Srinivasan1,2, Randall M Kroeker3, Adam Plotnik1, Simon Gabriel1, Nancy Halnon4, Peng Hu1, J. Paul Finn1, and Daniel B Ennis1,2
1Department of Radiological Sciences, University of California, Los Angeles, California, United States, 2Department of Bioengineering, University of California, Los Angeles, California, United States, 3Siemens Healthcare, Malvern, Pennsylvania, United States, 4Department of Pediatrics, University of California, Los Angeles, California, United States

Breath-hold, segmented, constant flip angle (BH-CFA) bSSFP cardiac cine imaging can be challenging at 3T in patients with poor breath holding capacity which results in motion artifacts. Real-time, free-breathing imaging with retrospective reconstruction can be SAR intensive, which may limit image quality. The objective of this study was to develop and evaluate a free breathing variable FA (FB-VFA) cardiac cine imaging technique with reduced SAR at 3T for improved comfort and compliance. FB-VFA reduced the SAR by 25% compared to BH-CFA and maintained blood-myocardium contrast and image quality sufficient to perform global and regional cardiac functional analysis.

4480.   
34 Robust Free-Breathing Whole-Heart Cine MRI using Multi-Slab 3D Acquisition with Isotropic Resolution and Offline Reformattability
Peng Lai1, Joseph Y Cheng2, Shreyas S Vasanawala2, and Anja CS Brau3
1Global MR Applications & Workflow, GE Healthcare, Menlo Park, CA, United States, 2Radiology, Stanford University, CA, United States, 3Global MR Applications & Workflow, GE Healthcare, Munich, Germany

Conventional 2D cine requires long scan time and is not reformattable. Breathhold 3D cine suffers from reduced contrast and increased SSFP banding artifacts. This work developed a novel technique for free-breathing whole-heart cine imaging. Our results show that this new method is more robust than breathhold 3D cine and enables 3D imaging with isotropic resolution and thus offline reformatting.

4481.   35 Can we rely on the new 1T “benchtop” systems for investigating cardiac function and viability?
Daniel James Stuckey1, Thomas A Roberts1, Laurence H Jackson1, Rajiv Ramasawmy1, Valerie Taylor1, Anna L David2, Bernard Siow*1, and Mark F Lythgoe*1
1Centre for Advanced Biomedical Imaging, UCL - University College London, London, United Kingdom, 2Institute for Women’s Health, UCL - University College London, London, United Kingdom

We show for the first time that 1T “benchtop” MRI can assess myocardial viability as well as contraction in a rat model of myocardial infarction. Results compared well with high field MRI and ultrasound. Although the speed with which ultrasound acquisitions can be acquired make it an effective choice for rapidly measuring cardiac contractility, the ability of MRI to rapidly quantify infarct size using late gadolinium enhancement, as well as RV function, demonstrates that low field MRI systems can provide essential information beyond what is possible from ultrasound, making it a valuable tool for studying experimental myocardial infarction and therapy.

4482.   36 Evaluation of Myocardial Eulerian Strain Using Bandpass Optical Flow. Comparison to Harmonic Phase Imaging
Azza Hassanein1, Ayman Khalifa1, and El-Sayed H. Ibrahim2
1Helwan University, Cairo, Egypt, 2University of Michigan, Ann Arbor, MI, United States

HARP is a commonly used technique for analyzing tagged images. Nevertheless, HARP tracking of the material points fails near the myocardial boundaries. Band-Pass Optical Flow (BPOF) is a motion analysis technique that, similar to HARP, is based on k-space analysis, but enforces optical flow constraints, which could provide a remedy to the HARP limitation. The purpose of this work is to use BPOF for calculating strain from tagged images, and compare the results to HARP at different myocardial regions based on numerical phantom and in-vivo images. The results show that BPOF is superior to HARP in tracking boundary taglines.

4483.   37 Heterogeneity of Myocardial ATP Flux Rate via CK In Vivo Porcine Hearts with hiPSC Tri-lineage Cell Transplantation Using 2D CSI P-31 MR Spectroscopy
Weina Cui1, Lei ye1, Albert Jang1, Pengyuan Zhang1, Qiang Xiong1, and Jianyi Zhang1
1Department of Medicine/cardiology, University of Minnesota, minneapolis, MN, United States

We investigated the functional impact of combined intramyocardial transplantation of cardiomyocytes, endothelial cells, and smooth muscle cells derived from hiPSCs to a porcine model of ischemia reperfusion (I/R). It was demonstrated that ATP turnover rate could be measured with two components, the creatine reaction rate and ATP hydrolysis rate, even without measuring Pi levels. MI injury has a heterogeneous effect on myocardial bioenergetics. The border zone PCr/ATP ratio is improved in the cell treated group compared with open patch group. The Kpcrright arrowATP in the border zone is slightly increased in cell treated group compared with patch only group.

4484.   38 High resolution quantitative spiral CMR perfusion imaging demonstrates a reduced endocardial to epicardial perfusion gradient and myocardial flow reserve in patients with microvascular disease - permission withheld
Michael Salerno1,2, Yang Yang3, Peter Shaw4, Angela Taylor4, Craig Meyer3, Fred Epstein3, and Christopher Kramer4,5
1Medicine, Cardiology, University of Virginia, Charlottesville, VA, United States, 2Radiology, University of Virginia, Charlottesville, VA, United States,3Biomedical Engineering, University of Virginia, VA, United States, 4Medicine, Cardiology, University of Virginia, VA, United States, 5Radiology, University of Virginia, VA, United States

Patients with non-obstructive coronary artery disease may have abnormal myocardial perfusion reserve (MPR) resulting from microvascular disease (MVD). Reduced MPR as demonstrated by PET is a significant predictor of cardiac death. CMR has the unique ability to quantify transmural differences in perfusion given its high spatial resolution providing new insights into MVD. We developed a high resolution (1.5mm) quantitative spiral perfusion pulse sequence and performed vasodilator stress in patients with a high likelihood of MVD. We demonstrate an abnormal stress endocardial to epicardial perfusion gradient as well as abnormal MPR in these patients.

4485.   39 Prospectively Accelerated CMR First-pass Perfusion Imaging in Patients with Suspected Heart Disease
Xiao Chen1, Michael Salerno2,3, Christopher M. Kramer3,4, Bhairav B. Mehta1, Yang Yang1, Peter Shaw4, 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, VA, United States, 4Medicine, Cardiovascular Medicine, University of Virginia, Charlottesville, VA, United States

First-pass cardiac perfusion MRI demands fast imaging techniques to achieve high spatial resolution and coverage within a small acquisition window. We recently developed a CS method BLOSM to accelerate first-pass perfusion with respiratory motions, and demonstrated the advantages of BLOSM using retrospectively-undersampled first-pass data. In the present study, we aimed to evaluate prospectively-accelerated BLOSM first-pass images in patients with suspected heart disease. Using prospectively accelerated data, BLOSM showed improved reconstruction quality compared to k-t SLR. BLOSM may provide clinically acceptable image quality at higher acceleration rates such as 6, even with the presence of respiratory motion.

4486.   40 A Novel Fully Automatic Motion Correction Scheme for Cardiac Perfusion MR Images Using Group-wise Non-rigid Registration
Sandeep Kaushik1, Dattesh Shanbhag1, Anne Menini2, Sheshadri Thiruvenkadam1, Stephanie Reiter3, Tobias Heer3, Günter Pilz3, and Anja Brau4
1Medical Image Analysis Lab, GE Global Research, Bangalore, Karnataka, India, 2GE Global Research, Garching, Bavaria, Germany, 3Department of Cardiology, Clinic Agatharied Academic Teaching Hospital, University of Munich, Hausham, Bavaria, Germany, 4GE Healthcare, Garching, Bavaria, Germany

Cardiac perfusion MRI (PWI) scans are typically riddled with heart motion due to scan times too long for breath hold. Non-rigid registration (NRR) algorithms are often used for motion correction. In this work, a group-wise NRR algorithm for motion correction of cardiac PWI images is proposed. Signal intensity variations due to contrast flow can potentially distort and introduce undesirable intensity changes in NRR output. This has been addressed using an intensity normalization scheme. Temporal filter post-processing has been used to eliminate the residual motion. Resulting contrast curves demonstrate time course conformity as validated against ground truth contrast curves.

4487.   41 FLASH Proton Density Imaging for Improved Surface Coil Intensity Correction in Quantitative and Semi-Quantitative SSFP Myocardial Perfusion Imaging
Sonia Nielles-Vallespin1, Peter Kellman1, Li-Yueh Hsu1, and Andrew E Arai1
1National Institutes of Health, Bethesda, MD, United States

Perfusion scans preceded by both FLASH and SSFP-PD frames from 10 patients with no myocardial infarction were analyzed semi-quantitatively and quantitatively. Low flip-angle SSFP protocol exhibited severe ghosting artifacts in 6 of 10 subjects. These artifacts lead to errors in quantitative perfusion maps and semi-quantitative perfusion indexes. They can be severe enough to cause false positives diagnoses. Using FLASH-PD frames as input for the surface coil intensity correction (SCIC) improved the homogeneity of perfusion measurements. Thus, FLASH PD images are recommended for SCIC of SSFP perfusion images in place of low flip angle SSFP PD images.

4488.   42 Radial CAIPIRINHA for rapid 6 slice myocardial perfusion without magnetization preparation
Haonan Wang1, Neal Kepler Bangerter1, Liyong Chen2, Ganesh Adluru3, and Edward V.R DiBella3
1Department of Electrical & Computer Engineering, Brigham Young University, Provo, Utah, United States, 2Advanced MRI Technologies, Sebastopol, California, United States, 3Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, Utah, United States

First-pass myocardial perfusion imaging offers a valuable method for characterizing the blood flow of the myocardial tissue. Much of the work in myocardial perfusion imaging has used saturation preparation and an ECG trigger. An alternative approach is to use a spoiled gradient echo (SPGR) steady-state acquisition that acquires images rapidly enough so that ECG gating is not needed. In 2D simultaneous multi-slice acquisition, we utilize the CAIPI technology to achieve whole heart coverage and combined that with interleaved slice acquisition, which increases the effective TR. In this study, we demonstrate that the ungated golden ratio radial CAIPI with interleaved acquisition provides reasonable CNR while providing whole heart coverage.

4489.   43 Data-driven dynamic coil-bias correction for segmented myocardial perfusion images.
Roman Wesolowski1,2, Eva Sammut2, Niloufar Zarinabad Nooralipour2, Eike Nagel2, and Amedeo Chiribiri2
1University of Birmingham, Birmingham, West Midlands, United Kingdom, 2King's College London, London, United Kingdom

Coil-bias most persistently contaminates cardiac magnetic resonance (CMR) imaging despite the vendors’ efforts in reducing its effects. Due to the heart’s shape and its oblique position in reference to the coil’s receiving element, perfusion abnormalities can often be disguised in the areas highly affected by this effect, which can reduce CMR’s diagnostic capabilities. Although proton density-based solutions have been in practice, we propose a data-driven dynamic coil-bias correction (DCBC) algorithm for segmented myocardial perfusion. DCBC does not require additional scans and can be applied retrospectively. We show that it significantly reduces the effect of coil-bias, superseding proton density-based technique.

4490.   44 A preliminary assessment of magnetic resonance low-multi-b values diffusion weighted imaging in patients with hypertrophic cardiomyopathy
Mou anna1, Li zhiyong2, Zhang ziheng3, Song qingwei2, and Liu ailian2
1The First Affiliated Hospital of Dalian Medical University, China, Liaoning, China, 2The First Affiliated Hospital of Dalian Medical University, Liaoning, China,3GE Healthcare China, Beijing, China

Microvascluar perfusion abnormality and ischemia condition could be an important risk factor for the clinical assessment of hypertrophic cardiomyopathy(HCM). We preliminarily investigate the difference of myocardial microvascluar perfusion between HCM patients and normal volunteers with low-multi-b values(0,20,50,100,200 s/mm2) diffusion weighted imaging. We found that the measurement parameters reflected microvasluar perfusion (Standard ADC, Slow ADC, Fast ADC and fraction of Fast ADC value)in HCM patients were significant lower than that of normal volunteers. We conclude that low-multi-b values diffusion weighted imaging could quantitatively and noninvasively evaluate the perfusion status in HCM patients .

4491.   45 Fusion and combined evaluation of 3D-CMR-perfusion with 3D-MR-coronary angiography - permission withheld
Alexander Gotschy1,2, Lukas Wissmann1, Datta Singh Goolaub1, Markus Niemann3, Sebastian Kozerke1, and Robert Manka1,3
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland, 3Department of Cardiology, University Hospital Zurich, Switzerland

The most relevant parameters for the assessment of coronary artery disease are myocardial perfusion and the status of the coronary arteries. Therefore, the aim of our study was to investigate the feasibility and potential added value of MR-based hybrid imaging by the combined assessment and fusion of 3D-MR coronary angiography (MRCA) with a 3D-CMR-perfusion sequence. We found that the combined evaluation had superior sensitivity at the cost of a loss in specificity when compared to CMR-perfusion alone in a vessel-based approach. Furthermore in the fused images, coronary stenosis could be matched with perfusion deficits in different myocardial layers.

4492.   46 Heart-Rate Independent, Whole-Heart, Free-Breathing, Quantitative Myocardial BOLD MRI at 3T with Simultaneous 13N-Ammonia PET Validation in Canines - video not available
Hsin-Jung Yang1, Damini Dey2, Jane Sykes3, John Butler3, Avinash Kali2, Ivan Cokic2, Behzad Sharif2, Sotirios Tsaftaris4, Debiao Li2, Piotr Slomka2, Frank Prato3, and Rohan Dharmakumar2
1Cedars Sinai Medical Center, Los angeles, CA, United States, 2Cedars Sinai Medical Center, CA, United States, 3Lawson Health Research Institute, ON, Canada, 4IMT Lucca Institute, Lucca, Italy

Myocardial BOLD MRI is an emerging non-contrast approach for assessing ischemic heart disease. Current myocardial BOLD methods are limited by poor spatial coverage, heart-rate dependency and image artifacts (e.g. coil bias, B1 and B0 inhomogeneities). To overcome these limitations, we developed a heart-rate independent, fast, free breathing 3D T2 mapping technique at 3T that utilizes near perfect imaging efficiency. This quantitative BOLD approach, which can be performed within 3 minutes, permits full LV coverage during pharmacological stress. In this study, we tested our approach in a canine model and validated our findings with simultaneously acquired 13N-ammonia PET perfusion data in a clinical PET-MR system.

4493.   47 Reducing Dark-Rim Artifacts in Free-Breathing First-Pass Perfusion Cardiac MRI With Cartesian Sampling and Instantaneous Image Reconstruction
Zhengwei Zhou1,2, Xiaoming Bi3, Hsin-Jung Yang1,2, Rohan Dharmakumar1, Reza Arsanjani1,4, C Noel Bairey Merz4, Daniel Berman1,4, Debiao Li1,2, and Behzad Sharif1
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States, 3MR R&D, Siemens Healthcare, Los Angeles, CA, United States, 4Cedars-Sinai Heart Institute, Los Angeles, CA, United States

Conventional first-pass myocardial perfusion MRI methods are prone to dark-rim artifacts. We developed a free-breathing DRA-reduced FPP scheme with Cartesian k-space sampling and instantaneous “online” image reconstruction. This can be implemented into clinical routine, enhancing its clinical accessibility. Preliminary results of canine with myocardial infarction showed high accuracy compared to late gadolinium enhancement imaging.

4494.   48 Through-plane dark-rim artefacts in 3D first-pass perfusion
Merlin J Fair1,2, Peter D Gatehouse1,2, and David N Firmin1,2
1NHLI, Imperial College London, London, United Kingdom, 2NIHR Cardiovascular BRU, Royal Brompton Hospital, London, United Kingdom

Whilst dark-rim artefacts have been studied in 2D first-pass perfusion, they could also have the potential to be produced in the through-plane direction of 3D first-pass perfusion due to the typically coarse resolution employed in the second phase-encoding direction. An examination of the potential for this Gibbs truncation effect, and its relationship to the also troubling partial-volume effect, is studied in conical and anatomical numerical phantoms as well as a representative in-vivo dataset.

Thursday 4 June 2015
Exhibition Hall 10:30 - 11:30

  Computer #  
4495.   49 Improving flow characterization in SNAP with k-space acquisition reordering
Jinnan Wang1, Haining Liu2, Zechen Zhou3, Niranjan Balu2, Thomas S Hatsukami2, Jin Liu2, Peter Boernert4, and Chun Yuan2
1Philips Reserach North America, Seattle, WA, United States, 2University of Washington, Seattle, WA, United States, 3Tsinghua University, Beijing, China,4Philips Research Europe, Hamburg, Germany

Simultaneous Non-contrast Angiography and intraPlaque hemorrhage (SNAP) imaging was proposed as a technique for joint MRA and high risk atherosclerotic plaque feature (intraplaque hemorrhage, or IPH) detection. For carotid artery imaging, to achieve ideal MRA, an inversion coverage of 60cm is desired but can’t be afforded by most scanners due to the bore length limitation. As a result, flow artifacts can be occasionally observed on the carotid SNAP MRA images. To address this issue, a new SNAP acquisition scheme is proposed to improve the MRA performance by optimizing k-space acquisition ordering so that flow artifacts can be minimized.

4496.   50 Non-contrast-enhanced peripheral venography using velocity-selective magnetization preparation and transient balanced SSFP
Taehoon Shin1, Seth J Kligerman1, Robert S Crawford2, Sanjay Rajagopalan3, and Rao P Gullapalli1
1Radiology, University of Maryland, Baltimore, MD, United States, 2Vascular Surgery, University of Maryland, MD, United Kingdom, 3Cardiovascular Medicine, University of Maryland, Baltimore, MD, United States

A non-contrast-enhanced peripheral MR venography method is proposed which generates high-contrast 3D venograms directly using a single acquisition. The proposed method combines velocity-selective magnetization preparation for suppressing arterial signal and transient balanced SSFP readout for suppressing muscle signal. The sequence parameters are optimized to maximize vein-to-background contrast and validated in vivo. The feasibility of visualization of the entire peripheral venous systems using multi-station is demonstrated in healthy subjects.

4497.   51 Non-contrast MRA in PAD Patients: Diagnostic Comparison of QISS, ECG-FSE, and QIR Techniques
Christopher J Hanrahan1, Marc Lindley1, Michelle Mueller2, Daniel Sommers1, Marta E Heilbrun1, Glen Morrell1, Daniel Kim1, and Vivian S Lee1
1Radiology, UCAIR, University of Utah School of Medicine, Salt Lake City, Utah, United States, 2Vascular Surgery, University of Utah School of Medicine, Salt Lake City, United States

Non-contrast MRA techniques using QISS, QIR, and ECG-gated FSE were compared among 3 stations in peripheral arterial disease patients at 3 Tesla using gadolinium enhanced MRA as the standard.

4498.   52 Comprehensive arterial assessment in diabetic patients using combined quiescent interval single shot (QISS) imaging for leg imaging and QISS-arterial spin labeled MRA for pedal imaging: preliminary experience with comparison to DSA
Ruth P Lim1,2, Adrienne CY Lam1, Matthew Lukies1, Dinesh Ranatunga1, Emma K Hornsey1, Brenden McColl1, Yuliya Perchyonok1,2, Jason Chuen2,3, Jason Heidrich1, Pei-Heng Ko3, and Robert R Edelman4
1Radiology, Austin Health, Melbourne, Victoria, Australia, 2The University of Melbourne, Melbourne, Victoria, Australia, 3Vascular Surgery, Austin Health, Melbourne, Victoria, Australia, 4Radiology, NorthShore University Health System, Chicago, IL, United States

Imaging peripheral arterial disease (PAD) in diabetic patients is challenging. We evaluate a combined QISS MRA and QISS arterial spin labeled MRA approach (cQISS MRA) for imaging from the infrarenal aorta to the pedal vessels in 15 diabetic patients with symptomatic PAD, using digital subtraction angiography as the reference standard. High diagnostic confidence was observed for cQISS-MRA, however this was significantly lower in the foot compared to more proximal regions. 74.7% sensitivity and 86.8% specificity for hemodynamically significant (≥50%) stenosis was observed overall, with highest sensitivity and specificity for the pelvic region, and poor specificity (50%) for the pedal region.

4499.   53 Comparison of 3D non-contrast enhanced foot MR angiography using steady-state free precession with single and multi-directional FSD modules preparation
Na Zhang1,2, Zhaoyang Fan3, and Xin Liu1,2
1Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology of Chinese Academy of Sciences, Shenzhen, Guangdong, China, 2Shenzhen Key Laboratory for MRI, Shenzhen, Guangdong, China, 3Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States

Three-dimensional (3D) non-contrast enhanced MR angiography (NCE-MRA) using flow-sensitive dephasing (FSD) prepared steady-state free precession (SSFP) had proved a promising strategy for evaluation of peripheral vasculature without the use of gadolinium-based contrast agent. The magnetization preparation with FSD gradients was used for the blood signal suppression with advantages of flow-independence. It could be flexibly configured in both direction and strength so that multidirectional flow suppression was feasible. The purpose of this study was to compare the image quality of pedal arteries acquired from the NCE-MRA technique with single directional and two-directional FSD modules preparation, respectively.

4500.   54 Velocity-Selective Magnetization-Prepared Non-Contrast-Enhanced Cerebral MR Angiography at 3T
Qin Qin1,2, Taehoon Shin3, Michael Schar1, Hua Guo4, and Ye Qiao1
1Radiology, Johns Hopkins University, Baltimore, Maryland, United States, 2Kirby Center, Kennedy Krieger Institute, Baltimore, Maryland, United States,3Radiology, University of Maryland, Baltimore, Maryland, United States, 4Center for Biomedical Imaging Research, Biomedical Engineering, Tsinghua University, Beijing, China

The new velocity-selective saturation (VSS) pulse train, by embedding a pair of composite pulses for refocusing in each k-segment and phase cycling applied over consecutive k-segments, offers improved robustness to B0/B1 inhomogeneity in the brain at 3T. Velocity-selective magnetization-prepared non-contrast-enhanced cerebral MR angiography was demonstrated on healthy volunteers. Compared with TOF MRA, VSS prepared MRA depicted more distal branches of cerebral arteries and allowed for the whole-brain coverage without the requirement of section positioning orthogonal to the direction of flow.

4501.   55 Velocity-selective magnetization-prepared non-contrast-enhanced peripheral MR angiography at 3T
Taehoon Shin1, Qin Qin2, Jang-Yeon Park3, and Sanjay Rajagopalan4
1Diagnostic Radiology, University of Maryland, Baltimore, MD, United States, 2Radiology, Johns Hopkins University, Baltimore, MD, United States, 3Biomedical Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do, Korea, 4Cardiology, University of Maryland, Baltimore, MD, United States

While velocity-selective (VS) magnetization-prepared non-contrast-enhanced MR angiography has shown great promise at 1.5T with advantages of non-subtractiveness and large 3D FOV, its feasibility at 3T remains questionable due to the sensitivity of VS excitation to B0 and B1 inhomogeneities. In this study, we present an updated version of VS-MRA pulse sequence which employs paired refocusing for reducing the sensitivity to B0 and B1 offsets and double VS preparations for removing stripe artifacts caused by imperfect refocusing. The feasibility of the proposed method is shown in a healthy subject.

4502.   56 3D TOF MR Angiography using Combined Compressed Sensing and Parallel Imaging with Coil Compression
Naoyuki Takei1, Kevin F. King2, Adriana Kanwischer2, and Hiroyuki Kabasawa1
1GE Healthcare, Hino, Tokyo, Japan, 2GE Healthcare, WI, United States

3D TOF MR Angiography is an established clinical routine application. Scan time saving is important for brain routine that is frequently used in MRI scan in the world. Compressed sensing (CS) is a promising technique to accelerate scanning for high imaging contrast that has sparse image. In this work, the combination of CS and parallel imaging (PI) was applied to 3D TOF and demonstrated feasible. Volunteer scan was performed compared with PI only in brain. The CS +PI sequence reduced scan time by 43 % identifying the main and distal arteries. In conclusion, CS provides equivalent image quality with less scanning time than PI only.

4503.   57 Additive value of Non Contrast MRA for evaluation of Mesenteric Arterial Anatomy in Preoperative Planning for Living Donor Liver Transplants.
Elizabeth M Hecht1, Firas Ahmed1, Anuradha Shenoy-Bhangle1, Guillermo Jimenez1, Stuart Bentley-Hibbert1, and Martin Prince1
1Columbia University, New York, NY, United States

This study was performed to assess the additive value of non-contrast enhanced MRA (NC-MRA) using a respiratory gated 3D SSFP based sequence for evaluation of liver arterial anatomy in patients under going contrast enhanced MRA (Gd-MRA) for preoperative planning for potential liver donation. Liver donor arterial anatomy evaluation is not significantly improved by the addition of NC-MRA but can be useful when GD-MRA is suboptimal and further improvements in sequence design would be helpful to limit contrast exposure in this population and increase efficiency of patient throughput.

4504.   58 Undersampled Motion Compensated LOST Reconstruction for Free-Breathing Coronary MRA
Andrew Peter Aitken1, Mehmet Akçakaya2, Rene Botnar1, and Claudia Prieto1
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, London, United Kingdom, 2Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United Kingdom

A highly accelerated 100% scan efficiency reconstruction approach for whole-heart coronary MRA is proposed. This approach achieves 100% scan efficiency by estimating the motion from an interleaved golden radial image navigator. Further acceleration is achieved by undersampling the MRA acquisition using a golden-step spiral-like Cartesian acquisition and the low dimensional structure self-learning and thresholding (LOST) reconstruction. This LOST-motion corrected approach leads to slightly reduced image quality in comparison to that of an ~8 times longer scan time navigator-gated approach.

4505.   59 Large Slice FOV Non-Contrast MR Angiography with Variable Slice Resolution 3D Time-of-Flight
Yutaka Nattsuaki1, Xiaoming Bi1, Aurelien F Stalder2, and Gerhard Laub1
1Siemens Healthcare, Los Angeles, CA, United States, 2Siemens Healthcare, Erlangen, Germany

Robust but slow 3D Time-of-flight (TOF) MR angiography has its practical limitation in slice FOV coverage. Recent advancements in MRI acceleration with TOF sequences (e.g. TOF with sparse undersampling) can resolve this practical limitation, and large slice FOV coverage TOF may be realized. Not only for the larger coverage, extra time savings can be reinvested in slice resolution for better delineation of small arteries. The current work introduces the variable slice resolution TOF, a novel concept that adjusts slice resolutions according to anatomical needs for the optimal large FOV TOF within clinically acceptable scan time (<10 min.).

4506.   60 Image quality and accuracy of a 3D whole-heart self-navigated sequence in comparison with cardiac computed tomography for the assessment of coronary artery anomalies
Giuseppe Muscogiuri1,2, Akos Varga-Szemes1, U. Joseph Schoepf1, Carlo N De Cecco1,2, Davide Piccini3,4, Wolfgang G Rehwald5,6, Anthony M Hlavacek1, and Arni C Nutting1
1Medical University of South Carolina, Charleston, SC, United States, 2University of Rome Sapienza, Rome, Italy, 3Siemens Healthcare IM BM IP, Lausanne, Switzerland, 4University of Lausanne, Lausanne, Switzerland, 5Siemens Medical Solutions, Chicago, IL, United States, 6Duke Cardiovascular Magnetic Resonance Center, Durham, NC, United States

In this project we compared a prototype non-contrast free-breathing self-navigated 3D (SN3D) whole-heart MRA acquisition and coronary CTA for the evaluation of the proximal course of coronary arteries in a pediatric patient population. Evaluation of image quality according to a 4-grade scale (1, non-diagnostic; 2, sufficient; 3, good; 4, excellent) and the visualization of the left main, left anterior descending, circumflex, first diagonal, posterior descending, and right coronary arteries were performed, in both techniques, by two experienced observers. Our preliminary results indicate that the non-contrast free-breathing SN3D MRA acquisition allows for the evaluation of coronary artery anatomy with similar image quality to cCTA without any radiation or administration of contrast agent.

4507.   61 ECG Gated 3D Single Shot Fast Spin Echo with Variable TR for Non-Contrast Peripheral MR Angiography at 3T
Xiangzhi Zhou1, Cheng Ouyang1, Aiming Lu1, and Mitsue Miyazaki1
1Toshiba Medical Research Institute USA, Vernon Hills, IL, United States

In conventional subtraction based non-contrast ECG gated 3D single shot fast spin echo (SSFSE) technique, each slice encoding and the followed echo train are played in a fixed TR (TR=n*RR). Ideally, TR should be sufficiently long for the recovery of the longitudinal magnetization of blood and background tissue, which led to a long scan time. In this work, a variable TR (vTR) method is proposed to reduce the scan time while still maintain the blood signal. The results showed the vTR method can significantly reduce scan time by 20-40% and had comparable arterial image quality as the fixed TR scan.

4508.   62 High-resolutional visualization of the lenticulostriate artery: Application of compressed sensing for faster acquisition
Tomohisa Okada1, Koji Fujimoto1, Yasutaka Fushimi1, Akira Yamamoto1, Kei Sano2, Toshiyuki Tanaka2, Naotaka Sakashita3, and Kaori Togashi1
1Dept. of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Kyoto, Japan, 2Department of Informatics, Kyoto University Graduate School of Informatics, Kyoto, Kyoto, Japan, 3Toshiba Medical Systems, Otawara, Tochigi, Japan

Visualization of the lenticulostriate artery (LSA) using TOF-MRA requires high resolution and takes long acquisition time, which might be mitigated by under-sampling and compressed sensing (CS) reconstruction. However, application of CS to small structures such as LSA is yet to be investigated. CS-reconstructed images of 25, 50 and 75% data were compared with the full-sampled images in 11 volunteers. Under-sampling of 75% data was comparable to the control, but visualization was impaired at 50% and 25%. Higher contrast between LSA and background, as well as improved CS reconstruction, would be required for LSA visualization.

4509.   63 Turbo quiescent-interval single-shot (TurboQISS): accelerated non-enhanced peripheral angiography
Shivraman Giri1, Eugene Dunkle2, Wei Li2, Ian Murphy2,3, Ioannis Koktzoglou2,4, and Robert R Edelman2,3
1Siemens Healthcare, Chicago, IL, United States, 2Radiology, NorthShore University HealthSystem, IL, United States, 3Radiology, Northwestern University Feinberg School of Medicine, IL, United States, 4Radiology, The University of Chicago Pritzker School of Medicine, IL, United States

Quiescent-interval single-shot (QISS) has proven to be an accurate and robust alternative to contrast-enhanced MRA and CT angiography for the evaluation of peripheral arterial disease, but scan time is longer than with these other imaging tests. In this work, we demonstrate a pulse sequence modification that cuts QISS scan time in half while maintaining image quality.

4510.   64 Combined parallel imaging and compressed sensing for rapid Inflow-enhanced Inversion Recovery (IFIR) imaging of carotid arteries - permission withheld
Allison Grayev1, Utaroh Motosugi1,2, Peter Bannas1,3, Naoyuki Takei4, Kevin King5, Kang Wang6, James Holmes7, Scott Reeder8,9, and Aaron Field1
1Department of Radiology, University of Wisconsin, Madison, WI, United States, 2Department of Radiology, University of Yamanashi, Yamanashi, Japan,3Department of Radiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany, Germany, 4Global MR Applications and Workflow, GE Healthcare, Hino, Japan, 5Global MR Applications and Workflow, GE Healthcare, Waukesha, WI, United States, 6Global MR Applications and Workflow, GE Healthcare, Madison, WI, United States, 7Department of Medical Physics, University of Wisconsin, Madison, WI, United States, 8Department of Radiology; Department of Medical Physics, University of Wisconsin, Madison, WI, United States, 9Department of Biomedical Engineering and Medicine; Department of Emergency Medicine, University of Wisconsin, Madison, WI, United States

Vascular imaging is an important step in the assessment of stroke; however, optimal evaluation of the neck vasculature often requires multiple sequences. The purpose of this study was to develop a non-contrast method of evaluating the carotid arteries from the aortic arch to skull base with excellent resolution in acceptable time parameters. Inflow-enhanced inversion recovery with fast spin echo readout (IFIR-FSE) was combined with parallel imaging and compressed sensing and compared to both contrast enhanced MRA and time-of-flight MRA in volunteer patients. After the image quality was optimized, patients were recruited to demonstrate feasibility in the clinical setting. 

4511.   65 Dietary intake enhances the visualization of MR portography using non-contrast-enhanced time-spatial labeling inversion pulse (Time-SLIP) - Evaluation of temporal change after meal to determine an appropriate examination timing -
Hiroki Matoba1, Akiyoshi Yamamoto1, Yuji Shintani1, Daiji Uchiyama1, Seigo Yoshida1, Katsumi Nakamura1,2, and Mitsue Miyazaki3
1Radiology, Tobata Kyoritsu Hospital, Kitakyusyu, Fukuoka, Japan, 2Radiology, Hikari Central Hospital, Hikari, Yamaguchi, Japan, 3Toshiba Medical Research Institute USA, Vernon Hills, Illinois, United States

We evaluate the visualization of sequential MR portography by using the Time-SLIP flow-in technique after food intake to determine an appropriate examination timing. MR portography was performed on 5 healthy volunteers at pre-meal, just after meal, 30 minutes after, 1 hour after, 2 hours after, 3 hours after, and 4 hours after. The visualization of extra- and intra-hepatic portal veins was significantly improved after food intake which increased portal venous flow, among which especially prominent at 1 to 2 hours after meal, which were thought to the appropriate timing to perform Time-SLIP flow-in portogrpahy rather than during the fasting period

4512.   66 Fat Saturation Improves Fresh Blood Imaging of Peripheral Vessels in the Calf Station
Marc D Lindley1,2, 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, 2Physics, University of Utah, Salt Lake City, Utah, United States

Fresh blood imaging (FBI) is based on subtraction of two acquisitions done at two different cardiac phases, by which the background signal cancels out. In clinical practice, however, we observe residual background signal after subtraction, which makes it challenging to visualize the vessels. In this study we sought to add fat saturation to FBI, in order to suppress better suppress background signal. We imaged eight patients with peripheral arterial disease using FBI with and without fat saturation, and our results show that FBI with fat saturation improves background suppression compared with FBI without fat saturation.

4513.   67 Velocity Selective Prepared Non-Contrast Enhanced MR Angiography using Phase Sensitive Reconstruction
Xinzeng Wang1, Joshua S Greer1,2, Shu Zhang1, and Ananth J Madhuranthakam1,3
1Radiology, UT Southwestern Medical Center, Dallas, Texas, United States, 2Bioengineering, UT Dallas, Dallas, Texas, United States, 3Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, Texas, United States

Velocity selective preparation (VSP) allows non-contrast enhanced MR angiography with minimal background signal in a single acquisition. However, the empirical velocity encoding used with VSP leads to venous signal contamination. In this work, we present a phase sensitive reconstruction combined with VSP that can determine the flow direction and can potentially differentiate arterial and venous signal with background signal suppression in a single acquisition. The proposed method successfully determined the flow direction in a flow phantom with good background suppression. The phase sensitive reconstruction also determined the flow direction in the popliteal artery of the lower leg in normal volunteers.

4514.   68 High resolution, first pass 3D gadolinium-enhanced venography of the jugular veins: application to multiple sclerosis
Andrew J. Walsh1, Derek J. Emery2, Ken Warren3, Ingrid Catz3, and Alan H. Wilman1
1Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada, 2Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Alberta, Canada, 3Neurology, University of Alberta, Edmonton, Alberta, Canada

First pass, 3D gadolinium-enhanced venography of the jugular veins is difficult to perform when seeking both large spatial coverage and high spatial resolution. Particularly when considering routine clinical 1.5 T systems that may not be equipped with dense phased arrays for parallel imaging, capturing the venous phase without overwhelming arterial enhancement becomes difficult. We test first pass Gd-enhanced venography encompassing a large 3D coronal field-of-view at 0.64 mm3 voxel dimensions using a single 36 sec acquisition. High resolution enables proper assessment of venous narrowing. We report on the feasibility in application to 60 subjects, 30 with multiple sclerosis (MS) and 30 healthy controls to examine cerebral venous drainage.

4515.   69 Positive contrast high-resolution 3D-cine imaging of the cardiovascular system in small animals using a UTE sequence and iron nanoparticles at 4.7, 7 and 9.4 T - permission withheld
Aurélien Julien Trotier1, William Lefrancois1, Kris Van Renterghem1, Jean-Michel Franconi1, Eric Thiaudière1, and Sylvain Miraux1
1RMSB-UMR5536, CNRS - Université de Bordeaux, Bordeaux, Aquitaine, France
 
To show that 3D sequences with ultra-short echo times (UTEs) can generate a positive contrast whatever the magnetic field (4.7, 7 or 9.4 T) and whatever Ultra Small Particles of Iron Oxide (USPIO) concentration injected and to use it for 3D time-resolved imaging of the murine cardiovascular system with high spatial and temporal resolutions. This approach might be useful to measure the functional cardiac parameters or to assess anatomical modifications to the blood vessels in cardio-vascular disease models.

4516.   70 The Effects of Injection Rate on Vascular Signal Intensity Profile in a Porcine Model using Four Gadolinium Contrast Agents: Comparison Between Observation and Prediction Based on Measured Blood Relaxivity Values
Jeffrey H Maki1, Guenther Schneider2, Alexander Massmann2, Matthias Leist2, Diane Wagner-Jochem2, and Gregory J Wilson1
1Radiology, University of Washington, Seattle, WA, United States, 2Radiology, University Hosptial of Saarland, Homburg, Germany

Eight juvenile swine were imaged with high temporal resolution (1.7 s) CE-MRA 3x each during the bolus passage of one of four Gd agents at 1,2,3 ml/sec (2 animals/agent, all single dose, 24 total injections). Simultaneous aortic blood sampling was performed (every 2 s) to measure actual Gd concentration. Ex vivo arterial blood was doped with each contrast agent to determine R1 and R2* vs. [Gd]. Predicted and actual signal intensity (SI) vs. time as well as bolus duration were compared, demonstrating a relatively flat SI response vs. injection rate, validating the benefit of slower Gd injections for CE-MRA.

4517.   71 An MRI-based CFD analysis of flow patterns in the jugular vein
Evan Kao1,2, Farshid Faraji1, Sarah Kefayati1, Van Halbach1, Matthew Amans1, and David Saloner1
1Radiology, UCSF, San Francisco, CA, United States, 2Bioengineering, UC Berkeley, Berkeley, CA, United States

We investigated the flow patterns in the jugular veins of two subject groups, one normal and one with suspected anamolies, using MRI-based CFD. Our results show that there are two types of venous geometries and flow patterns: (1) One which has helical flow in the jugular bulb (the junction between the sigmoid sinus and jugular vein), which results in a relatively straight flow in the jugular vein; (2) and another in which the jugular bulb is shaped such that it redirects flow at a right angle to the jugular vein, which creates pronounced helical flow pattern.

4518.   72 angioCEST: using TmDOTMA liposomes and chemical exchange saturation transfer for MR angiography
Todd C. Soesbe1,2, Ketan B. Ghaghada3, S. James Ratnakar1, Chandreshkumar Patel3, Mark Milne1, A. Dean Sherry1,4, and Robert E. Lenkinski2
1Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, Texas, United States, 2Department of Radiology, UT Southwestern Medical Center, Dallas, Texas, United States, 3Texas Children's Hospital, Houston, Texas, United States, 4Department of Chemistry, University of Texas at Dallas, Dallas, Texas, United States

Synopsis goes here.

Thursday 4 June 2015
Exhibition Hall 11:30 - 12:30

  Computer #  
4519.   1 Effect of BOLD Contrast on Myocardial Registration
Ilkay Oksuz1, Anirban Mukhopadhyay1, Marco Bevilacqua1, Hsin-Jung Yang2,3, Rohan Dharmakumar2,3, and Sotirios A. Tsaftaris1,4
1IMT Institute for Advanced Studies, Lucca, Tuscany, Italy, 2Biomedical Research Institute, Cedars Sinai Medical Center, Los Angeles, California, United States,3Medicine, University of California, Los Angeles, California, United States, 4Electrical Engineering and Computer Science, Northwestern University, Illinois, United States

Cardiac phase-resolved Blood-Oxygen-Level-Dependent (CP-BOLD) MRI is a new approach for detecting ischemia at rest. Currently disease assessment relies on segmental analysis and uses only a few images in the phase-resolved acquisition. It is expected that using all phases can permit pixel-level characterization of CP-BOLD MRI. In this study, state-of-the-art image registration techniques are evaluated on cardiac BOLD MRI data for the first time. The results show that cardiac phase-dependent variations in myocardial BOLD contrast in CP-BOLD images creates a statistically significant decrease in the accuracy compared to standard Cine MR images acquired under conditions of health and myocardial ischemia.

4520.   2 Three-dimensional Super-Resolution Technique for Whole-Heart Coronary MRA by Utilizing Graphical Processing Unit - permission withheld
Ryohei Nakayama1, Masaki Ishida1, Yasutaka Ichikawa1, Yoshitaka Goto1, Motonori Nagata1, Kakuya Kitagawa1, and Hajime Sakuma1
1Department of Radiology, Mie University School of Medicine, Tsu, Mie, Japan

A 3D SR technique was developed to improve image resolution and quality of whole-heart coronary MRA (WHCMRA) by utilizing GPUs. WHCMRA images with 0.6x0.6x0.75 mm resolution were reconstructed from the down-sampled WHCMRA images (1.2x1.2x1.5 mm) by using 3D SR technique, 2D SR technique and 3D bicubic interpolation. The computational time with 3D SR technique per patient considerably reduced from 4 h and 41.1 min to 45.5 min by the parallel implementation in GPUs. Root mean square error, structural similarity index and signal-to-noise ratio for 3D SR technique were 2.85, 0.984 and 65.8, being significantly greater than those for other two methods. The 3D SR approach would improve the diagnostic performance of WHCMRA for detection of stenosis.

4521.   3 Extracting a cine cardiac cycle without respiratory motion from real-time free-breathing images with unsupervised motion correction
Haris Saybasili1, Marie-Pierre Jolie2, and Bruce Spottiswoode1
1Siemens Healthcare, Chicago, Illinois, United States, 2Imaging and Computer Vision, Siemens Corporation, Corporate Technology, NJ, United States

Real-time free-breathing imaging methods are viable alternatives to conventional segmented cine imaging for patients that cannot hold their breath. However, heart-rate changes during real-time acquisitions result in a different number of phases per beat/slice. Methods of obtaining a predefined number of cardiac phases per beat/slice from real-time images has been shown previously. However, cardiac phases acquired during inconsistent respiratory phases are hard to analyze due to respiratory motion. In this work, we propose an unsupervised motion correction scheme to generate high SNR, single heart-beat breath-held (end expiration) cine images from any real-time free-breathing acquisition covering multiple heart-beats.

4522.   4 Software for multi-average processing in neonatal cardiac imaging
Andreia S. Gaspar1,2, David J. Cox1, Alan M. Groves1,3, and Anthony N. Price1
1Centre for the Developing Brain, King's College London, London, London, United Kingdom, 2Instituto de Biofisica e Engenharia Biomedica, Faculdade de Ciencias, Universidade de Lisboa, Lisboa, Lisboa, Portugal, 3Department of Pediatrics, Weill Cornell Medical College, New York, United States

Neonatal cardiac MRI presents significant challenges associated with subject size; cine sequences require multiple signal averages to increase SNR. However, when scanning unsedated, free-breathing infants, motion artefacts compromise individual averages and the resultant averaged dataset. We present a tool that rigidly registers averages, correcting motion displacement, before using intensity analysis to remove averages of poor image quality. Applying the software on neonatal cohort improved image quality leading to clearer definition of endo- and epicardial borders. Such post-processing of multi-average acquisitions could prove valuable in future trials using neonatal cardiac MRI.

4523.   5 Prediction of the Benefit of Motion-Compensated Reconstruction for Whole-Heart Coronary MRI - permission withheld
Jens Wetzl1,2, Christoph Forman3, Andreas Maier1,2, Joachim Hornegger1,2, and Michael O. Zenge3
1Pattern Recognition Lab, Department of Computer Science, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany, 2Erlangen Graduate School in Advanced Optical Technologies (SAOT), Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany, 3Siemens AG, Healthcare, Imaging & Therapy Systems, Magnetic Resonance, Erlangen, Germany

Respiratory motion represents a challenge in free-breathing whole-heart coronary MR angiograpy. For respiratory motion compensation, weighted iterative reconstruction aims to reconstruct a consistent sub-set of the acquired data. However, this may lead to increased sub-sampling artifacts. Motion-compensated (MoCo) reconstruction promises to overcome this by incorporating all acquired data using a motion model. Unfortunately, computation times are longer, and the resulting signal-to-noise ratio (SNR) improvement may not always justify this effort. This work proposes a method to predict the benefit of MoCo over weighted reconstruction directly after data acquisition. This prediction method was evaluated with in-vivo experiments in 15 volunteers.

4524.   6 Retrospective motion correction for carotid vessel wall imaging
Rui Li1, Shujing Cao1, Feng Huang2, and Chun Yuan1,3
1Center for Biomedical Imaging Research, Tsinghua University, Beijing, Beijing, China, 2Philips Research China, Shanghai, China, 3University of Washington, Seattle, Washington, United States

Carotid vessel wall magnetic resonance imaging (MRI) has been validated to discriminate different components in plaques and evaluate their vulnerability. Patient motion such as breathing and swallow is inevitable during acquisition. Navigator echo or self-gating techniques were explored by several previous works to monitor swallowing. However all these techniques are prospective methods and adopted accept/reject-reacquisition as their data management strategy, which interrupted data acquisition and prolonged scan duration. The target of this work is to develop a retrospective motion compensation method iteratively using a GRAPPA like convolution and optimized coil element data combination to preserve SNR during iteration.

4525.   7 Artifact Removal in Carotid Imaging based on Motion Measurement using Structured Light
Huijun Chen1, Jin Liu2, Zechen Zhou3, Chun Yuan2, Peter Boernert4, and Jinnan Wang5
1Tsinghua University, Beijing, Beijing, China, 2University of Washington, Seattle, WA, United States, 3Tsinghua University, Beijing, China, 4Philips Research Europe, Hamburg, Germany, 5Philips Reserach North America, Seattle, WA, United States

Motion induced artifact is a common cause of unsatisfactory image quality in carotid artery imaging: previous study found that motion was the most significant contributor to low image quality. Monitoring and quantifying motion in the neck area is more challenging than other body parts due to the complex non-rigid motion pattern. Structured light based motion detection system has been recently developed for MR. It was selected for neck based motion tracking in this study because of its capability in accurately measuring distance changes.

4526.   8 Data driven feature learning for representation of myocardial BOLD MR Images
Anirban Mukhopadhyay1, Marco Bevilacqua1, Ilkay Oksuz1, Rohan Dharmakumar2,3, and Sotirios Tsaftaris1,4
1IMT Institute for Advanced Studies Lucca, Lucca, LU, Italy, 2Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 3Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 4Electrical Engineering and Computer Science, Northwestern University, Evanston, Il, United States

Cardiac phase-dependent variations of myocardial signal intensities in Cardiac Phase-resolved Blood-Oxygen-Level-Dependent (CP-BOLD) MRI can be exploited for the identification of ischemic territories. This technique requires segmentation to isolate the myocardium. However, spatio-temporal variations of BOLD contrast, prove challenging for existing automated myocardial segmentation techniques, because they were developed for acquisitions where contrast variations in the myocardium are minimal. Appropriate feature learning mechanisms are necessary to best represent appearance and texture in CP-BOLD data. Here we propose and validate a feature learning technique based on multiscale dictionary model that learns to sparsely represent effective patterns under healthy and ischemic conditions.

4527.   9 Dictionary-based Support Vector Machines for Unsupervised Ischemia Detection at Rest with CP-BOLD Cardiac MRI
Marco Bevilacqua1, Anirban Mukhopadhyay1, Ilkay Oksuz1, Cristian Rusu2, Rohan Dharmakumar3,4, and Sotirios A. Tsaftaris1,5
1IMT Institute for Advanced Studies, Lucca, LU, Italy, 2University of Vigo, Vigo, Galicia, Spain, 3Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 4Medicine, University of California, Los Angeles, CA, United States, 5Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, United States

Cardiac Phase-resolved Blood-Oxygen-Level-Dependent (CP-BOLD) MRI has been recently demonstrated to detect an ongoing myocardial ischemia at rest, taking advantage of spatio-temporal patterns in myocardial signal intensities, which are modulated by the presence of disease. However, this approach does require significant post-processing to detect the disease and to this day only a few images of the acquisition are used coupled with fixed thresholds to establish biomarkers. We propose a threshold-free unsupervised approach, based on dictionary learning and one-class support vector machines, which can generate a probabilistic ischemia likelihood map.

4528.   10 An Integer Optimization Technique for Measuring Biventricular Cardiac Strain from Tagged MR Images
Ming Li1,2, Himanshu Gupta3, Steven G. Lloyd3, Louis J. Dell'Italia3, and Thomas S. Denney Jr.1,2
1Auburn University MRI Research Center, Auburn University, Auburn, AL, United States, 2Electrical and Computer Engineering, Auburn University, AL, United States, 3Division of Cardiovascular Disease, University of Alabama at Birmingham, AL, United States

In this abstract we propose an integer optimization based method for unwrapping harmonic phase from tagged cardiac MR images and use this method to compute 3D biventricular cardiac strain through the cardiac cycle. Compared to the traditional quality guided phase unwrapping method, the proposed method was considerably less sensitive to the phase inconsistencies and therefore required less manual intervention. 5 min of automated phase unwrapping and 15 min of manual corrections were required for each study. Biventricular strains from the proposed method were compared to both a feature-based and a phase-based method.

4529.   11 Fully automated strain analysis from SSFP cines of the heart using non-rigid registration techniques
Yun-Jung Jack Tsai1, Yingmin Liu1, Andreas Greiser2, Carmel Hayes2, Helen Lam1, Chris Occleshaw1, Alistair Young1, and Brett Cowan1
1University of Auckland, Auckland MRI Research Group, Auckland, New Zealand, 2Siemens Healthcare, Erlangen, Germany

Cardiac strain quantification is important in the assessment of regional myocardial function, and has many different clinical applications. The current gold standard for non-invasive myocardial strain measurement is cardiac magnetic resonance (CMR) tagging. It is also possible to estimate global and regional strain from standard (non-tagged) steady-state free precession (SSFP) cines using non-rigid registration , thereby removing the need to acquire additional sequences. We report an ‘in-line’ implementation providing numerical and graphical strain measurements without user interaction as part of the standard SSFP acquisition.

4530.   12 Unwrapping-based fat-suppression method for imaging scar using bipolar dual-echo acquisition
Junmin Liu1, Dana C Peters2, and Maria Drangova1,3
1Imaging Research Laboratories, Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontraio, Canada,2Department of Diagnostic Radiology, Yale Medical School, New Haven, Connecticut, United States, 3Department of Medical Biophysics, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada

Dixon techniques to suppress fat signal are sometimes required for assessment of fibrosis/scar with late gadolinium enhancement (LGE). Among Dixon LGE techniques, the bipolar dual-echo technique is intrinsically the fastest, and is thus optimal for high-resolution LGE imaging. However, perfect fat-water separation with bipolar dual-echo acquisition is still very difficult to obtain. We extended a recently published (mono-polar multi-echo) non-iterative phase-unwrapping-based field mapping method (B0-NICE) to this challenging case. The method is tested in three human subjects with left atrial LGE and the results are compared with those obtained using an established region-growing algorithm.

4531.   13 T1-mapping based synthetic phase-sensitive inversion recovery imaging for the accurate quantification of myocardial late gadolinium enhancement
Akos Varga-Szemes1, Rob J van der Geest2, Bruce Spottiswoode3, Giuseppe Muscogiuri1,4, Carlo N De Cecco1,4, Pal Suranyi1, Wolfgang G Rehwald3,5, and U. Joseph Schoepf1
1Medical University of South Carolina, Charleston, SC, United States, 2Leiden University Medical Center, Leiden, Netherlands, 3Siemens Medical Solutions, Chicago, IL, United States, 4University of Rome Sapienza, Rome, Italy, 5Duke Cardiovascular Magnetic Resonance Center, Durham, NC, United States

We evaluated the feasibility of myocardial infarct quantification using synthetic phase-sensitive inversion recovery (PSIR) images. Patients underwent conventional PSIR and prototype modified look-locker IR (MOLLI)-based T1 acquisitions. Synthetic IR images were retrospectively calculated based on the voxel-by-voxel T1 values using an in-house developed application integrated in the Mass Research Software. Late gadolinium enhancement (LGE) measured by conventional and synthetic PSIR techniques showed no statistical difference indicating that LGE quantification using synthetic PSIR images is feasible. With the increasing availability of T1-mapping, the need for conventional PSIR images could be omitted, resulting in a significant reduction in scanner time.

4532.   14 Ungated, Free-breathing Arrhythmia-Insensitive-Rapid (AIR) Cardiac T1 mapping with Motion Corrected Registration
Kyungpyo Hong1,2, Ganesh Adluru1, Edward VR. DiBella1, 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

Cardiac T1 mapping sequences are conducted with breath-holding and ECG-gating to acquire multiple T1-weighted images for calculation of pixel-by-pixel T1map. This approach may fail in patients with arrhythmia and/or poor breath-holding. One approach to address this problem is to perform ungated, free-breathing T1 mapping with motion correction during post processing. We sought to evaluate the performance of ungated, free-breathing arrhythmia-insensitive-rapid (AIR) cardiac T1 mapping with diffeomorphic registration. In 11 patients with atrial fibrillation, compared with ECG-gated breath-holding AIR as the control, ungated, free-breathing AIR with motion correction yielded T1 values that are less than 5% different from control values.

4533.   15 Synthetic LGE Derived Automatically from Cardiac T1 Mapping Using k-means clustering of T1: virtual TI scout approach
Kyungpyo Hong1,2, Edward VR. DiBella1, Akram Shaaban3, Daniel Sommer3, Leif Jensen3, Eugene G. Kholmovski1, Ravi Ranjan4, 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 Radiology, University of Utah, Salt Lake City, Utah, United States, 4Cardiology, Internal Medicine, University of Utah, Salt Lake City, Utah, United States

Late gadolinium-enhanced (LGE) image could be derived from a post-contrast cardiac T1 map using the Bloch equation describing inversion recovery. However, this requires T1 of the normal myocardium to null it. We sought to automatically generate seven synthetic LGE images based on k-means clustering of T1values, without prior knowledge of T1 of the normal myocardium. Data from canines with radio-frequency ablation lesions in the left ventricle show that both standard and synthetic LGE images (derived from cardiac T1 maps) produce 96 and 90% accuracy in lesion detection, respectively.

4534.   16 Motion Correction of Free Breathing Quantitative Myocardial T2 Mapping: Impact on Reproducibility and Spatial Variability
Sébastien Roujol1, Tamer A. Basha1, Sebastian Weingärtner1, Mehmet Akcakaya1, Sophie Berg1, Warren Manning1,2, and Reza Nezafat1
1Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States, 2Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States

Quantitative myocardial T2 mapping sequences generally use a breath-hold ECG-triggered T2-prepared steady-state free precession acquisition. Due to limitations imposed by breath-hold duration, these sequences are typically restricted to the acquisition of four T2-weighted images. Free breathing myocardial T2 mapping sequences remove the time constraint and enable the acquisition of more samples along the T2 decay curve, which may result in improved precision and reproducibility of T2 estimates. We recently developed the ARCTIC motion correction technique which we have evaluated for myocardial T1 mapping. In this study, we sought to evaluate the performance of ARCTIC for motion compensation in free breathing myocardial T2 mapping and to evaluate its impact on in-vivo reproducibility and spatial variability of myocardial T2 estimates.

4535.   17 The influence of geometric and in-flow boundary conditions on patient-specific computational fluid dynamics in a Fontan patient population
Merih Cibis1, Kelly Jarvis2,3, Alex J Barker2, Michael Rose2,4, Cynthia Rigsby2,4, Michael Markl2,3, and Jolanda J Wentzel1
1Biomedical Engineering, Erasmus MC, Rotterdam, Netherlands, 2Radiology, Northwestern University, Chicago, Illinois, United States, 3Biomedical Engineering, Northwestern University, Chicago, Illinois, United States, 4Medical Imaging, Ann& Robert H Lurie Children's Hospital of Chicago, Chicago, Illinois, United States

Previous studies suggested that the hemodynamics of the Fontan connection may play a role in the outcome of Fontan patients. However, the reported hemodynamic parameters in the literature, such as flows and power losses inside Fontan circuit show large discrepancies and the segmentation of the Fontan circuit might be one of the causes of the discrepancy. In this study, our aim was to investigate the influence of segmentation on the estimated geometrical and hemodynamic parameters. We showed that lumen segmentation on different image types might lead to significant differences in the estimated lumen diameters, flows and subsequent power losses.

4536.   18 In-vivo Systolic Pressure Gradients across the Aortic Root in Patients with a Physiologically Shaped Sinus Prosthesis and Healthy Volunteers Analyzed by 4D Flow MRI
Thekla Oechtering1, Carl Frederik Hons1, Julian Haegele1, Peter Hunold1, Michael Scharfschwerdt2, Anja Hennemuth3, Markus Huellebrand3, Hans-Hinrich Sievers2, Jörg Barkhausen1, and Alex Frydrychowicz1
1Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Lübeck, Germany, 2Department of Cardiac and Cardiothoracic Vascular Surgery, University Hospital Schleswig-Holstein, Lübeck, Germany, 3Fraunhofer MEVIS, Bremen, Germany

The physiologically shaped sinus prosthesis (Uni-Graft® W SINUS, Braun) should preserve near-normal pressure gradients across the aortic root. By means of 4D Flow MRI we analyzed transvalvular pressure gradients and their time course in 6 patients with sinus prosthesis in comparison to 12 healthy volunteers and pressure gradients derived from follow-up echocardiography. Peak pressure gradients did not differ significantly between patients and volunteers or between MRI and echocardiography in patients. Temporal evolution of pressure gradients was consistent with normal pressure gradients. The Venturi effect could be demonstrated across the aortic valve with a pressure drop in the bulb in peak systole.

4537.   19 3D cine Atherosclerotic Plaque Images using 3D Stack of Stars Trajectory Acquisition and ciné Reconstruction Method using Retrospective Ordering and Compressed Sensing (ciné-ROCS)
Seong-Eun Kim1, John A. Roberts1, J. Scott Mcnally1, Bradley D. Bolster, Jr.2, Gerald S. Treiman3,4, and Dennis L. Parker1
1UCAIR, Department of Radiology, University of Utah, Salt Lake City, Utah, United States, 2Siemens Healthcare, Salt Lake City, Utah, United States,3Department of Surgery, University of Utah, Salt Lake City, Utah, United States, 4Department of Veterans Affairs, VASLCHCS, Salt Lake City, Utah, United States

Cardiac pulsations cause blurring of wall morphology. Gated acquisition increases scan time and results in image degradation due to non-constant TR. We have developed a cardiac or respiratory ciné reconstruction method using retrospective ordering and compressed sensing (ciné-ROCS) to minimize, characterize, and eliminate the artifacts. A Radial based k-space trajectory may offer reduced motion sensitivity, reduced artifacts and more robust ciné-ROCS reconstructions due to its inherent oversampling of central k-space. The goal in this study was to incorporate ciné-ROCS into 3D Stack of Stars sequence to demonstrate improvements for reliable plaque imaging and individual plaque component identification.

4538.   20 Whole-brain intracranial arterial wall imaging at 3 Tesla: 3D TSE with CSF attenuation and enhanced T1 weighting
Zhaoyang Fan1, Qi Yang1,2, and Debiao Li1
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States, 2Radiology, Xuanwu Hospital, Beijing, China

High resolution dark-blood MRI has been used to evaluate the intracranial arterial wall and provide findings indicative of wall thickening, intraplaque hemorrhage, or inflammation. T1-weighted 3D variable-flip-angle TSE has gain popularity in this research area but involves limitations including obscured outer wall boundary by CSF and limited spatial coverage. This work developed a 3D TSE technique that provides CSF attenuated 0.5-mm isotropic resolution whole-brain wall imaging within a reasonable scan time. With enhanced T1 weighting, the technique would be useful in the assessment of both plaque burden and high-T1-signal wall abnormalities in the incracranial artery wall.

4539.   21 Volumetric Aortic Vessel Wall MRI using Improved Flow-Independent T2-Prepared Phase Sensitive Inversion Recovery at 3T
M.G.M. van de Steeg1,2, M. Henningsson2, A. Noorani2, K. Nicolay1, and R. Botnar2
1Division of Molecular Bioengineering and Molecular Imaging, Eindhoven University of Technology, Eindhoven, Netherlands, 2Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom

T2prepared Phase Sensitive Inversion Recovery (T2prep-PSIR) shows an enhanced distinction between vessel wall and surrounding tissue in black-blood MRI. This is especially useful in patients with aortic dissection. However, significant flow artifacts may occur when the T2prep is performed in a cardiac phase with high blood flow, even when performed in early systole. We developed an adapted T2prep-PSIR, in which a T2prep is performed during slow blood flow in end-diastole and compared it with conventional T2prep-PSIR. Assessment was based on visual score and compared to blood flow curves. The adapted sequence shows an improved visualization of the aortic vessel wall.

4540.   22 Comparison between carotid wall T1,T2 quantifications with and without 3D iMSDE reference scan
Shan Gao1, Bram F. Coolen2, Rob J. van der Geest1, Dirk H.J. Poot3,4, and Aart J. Nederveen2
1Division of Image Processing, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands, 2Radiology, Academic Medical Center, Amsterdam, Netherlands, 3Biomedical Imaging Group Rotterdam, Erasmus MC Rotterdam, Rotterdam, Netherlands, 4Imaging Science and Technology, Delft University of Technology, Delft, Netherlands

Carotid artery T1 and T2 mapping requires careful registration to deal with motion between the individual quantitative scans. Furthermore T1 and T2 estimates rely on accurate vessel wall segmentation. In this study we investigated whether incorporating an additional 3D black-blood reference scan in the registration and segmentation pipeline improves carotid artery T1 and T2 quantification.

4541.   23 Lumen expansion at five locations along the venous system of murine models
Olivia Palmer1, Amos Cao2, Ulrich Scheven2, Jose A Diaz3, and Joan M Greve2
1Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States, 2Biomedical Engineering, University of Michigan, MI, United States, 3Surgery, Section of Vascular Surgery, Conrad Jobst Vascular Research Lab, University of Michigan, MI, United States

Cardiovascular disease is the number one killer in the United States and worldwide. The venous system is understudied, a discrepancy which must be corrected as the US population with deep vein thrombosis is projected to double by 2050. Flow and pressure are known to differ in the venous system compared to the arterial system. Wall shear stress and wall motion are not well-defined. This work focuses on the last, comparing lumen expansion along the venous system of murine models. Lumen expansion was independent of gender and maximum values were less than half the expansion typically seen in the arterial system.

4542.   24 The effect of Ivabradine on plaque size, biomechanics, and microvasculature in atherosclerotic rabbits measured using MR and Ultrasound Imaging
Raf H.M. van Hoof1,2, Evelien Hermeling1,2, Julie Salzmann3, Judith C. Sluimer2,4, Sylvia Heeneman2,4, Arnold P.G. Hoeks2,5, Harry A.J. Struijker-Boudier2,6, Jérôme Roussel3, Joachim E. Wildberger1,2, and M. Eline Kooi1,2
1Radiology, Maastricht University Medical Center, Maastricht, Netherlands, 2Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, Netherlands, 3Institut de Recherches Internationales Servier, Suresnes, France, 4Pathology, Maastricht University Medical Center, Maastricht, Netherlands, 5Biomedical Engineering, Maastricht University Medical Center, Maastricht, Netherlands, 6Pharmacology, Maastricht University Medical Center, Maastricht, Netherlands

The effect of Ivabradine, a heart rate lowering drug, on the formation of atherosclerosis in cholesterol-fed rabbits was investigated. Plaque size and microvasculature was measured using (Dynamic Contrast-Enhanced) MRI and plaque biomechanics using ultrasound imaging. Results showed no difference in plaque size and beat-to-beat biomechanics, but a decrease in heart rate and plaque microvasculature determined using semi-quantitative (Area-Under-the-Curve) and quantitative (Ktrans) parameters. Thus, use of Ivabradine led to decreased plaque microvasculature, which is thought to be an important determinant of reduced plaque vulnerability.

Thursday 4 June 2015
Exhibition Hall 11:30 - 12:30

  Computer #  
4543.   25 Intracranial k-t Accelerated Dual-Venc 4D flow MRI
Susanne Schnell1, Can Wu1,2, Ian G Murphy1, Julio Garcia1, and Michael Markl1,2
1Radiology, Northwestern University, Chicago, Illinois, United States, 2Biomedical Engineering, Northwestern University, Evanston, Illinois, United States

A newly developed dual-venc 4D flow MRI sequence was applied in healthy volunteers. The k-t GRAPPA accelerated dual-venc 4D flow MRI sequence was developed using a shared reference scan for both low- and high-venc acquisition within a single scan. The resulting dual-venc data was combined using the low- and high-venc data, whereby the high-venc scan was solely used for anti-aliasing purposes. The findings of this feasibility study showed that dual-venc 4D flow MRI can provide improved visualization and quantification of venous and arterial hemodynamics across a wide range of the velocity spectrum. Velocity noise was reduced compared to single-venc implementations.

4544.   26 Accelerating Flow Encoded MRI by Exploiting Vector Field Divergence Regularization
Claudio Santelli1,2, Michael Loecher3, Julia Busch2, Oliver Wieben3,4, Tobias Schaeffter1, and Sebastian Kozerke1,2
1Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 2Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 3Department of Medical Physics, University of Wisconsin-Madison, Wisconsin, United States, 4Department of Radiology, University of Wisconsin-Madison, Wisconsin, United States

Iterative image reconstruction in which magnitude and phase are regularized separately was implemented to improve velocity vector field reconstruction from undersampled 3D flow MRI data by penalizing divergence of the measured flow field. Velocity data was regularized to reduce divergence, using either a finite difference (FD) or divergence-free Wavelets (DFW) method. They were tested on simulated and in-vivo data and compared to standard Compressed Sensing (CS) reconstruction. Phase regularization led to reduced directional error and divergence, increased streamline length and improved vector field visualization.

4545.   27 New Method for Efficient, Volumetric Quantification of Aortic Hemodynamics
Michael J Rose1, Kelly Jarvis2,3, Varun Chowdhary2, Alex J Barker2, Bradley D Allen2, Joshua D Robinson4,5, Michael Markl2,3, Cynthia K Rigsby1,2, and Susanne Schnell2
1Medical Imaging, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, United States, 2Radiology, Northwestern University, Chicago, IL, United States, 3Biomedical Engineering, Northwestern University, Chicago, IL, United States, 4Pediatrics, Northwestern University, Chicago, IL, United States, 5Pediatric Cardiology, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, United States

Currently, standard methods for measuring systolic peak velocity, an important clinical measure of aortic valve stenosis severity, are Doppler echocardiography and 2D phase contrast MRI. Both these methods, due to single-direction velocity encoding and reliance on manually placed 2D analysis planes, can underestimate true peak velocity in the case of complex flow jets as often seen in patients with aortic valve disease. 4D flow MRI, having three-directional velocity encoding, can better accommodate complex blood flow. In this study, we employ a new approach to measuring peak velocity using systolic velocity maximum intensity projections based on aortic 4D flow MRI data.

4546.   28 Dual-Velocity Encoding Phase-Contrast MRI: extending the dynamic range and lowering the velocity to noise ratio
Susanne Schnell1, Julio Garcia1, Can Wu1,2, and Michael Markl1,2
1Radiology, Northwestern University, Chicago, Illinois, United States, 2Biomedical Engineering, Northwestern University, Evanston, Illinois, United States

A new Cartesian dual-venc phase-contrast MRI sequence was developed applying one reference scan and 6 velocity encoding gradients in three orthogonal directions using two different velocity encoding strengths. All 7 encodings are played within one cardiac phase and the shortest possible TR and TE. The gradient’s Maxwell terms are calculated and corrected during reconstruction. Rotation phantom experiments were performed to evaluate the combined anti-aliased high dynamic range velocity data with low velocity to noise ratio.

4547.   
29 Assessing Caval Flow Distribution in Patients with Fontan Circulation using 4D Flow MRI and Probabilistic Flow Connectivity Mapping
Kelly Jarvis1,2, Susanne Schnell1, Alex J Barker1, James Carr1, Joshua D Robinson3,4, Cynthia K Rigsby1,4, 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, 4Medical Imaging and Cardiology, Ann & Robert H Lurie Children’s Hospital of Chicago, IL, United States

Non-uniform distribution of caval blood flow to the left and right lung is suspected to cause complications in patients with Fontan circulation. Caval flow distribution can be comprehensively assessed using 4D flow MRI. However, 3D flow visualization of 4D flow data by traditional single pathline methods does not take into account the effects of velocity noise that may propagate over time-steps in the cardiac cycle. The aim of this study was to systematically analyze 3D probabilistic flow connectivity mapping of 4D flow data for taking into account the influence of noise in flow distribution quantification for patients with Fontan circulation.

4548.   30 Impact of View Ordering and Soft-Gating on Morphologic Assessment of Congenital Heart Disease with 4D Flow
Joseph Y Cheng1,2, Kate Hanneman2, Tao Zhang1,2, Marcus T Alley2, Peng Lai3, Jonathan I Tamir4, Martin Uecker4, Michael Lustig4, John M Pauly1, and Shreyas S Vasanawala2
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Radiology, Stanford University, Stanford, CA, United States, 3Global MR Applications & Workflow, GE Healthcare, Menlo Park, CA, United States, 4Electrical Engineering and Computer Sciences, University of California, Berkeley, CA, United States

Volumetric time-resolved phase contrast MRI (4D flow) permits evaluation of congenital heart disease (CHD). The ease of prescribing the scan and the ability to quantify function and flow make the technique compelling for CHD. However, a comprehensive CHD exam must also assess anatomy. Therefore, we evaluated the performance of a soft-gated compressed-sensing 4D flow technique by assessing anatomy. With IRB approval and informed consent, 23 consecutive patients were scanned using 4D flow with ferumoxytol enhancement. Images from the developed view-ordering scheme with soft-gating were determined to have improved morphologic diagnostic quality with no loss in flow quantification accuracy.

4549.   31 Radial displacement errors and correction efficiency for streamline visualization in 4D-Flow MRI
Michael Loecher1, Kevin M Johnson1, Patrick Turski2, and Oliver Wieben1,2
1Medical Physics, University of Wisconsin Madison, Madison, Wisconsin, United States, 2Radiology, University of Wisconsin Madison, Madison, Wisconsin, United States

Visualizing 4D flow MRI data with streamlines has become an important tool for assessing vascular hemodynamic. However streamlines can be severely degraded due to displacement artifacts from radial acceleration and misrepresent the actual flow field. This work tests the effectiveness of various correction techniques in reducing the effects of displacement artifacts. Results show significant improvements for iterative streamline based methods, as well as combing this with divergence-free algorithms.

4550.   32 Clinical Evaluation and Optimization of Highly Accelerated 2D and 4D Phase Contrast Flow Imaging Applications using Sparse Sampling and Iterative Reconstruction
Andreas Greiser1, Christoph Forman1, Jens Wetzel2, Christoph Tillmanns3, Aurelien F. Stalder1, Michaela Schmidt1, Michael Zenge4, and Edgar Mueller1
1Siemens AG, Healthcare, Imaging & Therapy Systems, Magnetic Resonance, Erlangen, Bavaria, Germany, 2Department of Computer Science, Friedrich-Alexander-Universität Erlangen-Nuernberg, Pattern Recognition Lab, Erlangen, Bavaria, Germany, 3Diagnostikum Berlin, Berlin, Germany, 4Siemens Healthcare, NY, United States

We validated the method of an optimized regularization in 2D k-t-sparse cine phase contrast in volunteers and patients and 4D PCI lasting 6 minutes. For 2D, average absolute difference between reference and accelerated was 3.10 ml for net forward volume (NFV) and 8.58 ml for vmax, systematic difference was 1.19%/-0.65% for vmax/NFV. In 4D average relative difference was -3.75%/-3.32% for vmax/NFV, average absolute difference was 7.91% and 5.23% for vmax/NFV. Short-breathhold single-slice and fast 4D flow acquisitions are feasible without apparent drawbacks. The inline reconstruction on a standard clinical scanner allows the use of iterative reconstruction techniques in clinical practice.

4551.   33 Comparison of MRI and CFD based wall shear stress and their relationship with wall thickening in human carotid arteries
Merih Cibis1, Wouter V Potters2, Mariana Selwaness3, Frank J Gijsen1, Andres M Arias Lorza4, Aad van der Lugt3, Aart J Nederveen2, and Jolanda J Wentzel1
1Biomedical Engineering, Erasmus MC, Rotterdam, Netherlands, 2Radiology, AMC, Amsterdam, Netherlands, 3Epidemiology, Erasmus MC, Rotterdam, Netherlands, 4Radiology and Medical Informatics, Erasmus MC, Rotterdam, Netherlands

Wall shear stress inside vessels is associated with atherosclerosis and calculated generally by computational fluid dynamics (CFD) and more recently by flow MRI data. It is of vital importance to know if CFD and MRI based WSS associate similarly with the early markers of atherosclerosis, such as wall thickening. We therefore compared CFD and MRI based WSS in elderly healthy population and also their association with wall thickness. We showed that both CFD and MRI based WSS results show an inverse relationship with WT in internal carotid artery but WSS in common carotid artery must be interpreted more carefully.

4552.   34 USPIO enhanced 3D-cine Phase Contrast of the whole cardiovascular system in small animals at 7T with an Ultrashort Echo Time Sequence - permission withheld
Aurélien Julien Trotier1, Charles Castets1, William Lefrancois1, Jean-Michel Franconi1, Eric Thiaudière1, and Sylvain Miraux1
1RMSB-UMR5536, CNRS - Université de Bordeaux, Bordeaux, Aquitaine, France
 
Time-Resolved Phase Contrast sequences is mostly performed in 2D or in thin 3D volumes with cartesian sequences. This strategy is not applicable on the whole mouse cardiovascular system due to the saturation of the spin into this volume. To overcome this problem we proposed to use a new 3D time-resolved Phase Contrast UTE sequence in combinaison with an injection of Ultra Small Particles of Iron Oxide to obtain a positive signal in blood. Method was optimized (Phase error correction, TE < 0.6 ms) to generate 4D low images at 7T with a spatial resolution of 156 µm. Flow measurements can be performed in numerous cardiac an pulmonary vessels of mice models.

4553.   35 Inter breath-hold reproducibility of high temporal resolution spiral phase velocity mapping of coronary artery blood flow and in vivo validation against Doppler flow wire
Jennifer Keegan1, Claire Raphael1, Kim Parker2, Robin Simpson3, Ranil de Silva1, Carlo Di Mario1, Julian Collinson4, Rod Stables5, Stephen Strain1, Sanjay Prasad1, and David Firmin1,2
1Royal Brompton Hospital, London, United Kingdom, 2Imperial College, London, United Kingdom, 3Radiological Physics, Freiburg, Germany, 4Chelsea and Westminster Hospital, United Kingdom, 5Liverpool Heart and Chest Hospital, 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 assess the reproducibility of breath-hold high temporal resolution (19ms) spiral phase velocity mapping of coronary flow velocity and validate it against invasive ‘gold-standard’ Doppler flow wire measurements. As expected, MR velocities are lower than Doppler velocities but the temporal flow patterns are highly similar (R2 = .60 - .97). Inter breath-hold reproducibility of MR velocities is excellent. We conclude that spiral phase velocity mapping can assess temporal patterns of coronary flow velocity non-invasively.

4554.   36 Impact of Aortic Valve Replacement on Turbulent Flow Characteristics
Christian Binter1, Alexander Gotschy1,2, Robert Manka1,3, Simon H. Sündermann4, and Sebastian Kozerke1,5
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Dept. of Internal Medicine, University Hospital Zurich, Switzerland,3Dept. of Cardiology, University Hospital Zurich, Switzerland, 4Division of Cardiovascular Surgery, University Hospital Zurich, Switzerland, 5Imaging Sciences and Biomedical Engineering, King's College London, United Kingdom

Phase-Contrast MRI allows for time-resolved quantification of velocities in the aortic arch and the assessment of the energy stored in turbulent flow. This information potentially offers a more direct assessment of the severity of aortic stenosis than parameters derived from Doppler echocardiography. The present study compares turbulence levels in patients before and after aortic valve replacement as well as age-matched controls and relates the findings to disease severity markers as determined by echocardiography. Significant differences between groups were found for both Turbulent Kinetic Energy and Mean Pressure Gradient.

4555.   37 Preliminary fetal hemodynamic patterns in late gestation fetuses with common forms of cyanotic congenital heart disease by phase contrast MRI and T2 mapping
Prashob Porayette1, Christopher Macgowan2, Sujana Madathil1, Edgar Jaeggi1, Lars Grosse-Wortmann1, Shi-Joon Yoo3, John Kingdom4, Greg Ryan5, Steven Miller6, and Mike Seed1
1Pediatric Cardiology, The Hospital for Sick Children, Toronto, ON, Canada, 2Physiology & Experimental Medicine, The Hospital for Sick Children, Toronto, ON, Canada, 3Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, Canada, 4Obstetrics & Gynaecology, Mount Sinai Hospital, Toronto, ON, Canada, 5Maternal-Fetal Medicine, Mount Sinai Hospital, Toronto, ON, Canada, 6Neurology, The Hospital for Sick Children, Toronto, ON, Canada

We have recently published the reference ranges for blood flow in normal human fetal circulation. In this study, we demonstrated the flow as well as the oxygen saturation measurements using novel MRI techniques in major vessels of fetuses with common cyanotic congenital heart disease.

4556.   38 Self-Gated Tissue Phase Mapping using Golden Angle Radial Sparse SENSE
Jan Paul1, Stefan Wundrak1, Peter Bernhardt1, Wolfgang Rottbauer1, Heiko Neumann2, and Volker Rasche1
1Internal Medicine II, University Hospital Ulm, Ulm, Germany, 2Institute of Neural Information Processing, University of Ulm, Ulm, Germany

Tissue Phase Mapping (TPM) allows analysis of global and regional LV motion and calculation of motion quantification parameters. Due to the long scan time of high-resolution or volumetric TPM acquisitions, respiratory motion has to be considered. In this study, image-based self-gating (SG) is compared to conventional pencil beam (RNAV) gating for TPM acquisitions. Additionally, the influence of the regularization strength lower case Greek lambda in the radial SPARSE SENSE reconstruction on the velocities is investigated.

4557.   39 Spatio-temporal sacrifices for wall shear stress and oscillatory shear stress calculations
Wouter V Potters1, Merih Cibis2, Frank JH Gijsen2, Henk A Marquering1,3, Ed vanBavel3, Jolanda J Wentzel2, and Aart J Nederveen1
1Radiology, Academic Medical Center, Amsterdam, Netherlands, 2Biomedical Engineering, Erasmus Medical Center, Rotterdam, Netherlands, 3Biomedical Engineering & Physics, Academic Medical Center, Amsterdam, Netherlands

Wall shear stress (WSS) and oscillatory shear stress (OSI) depend on the spatial and temporal resolution. We assessed these spatio-temporal dependencies using an in vitro carotid bifurcation phantom based on the geometry and the flow profile from a healthy volunteer. 36 2D PC MRI measurements with varying spatio-temporal resolution were analyzed using fully-automatic segmentation and a WSS calculation algorithm to retrieve WSS and OSI values. The results show that both OSI and WSS magnitude are heavily influenced by spatio-temporal resolution. OSI tends to be more effected by temporal resolution, whereas WSS magnitude tends to be more effected by spatial resolution.

4558.   40 4D vs. 2D flow MRI in 109 patients with dilated ascending aorta: Improved Assessment of Peak Systolic Velocity
Martin Fasshauer1,2, Alexander L. Powell3, Alex J. Barker3, Susanne Schnell3, Joachim Lotz1,2, and Michael Markl3,4
1Institute for Diagnostic And Interventional Radiology, University Medical Center Goettingen, Goettingen, Lower saxony, Germany, 2German Center for Cardiovascular Research, DZHK, partner site Goettingen, Germany, 3Department of Radiology, Nortwestern University, Chicago, IL, United States,4Department of Biomedical Engineering, Northwestern University, Chicago, IL, United States

Thoracic aortic aneurysms are a life threatening disease due to the common absence of symptoms in most patients. Our study applies 4D flow MRI for assessment of complex flow patterns and comparison of 2D peak systolic velocity in 109 patients with dilated ascending aorta. Our study shows that 4D PC-MRI has the potential to yield more accurate peak velocities in complex flow environments.

4559.   41 Analysis of Aortic Pulse Wave Velocities using Real-time PC MRI
Arun Antony Joseph1, Martin Fasshauer2, Klaus-Dietmar Merboldt3, and Jens Frahm3
1Biomedizinsche NMR Forschungs GmbH am Max Planck Institut fuer biophysikalische Chemie, Goettingen, Niedersachsen, Germany, 2Abteilung Diagnostische Radiologie, Universitätsmedizin Goettingen, Niedersachsen, Germany, 3Biomedizinsche NMR Forschungs GmbH am Max Planck Institut fuer biophysikalische Chemie, Niedersachsen, Germany

Real-time PC imaging with highly undersampled radial FLASH and regularized nonlinear inversion reconstruction was used for the analysis of pulse wave velocity. Access to flow parameters from multiple cardiac cycles by real-time PC MRI provides accurate analysis of pulse wave velocity at short acquisition times. Pulse wave velocity values obtained from real-time PC MRI were further compared with Cine PC MRI.

4560.   42 MR Phase-Contrast Imaging with Automatic Inline Flow Quantification and Visualization - permission withheld
Mehmet Akif Gulsun1, Arne Littmann2, Timothy Slesnick3, Ning Jin4, Andreas Greiser2, Marie-Pierre Jolly1, Gary McNeal4, and Aurelien F Stalder2
1Imaging and Computer Vision, Siemens Corporate Technology, Princeton, NJ, United States, 2Siemens Healthcare, Erlangen, Germany, 3Emory University School of Medicine, Children's Healthcare of Atlanta, GA, United States, 4Siemens Healthcare, IL, United States

This work presents an automatic inline flow processing method for analysis of 2D PC MRI data. Flow images were automatically processed at the scanner for background phase correction, dynamic vessel segmentation, flow quantification and advanced visualization. The proposed method substantially reduces the complexity and time required for flow analysis and provides an effective way to review the flow analysis results just after the acquisition so as to repeat the acquisition while the patient is still in the scanner in case of inconsistency. Inline flow processing could contribute to making application of 2D PC in the clinical routine easier, faster and more accurate.

4561.   43 High-Acquisition-Efficiency Cardiac 4D Flow MRI for High-SNR Motion-Robust Imaging with Contrast Agent During Delayed Enhancement Wait Time
Peng Lai1, Ann Shimakawa1, Joseph Y Cheng2, Marcus T Alley2, Shreyas S Vasanawala2, and Anja CS Brau3
1Global MR Applications & Workflow, GE Healthcare, Menlo Park, CA, United States, 2Radiology, Stanford University, CA, United States, 3Global MR Applications & Workflow, GE Healthcare, Munich, Germany

Cardiac 4D flow with conventional parallel imaging and respiratory gating requires long scan time, substantially prolonging cardiac exam time. This work developed a new free-breathing 4D flow method with high scan efficiency and under 7min scan time. Our results show that the proposed approach can effectively suppress respiratory motion and achieve high acceleration and potentially enables pre-LGE 4D flow imaging with high blood signal.

4562.   44 Assessment of Flow Vorticity in the Right Heart of Patients with Repaired Tetralogy of Fallot
Julio Garcia1, Daniel Hirtler2, Alex J Barker1, and Julia Geiger2,3
1Radiology, Northwestern University, Chicago, Illinois, United States, 2Congenital Heart Defects and Pediatric Cardiology, University Hospital Freiburg, Freiburg, Germany, 3Radiology, University Childrens’ Hospital Zurich, Zurich, Switzerland

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart defect. TOF patients usually undergo corrective surgery early in life. This evaluated flow disturbances due to vortex formation in the right atrium (RA) and right ventricle (RV) hemodynamics of TOF patients after repair (rTOF) using qualitative and quantitative vorticity.

4563.   45 Coil Array Compression for Tissue Phase Mapping
Jan Paul1, Stefan Wundrak1, Heiko Neumann2, and Volker Rasche1
1Internal Medicine II, University Hospital Ulm, Ulm, Germany, 2Institute of Neural Information Processing, University of Ulm, Ulm, Germany

Coil arrays with many elements are applied to enable higher acceleration factors in parallel imaging. However, the increased amount of data slows down the reconstruction process. Coil array compression has been introduced to combine the data into fewer ‘virtual coils’, thus reducing the amount of data while preserving most of the information. In this contribution, the influence of coil array compression on reconstructed velocities for Tissue Phase Mapping (TPM) is investigated.

4564.   46 4D Flow MRI to monitor mean Pulmonary Arterial Pressure in Patients with Chronic Thromboembolic Pulmonary Hypertension treated by Percutaneous Transluminal Pulmonary Angioplasty
Hideki Ota1, Koichiro Sugimura2, Haruka Sato2, Kotaro Nochioka2, Shunsuke Tatebe2, Saori Yamamoto2, Masanobu Miura2, Kimio Satoh2, Yuta Urushibata3, Yoshiaki Komori3, Aurelien F. Stalder4, Andreas Greiser4, Hiroaki Shimokawa2, and Kei Takase1
1Diagnostic Radiology, Tohoku University Hospital, Sendai, Miyagi, Japan, 2Cardiology, Tohoku University Hospital, Sendai, Miyagi, Japan, 3Siemens Japan K.K, Tokyo, Japan, 4Siemens Healthcare, Erlangen, Germany

In chronic thromboembolic pulmonary hypertension (CTEPH), percutaneous transluminal pulmonary angioplasty improves patientsf prognosis. There is a need to monitor mean pulmonary arterial pressure (mPAP) in long-term follow-up of patients who undergo angioplasty. Parameters of 4D flow and cardiac cine MR imaging were evaluated for a potential estimator of mPAP in 16 patients with CTEPH. Vortex flow in the pulmonary trunk was observed on 4D flow MR images in all patients. Backward flow area ratio in the end-systolic phase in the pulmonary trunk was the strongest estimator for both baseline mPAP before angioplasty and change of mPAP after angioplasty.

4565.   47 4D flow MRI assessment of Cerebrospinal Venous blood flow in Multiple Sclerosis Patients and Age/Sex-Matched Controls
Eric Mathew Schrauben1, Kevin M Johnson1, Aaron Field2, and Oliver Wieben1,2
1Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin, United States, 2Radiology, University of Wisconsin - Madison, Madison, Wisconsin, United States

Blood flow measurements using 4D flow MRI are compared between MS patients and healthy controls in cerebrospinal veins. No significant difference in flow pattern between the groups was found.

4566.   48 Systolic pressure gradients derived from 4D flow in a physiological healthy and aortic coarctation phantom versus cardiac catheterization
Jesús Urbina1,2, Julio Sotelo2,3, Cristian Montalba2, Cristián Tejos2,3, Pablo Irarrázaval2,3, Marcelo Andía2,4, Israel Valverde5,6, and Sergio Uribe2,4
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, 4Radiology Department, Pontificia Universidad Católica de Chile, Santiago, Chile, 5Pediatric Cardiology Unit, Hospital Virgen del Rocio, Seville, Spain, 6Institute of Biomedicine of Seville, Universidad de Sevilla, Seville, Spain

Peak to peak pressure gradient through the aortic coarctation is the clinical standard to determine the severity of this disease and to refer patients to surgery repair. Pressure gradient can be measured with echocardiography and catheterization. During the last years, 4D flow has emerged as a MRI technique capable to measure hemodynamic parameters. The purpose of this work is to evaluate the accuracy of pressure gradients derived from 4D flow compared with catheterization in controlled experiments using a physiological healthy and aortic coarctation phantoms at rest and stress conditions.

Thursday 4 June 2015
Exhibition Hall 11:30 - 12:30

  Computer #  
4567.   49 Simultaneous Multi-Slice Dark Blood Cardiac Imaging using Multiband Double-Inversion Recovery TSE - video not available
Dingxin Wang1,2, Edward Auerbach2, Gary McNeal3, Peter Kollasch1, Uma Valeti4, Vibhas Deshpande5, Kamil Ugurbil2, and Greg Metzger2
1Siemens Healthcare, Minneapolis, Minnesota, United States, 2CMRR, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, United States, 3Siemens Healthcare, Dallas, Texas, United States, 4Departments of Medicine and Radiology, University of Minnesota, Minneapolis, Minnesota, United States, 5Siemens Healthcare, Austin, Texas, United States

Our study demonstrates, for the first time, the feasibility of simultaneous multi-slice cardiac dark blood imaging using double-inversion recovery multiband slice accelerated TSE. Multiband slice acceleration improves the acquisition efficiency of TSE dark blood imaging beyond what is possible with standard in-plane parallel imaging acceleration thus allowing more slice coverage per breath hold and reducing the number of breath holds required to obtain whole heart coverage.

4568.   50 Free-Breathing Diffusion Tensor MRI of the Entire Human Heart In Vivo Using Simultaneous Multislice Excitation and Spatiotemporal Registration
Choukri Mekkaoui1, Timothy G Reese2, Stephen F Cauley2, Kawin Setsompop2, Himanshu Bhat3, William J Kostis2, Marcel P Jackowski4, and David E Sosnovik2
1Harvard Medical School - Massachussetts General Hospital, Boston, MA, United States, 2Harvard Medical School-Massachusetts General Hospital, Boston, MA, United States, 3Siemens, Boston, MA, United States, 4University of São Paulo, São Paulo, Brazil

Successful clinical translation of cardiac Diffusion Tensor Imaging (DTI) will require efficient free-breathing techniques to be developed. We combined simultaneous multislice (SMS) excitation and a diaphragmatic navigator (NAV) to perform free-breathing DTI of the entire human heart in vivo in less than 25 minutes. DTI of the heart was performed using a NAV-based blipped-CAIPI stimulated echo sequence with rate 3 SMS excitation and spatiotemporal registration (STR), with minimal loss of image quality. The elimination of breath-holds in favor of a free-breathing NAV approach makes cardiac DTI accessible to patients with a broad range of cardiovascular conditions.

4569.   51 Respiratory Resolved Cardiac Cine Imaging using Self-Gated Golden Angle Radial Acquisition
Karen Holst1, Martin Ugander1, and Andreas Sigfridsson1
1Department of Clinical Physiology, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden

Respiratory variation in ventricular shape may provide clinically important information, which can be measured using respiratory resolved imaging. Golden angle radial data were acquired during free breathing, and cardiac and respiratory self-gating signals were extracted. All radial spokes were sorted into combinations of respiratory and cardiac phases and left ventricular (LV) area was measured from end-diastolic images over 10 respiratory phases. Self-gating signals and LV area measurements showed good correspondence with similar images from real time cine. Respiratory induced changes in LV area could be detected and the golden angle method provided higher image quality and flexibility.

4570.   52 Cardiac Magnetic Resonance Imaging with Doppler Ultrasound as alternative trigger method at 3T
Fabian Kording1, Bjoern Schoennagel1, Friedrich Ueberle2, Gunnar Lund1, Gerhard Adam1, and Jin Yamamura1
1Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany, 2Faculty of Life Sciences, University of Aplied Sciences, Hamburg, Germany

Doppler Ultrasound and its potential to provide more details for cardiac MRI triggering was evaluated at 3T in comparison to VCG and pulse oximetry. Trigger signals of each method were acquired simultaneously for short axis cine and phase contrast sequences. Trigger sensitivity and RR interval length were compared between each method and showed high accuracy. Motion blurring was assess by endocardial border sharpness and showed a significant decrease for DUS triggered images during diastole. The appearance of DUS trigger signals correlated strong with quiescent heart phases which was successfully used for coronary MRA

4571.   53 4D flow MRI of the Great Vessels during Respiration Plateaus
Eric Mathew Schrauben1, Christopher J François2, Oliver Wieben1,2, and Alejandro Roldán-Alzate2
1Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin, United States, 2Radiology, University of Wisconsin - Madison, Wisconsin, United States

4D flow MRI, gated to both respiratory and cardiac cycles, is used to assess respiratory plateau induced waveform changes in Great Vessels of healthy controls.

4572.   54 Multi-channel double-tuned TX/RX RF coil using loop elements for 23Na and loopole elements for 1H cardiac MR imaging at 7.0 Tesla
Helmar Waiczies1, Jan Rieger1, Armin M. Nagel2, Andreas Graessl3, Lukas Winter3, and Thoralf Niendorf3
1MRI.Tools GmbH, Berlin, Germany, 2Division of Medical Physics in Radiology, Cancer Research Center (DKFZ), Heidelberg, Germany, 3Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine, Berlin, Germany

Sodium MRI (23Na-MRI) is an emerging approach for gaining metabolic insights in Cardiovascular MRI. It has been shown to be suitable for the detection and assessment of acute and chronic heart disease due to increased sodium concentration after myocardial infarction. Therefore it is conceptually appealing to use the sensitivity gain intrinsic to ultrahigh fields for cardiac 23Na-MRI. This work proposes a multi-channel transmit and receive (TX/RX) radiofrequency (RF) coil that supports four TX/RX channels (loop elements) for 23Na and two 1H TX/RX channels (loopole elements) for cardiac imaging at 7.0T

4573.   55 7D DSA : A Dual Modality Combination of 4D DSA and 4D Flow MRI
CHARLES ANTHONY MISTRETTA1, CHARLES STROTHER2, and OLIVER WIEBEN1
1MEDICAL PHYSICS AND RADIOLOGY, U OF WISCONSIN-MADISON, MADISON, WI, United States, 2RADIOLOGY, U OF WISCONSIN-MADISON, MADISON, WI, United States

We present a new imaging modality that embeds velocity or velocity-derived information from 4D flow MRI into time resolved 4D DSA volumes. This is done using a 2nd order constrained reconstruction in which the 4D DSA frames are formed using a 3D DSA constraint and the time-dependent angular projections acquired during iodine inflow. Then, a time averaged velocity map provided by PC-VIPR is used as a constraining image that is modulated by the 4D DSA temporal volumes. SNR and spatial resolution are provided by the 4D DSA data while color-coded velocity information is provided by the MR data.

4574.   56 In vivo detection of myocardial fibrosis using native T1ρ and T2* mapping in an animal model of chronic myocardial infarction
Joep van Oorschot1, Sanne Jansen of Lorkeers1, Fredy Visser2, Pieter Doevendans1, Johannes Gho1, Steven Chamuleau1, Peter Luijten1, and Jaco Zwanenburg1
1University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, 2Philips Healthcare, Best, Noord-Brabant, Netherlands

Native cardiac T2*- and T1ρ-mapping was performed in vivo in a porcine animal model of chronic myocardial infarction (MI), and correlated with in vivo gold standard LGE and ex vivo histology. A significant higher T1ρ relaxation time was found in the infarct region (61±11 ms), compared to healthy myocardium (36±4 ms), p<0.001. T2* was significantly lower in the infarct region (17±5 ms), compared to remote area (24±7 ms) (p<0.002). Iron staining showed an abundance of iron in the infarct area compared to remote myocardium, explaining the decrease in T2*. T1ρ-mapping is most promising for non-contrast enhanced detection of myocardial fibrosis.

4575.   57 Accelerate Free Breathing Cardiac Cine Imaging with Propeller and GRAPPA
Tsung-Lun Wu1, Ching-Lung Cheng2, Ming-Ting Wu3,4, Ming-Long Wu1,2, and Tzu-Cheng Chao1,2
1Department of Computer Science and Information Engineering, National Cheng-Kung University, Tainan, Taiwan, 2Institute of Medical Informatics, National Cheng-Kung University, Tainan, Taiwan, 3Department of Radiology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, 4School of Medicine, National Yang-Ming University, Taipei, Taiwan

Cardiac CINE imaging has been extensively used in routine exams and it typically requires breath-hold for better image quality. Therefore a free breathing protocol may help to ease the patient¡¦s burden in this exam. In the present work, a strategy integrating GRAPPA and PROPELLER was proposed to improve self-gated free breathing CINE imaging, which enables to acquire a larger blade for better image-based motion tracing while retaining temporal resolution and reducing scan time. And the results show that the present work can accomplish cardiac CINE imaging for a slice with acceptable quality in less than 1 minute.

4576.   58 FREE-BREATHING 3D LATE GADOLINIUM ENHANCEMENT MRI USING OUTER VOLUME SUPPRESSED PROJECTION NAVIGATORS
Rajiv G Menon1, G Wilson Miller2, Jean Jeudy1, Sanjay Rajagopalan3, and Taehoon Shin1
1Diagnostic Radiology and Nuclear Medicine, University of Maryland, Baltimore, Baltimore, MD, United States, 2Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, United States, 3Division of Cardiovascular Medicine, University of Maryland, Baltimore, Baltimore, MD, United States

The purpose of this study was to develop a free-breathing 3D Late Gadolinium Enhancement (LGE) Cardiac MR sequence and to test it on cardiac patients. The sequence consists of an Inversion pulse, Fat saturation, outer volume suppression as magnetization preparation followed by 1D projection navigators for motion correction, and 3D stack of spirals acquisition. The 3D LGE sequence and conventional 2D multi-slice breath-hold LGE were tested on 5 cardiac patients. Compared to conventional 2D LGE, the 3D LGE sequence gives better spatial coverage, less discomfort for patients, and takes less time, with comparable results. Testing on larger clinical cohort is under investigation.

4577.   59 MRI Assessment of Cardiac Function in Response to Exercise
Jacob Macdonald1, Omid Forouzan2, Jared Warczytowa2, Oliver Wieben1,3, Naomi Chesler2, and Christopher Francois3
1Medical Physics, University of Wisconsin - Madison, Madison, WI, United States, 2Biomedical Engineering, University of Wisconsin - Madison, Madison, WI, United States, 3Radiology, University of Wisconsin - Madison, Madison, WI, United States

The effect of exercise on cardiac function is important in the diagnosis of cardiovascular disease, but is clinically unavailable for MRI. In this pilot study, changes to cardiac function and aortic flow were investigated using specialized MRI-compatible exercise equipment that allowed healthy subjects to exercise in a supine position in the bore of the magnet. It was found that pulse wave velocity and cardiac output in the aorta, as well as ejection fraction and cardiac output in the left ventricle, showed statistically significant increases under exercise stress. Future studies will investigate the significance of these parameters in a diseased population.

4578.   60 Rapid ungated free-breathing cardiac MRI protocol
Edward DiBella1,2, Elwin Bassett3, Kyungpyo Hong2,3, Ganesh Adluru3, Devavrat Likhite3, Promporn Suksaranjit4, Brent Wilson4, Chris McGann4, and Daniel Kim2,3
1University of Utah, Salt Lake City, UT, United States, 2Bioengineering, University of Utah, Salt Lake City, Utah, United States, 3Radiology, University of Utah, Utah, United States, 4Cardiology, University of Utah, Utah, United States

Gating and breath-holding complicate acquisition of cardiac MRI data. A simpler streamlined pushbutton approach would significantly increase the clinical utility of cardiac MR. Methods for ungated acquisitions and retrospective self-gating were recently introduced. Here we propose and develop methods for a full CMR protocol (cine, perfusion, LGE, and T1/ECV mapping) that is ungated and free-breathing.

4579.   61 Real-time Heart MRI of the Mouse
Amir Moussavi1, Philipp R. Bovenkamp2, Verena Hoerr2, Cornelius Faber2, and Susann Boretius1
1Section Biomedical Imaging, Department of Radiology and Neuroradiology, Christian-Albrechts-University, Kiel, Germany, 2Institute of Clinical Radiology, University Hospital of Muenster, Muenster, Germany

Truly real-time imaging of mouse heart (temporal resolution = 41.25 ms, spatial resolution = 0.234 × 0.234 × 1.5 mm3) was accomplished by combining high field MRI and cyrocoil-technology with radial k-space encoding and nonlinear inverse reconstruction.

4580.   62 Cardiac Diffusion-Weighted MRI with Selective RF Excitation in a Single Breath-Hold
Mahdi Salmani Rahimi1, Dominik Fleischmann1, Anne Chin1,2, and Roland Bammer1
1Radiology, Stanford University, Stanford, CA, United States, 2Radiology, Centre hospitalier de l'Université de Montréal, Montreal, QC, Canada

Diffusion-weighted imaging of the heart is a challenging task due to signal losses associated with cardiac and respiratory movements. In this work, a restricted field of view RF excitation approach is combined with an automated timing mechanism to synchronize the diffusion encoding gradients with the most quiescent part of the cardiac cycle. Three small b-values and four large b-values were acquired during a single breath-holding period in healthy volunteers to probe the fast diffusing and slow diffusing compartments in the myocardium, respectively.

4581.   63 Whole-Heart T1 and Extracellular Volume Fraction Mapping with 6 Heartbeats
Sohae Chung1,2, Pippa Storey1,2, and Leon Axel1,2
1Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, United States, 2Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States

T1-mapping and the use of T1 changes from contrast enhancement for extracellular volume (ECV) quantification are clinically promising techniques for absolute quantification of myocardial fibrosis. However, whole-heart T1-mapping is rarely performed in clinical practice, due to the associated time-consuming data acquisition. Instead, it is usually performed at a single mid-ventricular level; this can lead to sampling error when the fibrotic process is not homogenous. Here, we present a rapid whole-heart T1-mapping in a single breath-hold of, e.g., 6 heartbeats (typically, 5-7 seconds for total 9 T1 maps) for the quantitative assessment of myocardial fibrosis.

4582.   64 A new method for quantification of aortic stiffness in vivo using magnetic resonance elastography (MRE): a translational study from sequence design to implementation in patients - permission withheld
Rachel Clough1, Ondrej Holub2, Henry Fok2, Nick Gaddum2, Jordi Alastruey2, and Ralph Sinkus2
1King's College London, London, London, United Kingdom, 2King's College London, London, United Kingdom

Aortic stiffness is an important risk factor for cardiovascular disease. Tonometry is the current standard but only provides spatially-averaged measurements. Assessment of specific aortic locations may be more important, particularly of the ascending aorta due the direct interaction this has with the heart. Magnetic resonance elastography measures material properties by studying the way shear waves travel through biological tissues. The aim of this study was to develop a new transducer-free MRE sequence to measure aortic stiffness in patients, using aortic valve closure, an intrinsic source for elastography, to generate shear waves in the aortic wall.

4583.   65 A novel imagery-based method for preoperative EVAR/TEVAR modeling: validation - video not available
Anou Sewonu1,2, Ramiro Moreno1,2, Olivier Meyrignac3, and Hervé Rousseau3
1I2MC, INSERM/UPS UMR 1048, Toulouse, France, 2ALARA Expertise, Strasbourg, France, 3Pôle imagerie, CHU Toulouse, Toulouse, France
 
The Multilayer Flow Modulator (MFM) has been introduced as an alternative minimal invasive treatment for arterial and aortic aneurysms. The concept of flow modulation is to reduce flow velocity and vorticity in the aneurysmal circulating volume, while improving laminar flow in collateral arteries. Although the concept had been proven, treatment in certain clinical cases was not conclusive. In this work, we demonstrate that a combination of pre-operatory velocity-encoded MRI and Computed Fluid Dynamics is an excellent tool for forecasting the becoming of a MFM stent graft.

4584.   66 New intrinsic frequency measures of cardiac function vs. cardiac MRI as a gold standard
Niema M. Pahlevan1,2, Thao T. Tran3, Peyman M. Tavallali4, Derek G. Rinderknecht5, Marie Csete6, and Morteza M. Gharib4
1Medical Engineering, California Institute of Technology, Pasadena, California, United States, 2Magnetic Resonance Spectroscopy, Huntington Medical Research Institute, Pasadena, California, United States, 3Magnetic Resonance Spectroscopy, Huntington Medical Research Institutes, Pasadena, CA, United States,4Graduate Aerospace Laboratory, California Institute of Technology, Pasadena, California, United States, 5Aerospace, California Institute of Technology, Pasadena, California, United States, 6Huntington Medical Research Institutes, Pasadena, CA, United States

We recently developed mechanical biomarkers of cardiovascular function, intrinsic frequencies (ω1 and ω2), calculated only from a carotid pulse waveform captured using an iPhone. We compare left ventricle ejection fraction (LVEF) derived from intrinsic frequencies vs. from cardiac MRI as a gold standard. LVEF computed from intrinsic frequency parameters and compared with LVEF measured from MRI. There was strong agreement between the LVEF measurements with average error of 9% and SD of 8%.

4585.   67 In vivo Cardiac MR Elastography on mouse
Yifei Liu1, Thomas J Royston1,2, and E Douglas Lewandowski3,4
1Department of Mechanical & Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois, United States, 2Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, United States, 3Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, Illinois, United States, 4Department of Physiology & Biophysics and Medicine (Cardiology), University of Illinois at Chicago, Chicago, Illinois, United States

Increased stiffness of the left ventricle (LV) wall is a contributing factor to the abnormal function associated with both impaired systolic and diastolic function during the progression of cardiomyopathies to overt heart failure. The mouse is a common animal model for studying the progression of cardiac pathologies and is readily for the application of MR Elastography, a non-invasive method to estimate stiffness of tissue. This study demonstrates the feasibility of in vivo cardiac MR Elastography (MRE) on the mouse heart to monitor myocardial stiffness, and the stiffness ratio between end-diastole and end-systole.

4586.   68 Simulation and Phantom Study of Wall Shear Stress in Arteriovenous Grafts
Daniel Beauchamp1,2, Steven G Lloyd3,4, Michael Allon3, Timmy Lee3, Nouha Salibi1,5, and Thomas S Denney Jr.1,2
1AU MRI Research Center, Auburn University, Auburn, Alabama, United States, 2Electrical and Computer Engineering, Auburn University, Auburn, Alabama, United States, 3Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States, 4VA Medical Center, Birmingham, Alabama, United States, 5MR R&D, Siemens Healthcare, Malvern, Pennsylvania, United States

Arteriovenous grafts (AVGs) used for hemodialysis vascular access have a high failure rate due to thrombosis arising from stenosis around the venous anastomosis. It is thought that this stenosis may result from patterns of low wall shear stress (WSS) in the anastomosis region. This study used CFD analysis and phase-contrast MRI scans of flow phantoms to examine WSS in a geometry resembling an AVG, in order to determine whether low WSS is in fact present in the region of frequent problematic stenosis formation. These techniques can potentially be used to predict and prevent graft failure due to thrombosis.

4587.   69 Myocardial steatosis and its association with obesity and regional ventricular dysfunction: Evaluated by magnetic resonance tagging and 1H spectroscopy in healthy African Americans
Chia-Ying Liu1, David A Bluemke1, Gary Gerstenblith2, Stefan L Zimmerman2, Ji li2, hong zhu3, Shenghan Lai2, and Hong Lai2
1Radiology and Imaging Sciences, NIH, Bethesda, MD, United States, 2Johns Hopkins School of Medicine, MD, United States, 3johns Hopkins School of Medicine, MD, United States

The objectives were to explore the factors that are associated with myocardial triglyceride, and to examine whether myocardial triglyceride is associated with ventricular function in healthy African Americans (AAs). Proton magnetic resonance spectroscopy was performed to noninvasively quantify myocardial triglyceride content on 92 AAs using a 3T MRI scanner. Obesity was shown to be associated with cardiac steatosis, and myocardial triglyceride content was shown to be associated with LV regional function in women. These findings suggest a link between obesity, cardiac steatosis, and subclinical cardiac dysfunction.

4588.   70 Dedicated Neonatal Cardiac Coil – Preliminary Results
Michael S Hansen1, Russel R Cross2, Laura J Olivieri1,2, Kendall O'Brien1,2, Hui Xue1, Matthew R DiPrimio3, Paul Taylor3, Tsinghua Zheng3, Xiaoyu Yang3, Matthew Finnerty3, and Peter Kellman1
1National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States, 2Children's National Medical Center, Washington, D.C., United States, 3Quality Electrodynamics, Mayfield Village, OH, United States

Neonatal cardiac MRI is typically done with general-purpose coils that are not optimized for cardiac imaging. With the aim of improving pediatric cardiac MRI, a twelve channel dedicated neonatal cardiac coil has been developed and is presented along with preliminary testing in phantoms and an in vivo imaging example. The coil enables parallel imaging with high parallel imaging factors and good g-factor performance. Real-time cine imaging with a temporal resolution of 40ms per frame is demonstrated in a small infant.

4589.   71 ECG and Navigator-Free 4D Whole-Heart Coronary MRA: Preliminary Comparisons with Conventional Protocols
Jianing Pang1, Behzad Sharif1, Zhaoyang Fan1, Xiaoming Bi2, Reza Arsanjani1, Daniel S Berman1, and Debiao Li1,3
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2MR R&D, Siemens Healthcare, Los Angeles, CA, United States, 3Medicine and Bioengineering, University of California, Los Angeles, California, United States

In this work, we perform preliminary comparisons between a recently proposed self-gated 4D coronary MRA technique, which offers simultaneous cardiac function and coronary imaging from a single measurement, with conventional cine and coronary MRA protocols. The cardiac function parameters obtained from the proposed technique are in good agreement with those from the conventional protocols. The coronary visualization quality of the proposed technique also compares favorably to the ECG-gated protocols.

4590.   72 Comprehensive morphological classification of bicuspid aortic valve by cine CMR in 368 patients.
Ian Gavin Murphy1, Alex J Barker2, Michael Markl2, Chris memorial Malaisrie3, Patrick M McCarthy3, Colleen memorial Clennon4, James C Carr1, and Jeremy Collins1
1Cardiovascular Imaging, Feinberg School of Medicine, Northwestern Memorial Hospital, CHICAGO, ILLINOIS, United States, 2Cardiovascular Imaging, Northwestern University, CHICAGO, ILLINOIS, United States, 3Cardiothoracic Surgery, Feinberg School of Medicine, Northwestern Memorial Hospital, CHICAGO, ILLINOIS, United States, 4Cardiothoracic Specialist Nurse, Feinberg School of Medicine, Northwestern Memorial Hospital, CHICAGO, ILLINOIS, United States

Bicupsid aortic valve has many phenotypes and the resulting haemodynamic disturbance may be associated with differing aortopathies. Using in plane cine bSSFP and PC imaging at the aortic valve, we present a robust and reproducible classification system for subcategorization of the aorti