Emily V.M Ward^1,2, Asad A Usman², Philip A Hodnett³, James C Carr², and Robert R Edelman^1
1Department of Radiology, Northshore University HealthSystem, Evanston Hospital, Chicago, Illinois, United States, ²Department of Radiology, Northwestern Memorial Hospital, Chicago, Illinois, United States, ³Department of Radiology, NYU Langone Center, New York, New York, United States

Our objective was to determine whether a rapid, non-contrast MRA technique might provide superior accuracy to ABI and reduce the need for additional imaging procedures prior to a revascularization procedure. Using CE-MRA as the reference standard, the sensitivity and specificity of ABI and non contrast QISS MRA for 50% or greater stenosis or occlusion was determined. Compared with ABI, QISS MRA provides higher accuracy for clinically relevant PAD and substantially reduces the requirement for additional imaging prior to a revascularization procedure. It has the potential to be an alternative screening examination to ABI for selected patients with PAD.

Eric M Bultman¹, Jessica Klaers², Christopher J François³, Mark L Schiebler³, Scott B Reeder^1,3, and Walter F Block^1,2
1Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, ²Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, ³Radiology, University of Wisconsin-Madison, Madison, WI, United States

The development of NCE-MRA methods to visualize the renal transplant vessels remains of tremendous clinical importance. In this retrospective study, we investigated the MR angiographic performance of a 3D radial sequence (VIPR-SSFP) compared to an inflow-weighted technique (IFIR) known to provide excellent visualization of the renal arteries. After identifying 21 renal transplant patients who received VIPR-SSFP and IFIR scans, two practicing radiologists scored these patients’ images on several criteria reflecting angiographic quality. Results demonstrate that VIPR-SSFP provides superior visualization of the renal veins and improved fat suppression, while IFIR provides somewhat superior visualization of the renal arteries.

Elise Bannier^1,2, Isabelle Corouge^1,2, Nicolas Wiest-Daesslé^1,2, Delphine Pelletier³, Pierre-Axel Lentz³, Antoine Larralde³, Bernard Langella³, Nashiely Pineda Alonso⁴, Jean-François Heautot³, and Valérie Croisé-Laurent^3,5
1Neurinfo Platform, University Hospital of Rennes, Rennes, France, ²INRIA, VisAGeS Project-Team, Rennes, France, ³Radiology Dept., University Hospital of Rennes, Rennes, France, ⁴Siemens Healthcare, Paris, France, ⁵Laboratoire IADI INSERM 947, CIC IT INSERM 807, University Henri Poincaré, Nancy, France

The aim of the study was to assess and quantify the ability of non contrast enhanced MRI to image peripheral vasculature and detect vascular abnormalities using an ECG-gated 3D T2 TSE NATIVE SPACE sequence in a 3T clinical setting.

Randall B. Stafford^1,2, M. Louis Lauzon^2,3, Mohammad Sabati⁴, Linda B Andersen^2,3, Houman Mahallati^2,5, and Richard Frayne^2,3
1Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada, ²Seaman Family MR Research Centre, Foothills Medical Centre, Calgary, Alberta, Canada,³Departments of Radiology and Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada, ⁴Department of Radiology, University of Miami, Miami, Florida, United States,⁵Department of Radiology, University of Calgary, Calgary, Alberta, Canada

This study compares the diagnostic quality of angiograms produced with traditional contrast-enhanced (CE) MRA and the bSSFP Dixon method for non-contrast-enhanced (NCE) MRA. Eight patients with clinically indicated CE renal MRA underwent the NCE examination a week later. A vascular radiologist scored the image quality from various renal artery segments from both examinations.

Kie Tae Kwon¹, Holden H Wu^1,2, Taehoon Shin¹, Tolga Çukur³, and Dwight G Nishimura^1
1Electrical Engineering, Stanford University, Stanford, CA, United States, ²Cardiovascular Medicine, Stanford University, Stanford, CA, United States, ³Helen Wills Neuroscience Institute, University of California at Berkeley, Berkeley, CA, United States

Non-contrast-enhanced flow-independent angiography (FIA) exploits intrinsic tissue parameters such as T1, T2 and chemical shift to generate vessel contrast. FIA can generate stable vessel contrast even with slow flow potentially in the diseased leg. Magnetization-prepared 3D SSFP sequences have been of interest for FIA, but an important issue with these sequences is artery-vein contrast. Recently, an efficient and robust 3D SSFP imaging sequence using a concentric cylinders k-space trajectory was developed. In this work, the 3D concentric cylinders trajectory was incorporated into a T2-prepared SSFP FIA sequence for scan-time reduction that can be traded off to improve the artery- vein contrast in the lower extremities.

Axel Bornstedt¹, Eberhard Hansis², Michael Grass³, Wolfgang Rottbauer¹, and Volker Rasche^1
1Internal Medicine II, University Hospital Ulm, Ulm, Germany, ²Philips Healthcare, ³Philips Research Europe

The acquisition of high resolution phase-contrast angiography is still limited by the long acquisition times. Considering the sparseness of the vascular structures, three-dimensional reconstruction techniques applied to X-ray angiography may be translated to MRI images. In this contribution, the acquisition of few projection images (thick-slab) of the vascular structures by phase-contrast MRI in combination with an iterative algorithm optimized for the reconstructing of sparse objects from few projection data by minimizing of the L1 norm of the reconstruction was tested for high-resolution phase-contrast MRA.

Tae han Kim¹, ung Jang¹, and Dosik Hwang^1
1Electrical & Electronic Engineering, Yonsei University, Seoul, Korea, Republic of

Susceptibility Weighted Imaging (SWI) method is commonly used for Magnetic Resonance (MR) venography. The difference between SWI and conventional GRE imaging is that phase information of signal is incorporated to enhance contrast of image. The phase can provide excellent contrast between venous blood vessels and other tissues with susceptibilities that are different from the background tissue. Although SWI is very powerful technique, SWI technique still has some weaknesses, regarding a trade-off between the gain of venous contrast and the loss of SNR. In this study, we propose a new approach to obtain high-contrast and high-SNR SWI venography with multiple echo datasets.

Ruud B van Heeswijk^1,2, Simone Coppo^1,2, Tobias Kober^2,3, and Matthias Stuber^1,2
1Department of Radiology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, VD, Switzerland, ²Center for Biomedical Imaging (CIBM), Lausanne, Switzerland,³Advanced Clinical Imaging Technology, Siemens Suisse SA - CIBM, Lausanne, Switzerland

While successful coronary vein imaging approaches using magnetization transfer contrast have been reported at 1.5 T, these techniques cannot easily be adopted at higher magnetic field strength because of specific absorption rate constraints. For these reasons, we have implemented a method that exploits T₂ shortening in deoxygenated blood. The hypothesis was tested whether this method enables contrast generation between the venous blood-pool and the surrounding structures at 3 T.

Andrew J Wheaton¹, and Mitsue Miyazaki^2
1Toshiba Medical Research Institute USA, Mayfield, OH, United States, ²Toshiba Medical Research Institute USA, Vernon Hills, IL, United States

Flow-sensitive dephasing (FSD) is a subtraction-based non-contrast MRA technique. Conventional FSD acquires two data sets at different flow-dephasing first moments (m1) and phases in the cardiac cycle. The m1 value must be carefully calibrated to avoid losing arterial signal or allowing venous contamination in the subtracted image. This study proposes a hybrid reconstruction method which incorporates a priori knowledge of the relationship between signal intensity and m1 / cardiac cycle in arteries and veins. Using multiple data sets (N=3) as input, the hybrid method improves arterial signal up to 100% while avoiding venous contamination as demonstrated in the lower leg.

Sandra Baumann¹, Michael Markl¹, and Ute Ludwig^1
1Dept. of Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany

The planning of bolus chase MR angiography (MRA) can be supported by the application of a vessel scout. Recently, the concept of a time-of-flight (TOF) vessel scout was presented which is based on the continuously moving table (CMT) acquisition and post processing of projection data. This study presents new acquisition and data processing strategies for CMT TOF vessel scout imaging which allow for improved vessel background contrast. A variable flip angle scheme was implemented to compensate for signal saturation caused by the repeated rf-excitation. Vessel contrast in scout images could further be increased by an autocorrelation analysis of acquired data.

Michael O. Zenge¹, Christopher Glielmi², Peter Weale², Ioannis Koktzoglou³, Robert R. Edelman³, Manuela Rick¹, Peter Schmitt¹, and Xiaoming Bi^2
1MR Applications Development, Siemens AG, Erlangen, Germany, ²Cardiovascular MR R&D, Siemens Healthcare, Chicago, IL, United States, ³Department of Radiology, NorthShore University HealthSystem, Evanston, IL, United States

Recently, quiescent-interval single-shot (QISS) peripheral MRA was introduced as a fast and robust approach for unenhanced MRA. Like any other multi-step MR imaging method QISS suffers from boundary artifacts at successive stations. Furthermore, the acquisition of adjustment and shimming parameters can be accelerated significantly in the moving table regime. Thus, continuous table movement was enabled for QISS and was compared to multi-step imaging in 5 healthy volunteers. In addition to comparable image quality as the multi-step approach, continuous table movement QISS reduces exam duration and complexity justifying further evaluation in patients.

Sebastian Schmitter¹, Edward J Auerbach¹, Gregor Adriany¹, Kamil Ugurbil¹, and Pierre-Francois Van de Moortele^1
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States

In Time-of-flight (TOF) angiography a contrast is generated between static tissues, partially saturated due to a high flip angle (&alpha=20-30º) with short TR<
 

Peter Schmitt¹, Michaela Schmidt¹, Manuela Rick¹, Michael O Zenge¹, Peter Weale², Xiaoming Bi², and Edgar Müller^1
1MR Application & Workflow Development, Siemens AG, Healthcare Sector, Erlangen, Germany, ²Cardiovascular MR R&D, Siemens Healthcare, Chicago, IL, United States

This work evaluates four different protocol approaches for IR-prepared b-SSFP non-CE MR angiography of the renal arteries: A standard labeling method with a single transverse inversion slab is compared versus a targeted V-shaped scheme, and an ECG-triggered, navigator-based approach with shorter TI versus a respiratory triggered strategy with longer TI. Image quality was found to improve from transverse to targeted labeling, and from shorter TI to longer TI, in particular in critical subjects with diminished blood flow conditions. The assessment of such problematic cases and optimizations towards a generic, robust and time-efficient solution will be the focus of further investigations.

Andew Nicholas Priest¹, Martin J Graves¹, and David J Lomas^1
1Department of Radiology, Addenbrookes Hospital and University of Cambridge, Cambridge, United Kingdom

Recent non-contrast-enhanced vascular imaging methods use velocity-sensitised preparation to suppress vascular signal, combined with subtraction of bright- and dark-blood images to generate angiograms and/or venograms; however separation of arteries and veins is imperfect. In this work, acceleration-dependent preparation was used to suppress arteries, leading to venograms with no apparent arterial contamination. Additionally, the influence of subject position on the quality of vein depiction was evaluated in the lower legs of 7 healthy volunteers. Prone orientation gave better image quality than supine orientation, possibly because it avoids compression of the veins, and was also better than ‘supported supine’ orientation. Additionally, the influence of subject position on vein image quality was evaluated in the lower legs of 7 healthy volunteers. Prone orientation gave better image quality than supine orientation, possibly because it avoids compression of the veins, and was also better than ‘supported supine’ orientation.

Stefan Haneder¹, Ulrike I Attenberger¹, Philipp Riffel¹, Thomas Henzler¹, Stefan O Schönberg¹, and Henrik J Michaely^1
1Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Mannheim, Germany

The purpose was to compare 3D non-enhanced ECG-gated inflow-dependent MRA (NE-MRA) vs. continuous table movement MR-angiography and time-resolved TWIST-MRA in the calf station at 3.0T in a clinical patient collective. Image qualities (IQ) and degree of stenoses were rated on a four point scale. Positive and negative predictive values, sensitivity and specificity for stenoses detection were calculated for overall graduation and severe stenoses. The results suggest that contrast-enhanced MRA techniques are superior to NE-MRA in terms of IQ and detection of stenoses. If technically successful, NE-MRA is characterized by a high NPV and overestimation of the degree of stenoses.

Ti-chiun Chang¹, Mariappan S. Nadar¹, Jens Guehring², Michael O. Zenge², Kai Tobias Block², Peter Schmitt², and Edgar Mueller^2
1Siemens Corporate Research, Princeton, NJ, United States, ²MR Applications Development, Siemens AG, Erlangen, Germany

: In the recent years, non-contrast magnetic resonance angiography (NCE MRA) has been an emerging tool in the diagnosis of degenerative vascular disease. Desired improvements include a reduction of the total scan time to reduce the impact of unintentional motion as well as an increase of the spatial and/or temporal resolution. Thus, the compressed sensing (CS) technique, which aims at reconstructing high quality signal from largely undersampled acquisitions, is a natural fit to further enhance time-resolved NCE-MRA applications

Ung Jang¹, and Dosik Hwang^1
1School of Electrical and Electronic Engineering, Yonsei University, Seoul, Korea, Republic of

MR venography (MRv) has an important role in diagnosis of venous diseases. Unlike x-ray or CT venography, MRv produces venographic images without any ionizing radiation. Obtaining venographic image with low noise and high contrast is clinically important for diagnosis of vascular diseases based on MRv. It has been reported that the best venography can be acquired at TE=28ms for veins in parallel to the static field of 3T while much longer TE is needed for the veins not parallel to the static field. However, such a long TE would result in lower signal-to-noise ratio (SNR) in MRv image since the signals from veins and other tissues drastically decay with time. Therefore, reducing noise at longer TE is important in order to acquire a clinically meaningful venography. Employing conventional spatial filters such as low-pass filter, median filter, and anisotropic diffusion filter are typical denosing methods. Although such spatial filters reduce noise, they also smooth out the details of images such as small structures and edges, or introduce an artificial appearance such as stair-casing artifact due to nonlinear process. These degradations of image quality resulted from interference of neighbor pixels. The aim of this study is to obtain high-quality venography at longer TE without introducing blurring effects or any artificial appearance, by reducing noise on temporal domain of 3D multi-echo datasets.

Avinash Kali¹, Andreas Kumar², Xiangzhi Zhou³, Veronica L M Rundell³, Ying Liu³, Rachel A Klein³, Richard L Q Tang³, and Rohan Dharmakumar^3
1Biomedical Engineering, Northwestern University, Chicago, IL, United States, ²Department of Medicine, Laval University, Quebec, QC, United States, ³Radiology, Northwestern University, Chicago, IL, United States

T2 and T2* changes associated with myocardial hemorrhage in the setting of ischemia-reperfusion injury were examined and the effectiveness of the two mapping techniques in discriminating hemorrhage was evaluated using a canine model. T2* of hemorrhagic infarctions were significantly lower than those of non-hemorrhagic infarctions and remote myocardium. T2s of both hemorrhagic and non-hemorrhagic infarctions were significantly elevated with respect to remote myocardium, likely due to the high sensitivity of T2 to myocardial edema. We conclude that T2* maps are more effective at discriminating hemorrhage, while T2 maps are more effective at detecting myocardial edema post ischemia-reperfusion injury.

Thomas Elgeti¹, Mark Beling², Sebastian Hirsch¹, Bernd Hamm¹, Jürgen Braun³, and Ingolf Sack^1
1Department of Radiology, Charité Universitätsmedizin Berlin, Berlin, Germany, ²Department of Cardiology, Angiology, Pulmonology, Charité Universitätsmedizin Berlin, Berlin, Germany,³Institute of Medical Informatics, Charité Universitätsmedizin Berlin, Berlin, Germany

MR Elastography (MRE) relies on excitation and measurement of shear-waves in soft tissue. Cardiac MRE was performed in 4 groups: young and old healthy volunteers and patients with mild and severe diastolic dysfunction. Several elasticity-based parameters were measured. In diastolic dysfunction the amplitudes of externally induced shear waves were lower than in healthy controls. Furthermore, elasticity determined cardiac time intervals were altered similar to echocardiographic derived time intervals. Cardiac MRE allows measuring elasticity parameters of the left ventricular myocardium associated with physiological aging and relaxation abnormalities.

Ya Chen¹, Kevin Payne¹, Bharath Atthe¹, Akemichi Baba², Toshio Matsuda², and Xin Yu^1
1Department of Biomedical Engineering and Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, United States, ²Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan

The present study aimed at investigating whether manganese-enhanced MRI (MEMRI) is also sensitive to changes in Na+-Ca2+ exchanger (NCX) activity. Using a rapid T1-mapping method, we investigated the dynamics of R1 changes in manganese-perfused rat hearts with and without NCX inhibition by SEA0400.

Tri Minh Ngo¹, George S. K. Fung², Benjamin M.W. Tsui^1,2, Elliot McVeigh¹, and Daniel A. Herzka^1
1Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland, United States, ²Division of Medical Imaging Physics, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland, United States

We present a framework which enables realistic 3-D digital phantoms of organs such as the brain and heart to be constructed from polyhedra which have an analytical Fourier transform. Using this framework and data provided by the 4-D eXtended CArdiac Torso (XCAT) phantom, we constructed an anatomically realistic 4-D phantom of the beating heart represented analytically in the k-space and image domains. We used the phantom to simulate motion artifacts observed in 3-D cine acquisitions at different temporal resolutions. This phantom provides a physiologically realistic gold standard permitting the exploration and optimization of acquisition, motion compensation, and reconstruction strategies.

Bhairav Bipin Mehta¹, Xiaodong Zhong², and Frederick H Epstein^1
1Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, ²MR R&D Collaborations, Siemens Healthcare, Atlanta, Georgia, United States

Quantitative imaging of myocardial motion and strain is growing importance. 3D cine DENSE MRI can be advantageous for complete assessment of myocardium. One of the drawbacks of 3D cine DENSE MRI is a long acquisition time. Using the outer volume suppression property of stimulated echoes the scan time was reduced approximately by one third.

Bernd André Jung¹, Erica Dall'Armellina², Stefan Neubauer², Michael Markl¹, and Jurgen E Schneider^2
1Dept. of Radiology, Medical Physics, University Medical Center, Freiburg, Germany, ²Dept. of Cardiovascular Medicine, University of Oxford, United Kingdom

Tissue Phase Mapping is a well-established technique to assess regional cardiac function in humans. In mice, regional time course of the radial, rotational and longitudinal velocity components of the myocardium have not been systematically analyzed to date. The aim of our study was to perform a comprehensive quantitative analysis of myocardial wall motion in normal mice compared to velocity patterns in human hearts. Motion patterns of normal mouse hearts were similar to the human heart; however, distinct differences in regional myocardial motion were observed that might have to be considered when adapting myocardial mouse models to humans.

Sean C Forbes¹, Larry T Bish², Meg M Sleeper³, Wil Mai⁴, H Sweeney², and Glenn A Walter^5
1Department of Physical Therapy, University of Florida, Gainesville, FL, United States, ²Department of Physiology, University of Pennsylvania, Philadelphia, PA, ³Department of clinical studies, University of Pennsylvania, Philadelphia, PA, ⁴School of Veterinary Medicine, University of Florida, Philadelphia, PA, ⁵Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL

Cardiac dysfunction is prevalent in Duchenne’s muscular dystrophy (DMD), with heart failure a common cause of death. Unfortunately, there is presently no cure or effective treatment for DMD. This study implements a novel approach of exon skipping by using viral mediated delivery of a modified U7 snRNA carrying antisense sequence to correct the disrupted reading frame in Golden Retriever muscular dystrophy (GRMD) dogs. The results indicate increased dystrophin expression and improved regional left ventricular strain values. Thus, AAV-mediated delivery of a U7 exon skipping construct shows promise as a cardiac therapeutic intervention for DMD.

Bernd Jung¹, Nadine Beetz², Michael Markl¹, Annette Merkle¹, Lutz Hein², and Dominik von Elverfeldt^1
1Dept. of Radiology Medical Physics, University Medical Center, Freiburg, Germany, ²Dept. Phamacology 2, Institute for Pharmacology, Freiburg, Germany

Cardiac loading can initiate hypertrophy. The factors identifying patients benefiting from a load removal are still not fully understood. Therefore, the mechanisms of remodeling after cardiac unloading are of high interest for therapeutic intervention. Mouse models of experimentally increased cardiac loading/unloading can provide an important tool to investigate cardiac remodeling and recovery. Small animal MRI has proven to be a useful tool for the evaluation of cardiac functional parameters. The aim of this work was to monitor changes in aortic diameter and regional cardiac function during remodeling and recovery after experimental myocardial loading by aortic stenosis using MRI and ultrasound.

Sahar Soleimanifard¹, Khaled Z. Abd-Elmoniem², Emi Z. Murano¹, M. R. Abraham¹, Theodore P. Abraham¹, and Jerry L. Prince^1
1The Johns Hopkins University, Baltimore, MD, United States, ²National Institute of Diabetes and Digestive and Kidney Disease, Bethesda, MD, United States

Assessment of viability in myocardial disease continues to be of interest to clinicians. Principal strain patterns have been shown to change with ischemic injury, and can provide a sensitive index of viability. However, clinical use of principal orientations is extremely rare due to the existing noise in current measurements of angles. In this work, a reliable method of measuring principal strain angles was proposed. Consistency of the angles in the normal myocardium, combined with the results in the dysfunctional tissue in a porcine model, confirms the potential of principal strain orientations in assessment of viability.

June Cheng-Baron¹, Michael D Nelson², Corey R Tomczak³, Kelvin Chow¹, Justin A Ezekowitz⁴, Mark J Haykowsky³, D Ian Paterson⁴, and Richard B Thompson^1
1Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada, ²Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Alberta, Canada,³Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada, ⁴Division of Cardiology, University of Alberta, Edmonton, Alberta, Canada

We propose surrogates for global longitudinal, circumferential, and radial strains that can be measured from SSFP images based on the change in endocardial and epicardial borders over the entire left ventricle, with minimal additional post-processing. These metrics are compared in controls and patients with a wide range of ejection fractions and with literature values for each strain component. In controls, these metrics agree with literature values. In the patients with preserved ejection fractions, longitudinal function was lower than controls despite no measured difference in EF, circumferential, or radial function. The fractional longitudinal contribution to EF declines with impaired EF.

Kieren G Hollingsworth¹, Grainne S Gorman², Michael I Trenell¹, Robert McFarland², Robert W Taylor², Douglass M Turnbull², Guy A MacGowan³, Patrick F Chinnery⁴, and Andrew M Blamire^1
1Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom, ²Mitochondrial Research Group, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom, ³Department of Cardiology, Freeman Hospital, Newcastle upon Tyne, Tyne and Wear, United Kingdom, ⁴Institute of Human Genetics, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom

Cardiomyopathy causes morbidity and mortality in m3243A>G mutation carriers. It remains controversial how early cardiac hypertrophy and dysfunction occur. 10 m3243A>G mutation carriers and 16 age- and gender-matched control subjects were recruited: anatomical MRI allowed assessment of left ventricular size and systolic function: cardiac tagging was used to assess torsion and regional myocardial strains. Mutant mtDNA load was measured by muscle biopsy. Concentric left ventricular hypertrophy was found in the absence of systemic hypertension, and LV index was found to discriminate hypertrophy better than LV mass. Mutation carriers had a re-orientation of myocardial strains which correlated with mutation load.

Shinichi Takase¹, Andreas Sigfridsson², and Hajime Sakuma^3
1Department of Radiology, Mie University Hospital, Tsu, Mie, Japan, ²IMH/Cardiovascular Medicine, Linkoping University, Linkoping, Sweden, ³Department of Radiology, Mie University, Tsu, Mie, Japan

DENSE MR images were acquired in 10 volunteers within reduced scan time of 9 RR intervals by using spiral acquisition. The image quality with this approach was comparable to that by conventional 18 RR acquisitions, with peak Lagrangian strain of -0.20+/-0.03 for both methods. The bias between two methods for quantifying strain was 0.000, with 95% limits of agreement of �}0.04. Spiral DENSE MRI acquired in 9 RR intervals is useful for patients who cannot hold their breath for 18 RR intervals, and may enable to use DENSE for stress imaging which is especially demanding for short breath holding time.

Kevin J Koomalsingh¹, Chun Xu¹, Larry Dougherty², Masahito Minakawa¹, Takashi Shuto¹, Joseph H Gorman, III¹, Robert C Gorman¹, and James J Pilla^1
1Surgery, University of Pennsylvania, Glenolden, PA, United States, ²Radiology, University of Pennsylvania, Philadelphia, PA, United States

We evaluated the effect of an adjustable pressure device in a well developed large animal myocardial infarction model using 3D SPAMM tagging and optical flow mapping for data analysis.

Feng Huang¹, Wei Lin¹, George Randy Duensing¹, and Arne Reykowski^1
1Invivo Corporation, Gainesville, Florida, United States

k-t GRAPPA has been proposed for dynamic imaging with high reduction factors. In this work, GRAPPA operator and narrow window data sharing are used to significantly improve the accuracy and reconstruction speed of k-t GRAPPA. The enhanced version is called the second generation (2G) k-t GRAPPA. Experiments with cardiac cine data set shows that the 2G k-t GRAPPA can produce images with lower error using shorter reconstruction time than k-t GRAPPA, and a compressed sensing technique in k-t space (k-t FOCUSS).

Candida Laura Desjardins¹, Yong Chen², Julian Stelzer¹, and Xin Yu^2,3
1Physiology, Case Western Reserve University, Cleveland, OH, United States, ²Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, ³Case Center for Imaging Research, University Hospitals, Cleveland, OH, United States

This study investigated the biomechanical consequences of altering the contractile properties and structural stability of cardiac myocytes. Myocardial wall strain and torsion were quantified in mouse models of hypertrophic and dilated cardiomyopathy using DENSE MRI. The amplitude and time course of strain and torsion development was severely altered in mice with complete deletion of myosin binding protein-C (cMyBP-C) or muscle LIM protein (MLP). In addition, the heterozygous cMyBP-C mice showed normal global function but decreased strain and torsion, suggesting the sensitivity of DENSE MRI in detecting subtle changes in contractility at an early stage of disease progression.

Stefan Maderwald¹, Stephan Orzada^1,2, Zimin Lin³, Lena C. Schäfer^1,2, Andreas K. Bitz^1,2, Oliver Kraff¹, Irina Brote^1,2, Lars Häring³, Andreas Czylwik³, Michael O. Zenge⁴, Susanne C. Ladd^1,2, Mark E. Ladd^1,2, and Kai Nassenstein^1,2
1Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany, ²Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany, ³Department of Communication Systems, University of Duisburg-Essen, Essen, Germany, ⁴MR Application Developement, Siemens AG, Erlangen, Germany

The inherently higher signal-to-noise ratio and certain enhanced soft tissue contrasts at 7T compared to 1.5T or even 3T MRI might improve image quality in selected imaging applications such as high-resolution cardiac MRI in humans. A number of artifacts and imaging constraints related to 7T transmit/receive problems have been addressed in previous work. However, a major issue is still the generation of a strong, reliable trigger signal. In this study we use an optoacoustic microphone and a DSP card for signal detection and trigger generation. Volunteers and a patient with known chronic myocarditis, pericardial effusion, and mild arrhythmia were scanned and evaluated.

J. Tim Marcus¹, Gert Jan Mauritz², T. Kind², Marielle van de Veerdonk², Nico Westerhof², and Anton Vonk-Noordegraaf^2
1Physics & Medical Technology, VU University Medical Center, Amsterdam, Netherlands, ²Pulmonary Diseases, VU University Medical Center, Amsterdam, Netherlands

The changes of right ventricular (RV) geometric shortening in surviving (n=26) and non-surviving (n=16) Pulmonary Arterial Hypertension (PAH) patients were studied. RV longitudinal shortening, transverse shortening and RV fractional area change (RVFAC) were measured on 4-chamber cardiac MRI cine images. These values remained the same in the survivors, but transverse shortening and RVFAC decreased further in the non-survivors at 1 year follow-up (p<0.05). This decrease in RVFAC was associated with loss of RV ejection fraction (p=0.005). Thus, non-surviving PAH patients are characterized by a continued decline in RV transverse shortening and in RVFAC, while RV longitudinal shortening remains the same.

Mehmet Ersoy^1,2, Melanie S Kotys³, Xiaopeng Zhou^1,2, George P Chatzimavroudis², and Randolph M Setser^1
1Imaging Institute, Cleveland Clinic, Cleveland, Ohio, United States, ²Cleveland State University, Cleveland, Ohio, United States, ³Philips Healthcare, Cleveland, Ohio, United States

The purpose of this study was to design and build a low-cost, non-ferromagnetic LV motion phantom for use with cardiac MRI that is able to produce physiologically realistic LV wall thickening and rotation. Wall motion and rotation are modeled using separate phantoms housed within a common enclosure. The phantoms are easy to assemble and are constructed entirely of non-ferromagnetic materials, Results were physiologically realistic and reproducible, with standard deviations below 1.7% for strain and 1.1° for rotation. These phantoms could be of benefit when developing new cardiac MRI techniques and could potentially reduce development costs.

Tobias Wech¹, Angela Lemke², Debra Medway², Lee-Anne Stork², Craig A Lygate², Stefan Neubauer², Herbert Köstler¹, and Jürgen E Schneider^2
1Institute of Radiology, University of Wuerzburg, Wuerzburg, Bavaria, Germany, ²Cardiovascular Medicine, University of Oxford, Oxford, Oxon, United Kingdom

Cine-MRI is a well-established tool to assess global cardiac function in rodent models of cardiovascular disease. The aim of this study was to validate compressed sensing as an approach to accelerate cine-MRI in mice at 9.4T. Fully sampled data cine sets acquired in normal and chronically infarcted mice were 2-, 2.5-, 3- and 4-fold undersampled in post-processing and subjected to compressed sensing reconstruction. Blinded segmentation of all data showed that 3-fold acceleration is possible without impairing accuracy of left-ventricular volume and mass measurements.

Alejandro Roldán-Alzate¹, Heidi B Kellihan², Daniel W Consigny¹, Eric J Niespodzany¹, Christopher J François¹, Oliver Wieben^1,3, Naomi C Chesler⁴, and Alex Frydrychowicz^1
1Radiology, University of Wisconsin, Madison, WI, United States, ²Veterinary Medicine, University of Wisconsin, Madison, WI, United States, ³Medical Physics, University of Wisconsin, Madison, WI, United States, ⁴Biomedical Engineering, University of Wisconsin, Madison, WI, United States

The hemodynamics in pulmonary arterial hypertension (PAH) and mechanisms of associated heart failure are not well understood. Non-invasive imaging techniques enable qualitative and quantitative assessment ofcardiopulmonary status during PAH progression. We hypothesized that large that 4D velocity (MRI) could be effectively used to visualize hemodynamics in a dog model of acute PAH and assess right ventricular (RV) function. In addition, we hypothesized that pulmonary artery stiffening with PAH would alter blood flow patterns. Results demonstrate a significant increase in PA stiffness as determined by relative area change measurements and altered hemodynamics that provide a potential mechanism for RV dysfunction.

Zhe Wang^1,2, Abbas N Moghadam^2,3, Meral Reyhan^2,4, J Paul Finn^2,4, and Daniel B Ennis^1,2
1Biomedical Engineering Interdepartmental Program, University of California, Los Angeles, CA, United States, ²Department of Radiological Sciences, Diagnostic Cardiovascular Imaging Section, University of California, Los Angeles, CA, United States, ³Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran, ⁴Biomedical Physics Interdepartmental Program, University of California, Los Angeles, CA, United States

Radial tags have advantage for the measurement of left ventricle (LV) contraction and myocardial torsion compared with conventional line or grid SPAtial Modulation of Magnetization (SPAMM) tags due to the gross annular geometry of left ventricles. Complementary SPAMM (CSPAMM) with ramped imaging flip angles provides a way to maintain relatively uniform tag contrast throughout the whole cardiac phase. We combine the CSPAMM technique with radial tag encoding and demonstrate the sequence in simulations, images in phantoms, and a normal healthy subject. Complementary radial tags obviously increases the apparent contrast of the tags in late phases of the cardiac cycle and enables estimates of circumferential and radial strain. LV torsion and radial-circumferential shear strain with a pattern that is better matched to the LV geometry and may enable more facile assessment of LV regional function

Thomas Elgeti¹, Dietmar E. Kivelitz², Dirk Habedank³, Bernd Hamm¹, Rainer Röttgen¹, and Diane Miriam Renz^1
1Department of Radiology, Charité Universitätsmedizin Berlin, Berlin, Germany, ²Albers-Schönberg-Institut für Strahlendiagnostik, AK St. Georg, Hamburg, Germany, ³Department of Cardiology, Charité Universitätsmedizin Berlin, Berlin, Germany

A comprehensive cardiac magnetic resonance imaging (CMRI) approach was evaluated retrospectively in 6 patients with peripartum cardiomyopathy (PPCM). This is a rare, possible life-threatening cardiac disorder, which affects previously healthy women in the last month of pregnancy or within five months after birth. The MR-protocol included SSFP images (functional analysis), T2 weighted images (edema), early (reflecting increased capillary leakage) and late gadolinium enhancement (LGE; irreversible myocardial injury). Using this protocol, myocardial inflammation is detected the acute phase of the disease. In most patients, these changes are transient. If LGE is found, the patient’s clinical course may not be favourable.

Yijen Lin Wu¹, Qing Ye¹, Fang-Cheng Yeh^1,2, Brent D Barbe¹, Lesley M Foley¹, Li Liu¹, T Kevin Hitchens¹, and Chien Ho^1,3
1Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, PA, United States, ²Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States, ³Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, United States

The aim of this study to investigate the potential of integrated cardiac MRI (CMR) protocols for better assessment and diagnosis of coronary artery disease (CAD), especially for acute coronary syndrome (ACS). Our data indicate that integrated CMR with tagging and perfusion to assess myocardial perfusion and regional wall motion simultaneously might be valuable for better assessment of myocardial status after myocardial infarction, and can better assist early evaluation of ACS. In addition, we observed macrophage infiltration shortly after ischemic injury, suggesting inflammation plays a role in ischemia-reperfusion injury.

Lucas Abraham Citro¹, Sarah E. Sansom², Mahmood Khan^2,3, Mickey Mizzell Martin², Periannan Kuppusamy^1,2, and Terry S. Elton.^2,4
1Internal Medicine, The Ohio State University, Columbus, Ohio, United States, ²Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio, United States, ³Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University, Columbus, Ohio, United States, ⁴College of Medicine, Department of Pathology, The Ohio State University, Columbus, Ohio, United States

We have utilized cardiac magnetic resonance imaging, for the first time, to assess the cardiac functional defects of the left (LV) and right ventricles (RV) of Ts65Dn mice, the most-studied murine model of Down syndrome. Using a vertical-bore 11.7T MRI system, T1-weighted gradient echo FLASH-cine images were acquired to examine ventricular function and interventricular septal volume. The Ts65Dn mice showed significant decreases in LV ES and ED mass, EDV, ESV, SV, ED RV mass, and ED IVS volume. These results suggest that the extensive cardiac functional abnormalities present in Ts65Dn mice can be detected using high-field cardiac magnetic resonance imaging.

Wouter Oosterlinck¹, Tom Dresselaers², Vincent Geldhof¹, Uwe Himmelreich², and Paul Herijgers^1
1Experimental Cardiac Surgery, K.U.Leuven, Leuven, Belgium, ²Biomedical NMR unit - MoSAIC, K.U.Leuven, Leuven, Belgium

The prevalence and consequences of diabetes mellitus type 2 and the metabolic syndrome contribute to the increasing morbidity and mortality from ischemic heart disease. Experimental animal models allow us to evaluate disease progression and new treatment options. We used cardiac cine MRI (cMRI) and left ventricular (LV) pressure conductance (PC) analysis to study cardiac function in an experimental model of the metabolic syndrome (DKO mice [1], both leptine and LDL receptor deficient, leading to obesity, diabetes mellitus type 2 and dyslipidemia). The aims of our study were: (1) to compare PC and MRI volumetric information and (2) to determine which contractility parameters were altered in the DKO mice at 24 weeks.

Yijen Lin Wu¹, Qing Ye¹, Brent D Barbe¹, Fang-Cheng Yeh^1,2, Lesley M Foley¹, Li Liu¹, T Kevin Hitchens¹, and Chien Ho^1,3
1Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, PA, United States, ²Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States, ³Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, United States

The aim of this study is to establish integrated cellular and functional MRI parameters for various stages of acute and chronic rejection, in searching for possible non-invasive surrogate indicators with MRI that could potentially translate to clinical arena. Our data indicated that the allograft rejection, both acute and chronic forms, appears to be highly heterogeneous. Regions with compromised functions also show more macrophage infiltration. Multiple MRI parameters provide further accuracy in rejection evaluation. Detailed profiling and modeling of the temporal and spatial relationship of the integrated multi-parameter MRI may be useful in establishing surrogate markers for detecting rejection.

Frank Kober¹, Alexis Jacquier¹, Soksithikun Bun¹, Patrick J Cozzone¹, and Monique Bernard^1
1Centre de Resonance Magnetique Biologique et Medicale, Faculte de Medecine, Universite de la Mediterraneee, Marseille, Provence, France

In earlier studies, myocardial blood flow reserve was assessed using ASL in rats under pentobarbital, known to depress cardiac function. Here, MBF reserve was quantified in isoflurane-anesthetized rats using Look-Locker FAIR gradient-echo (LLFAIRGE) ASL. Results were compared with fluorescent microspheres (FM). Myocardial ASL was performed at rest and during adenosine infusion (140µg/kg/min). MBF reserve measured using LLFAIRGE-ASL was 2.5±0.6 and not significantly different from FM (2.4±0.9). MBF reserve was significantly higher than that earlier obtained under pentobarbital. The finding of significant MBF reserve using isoflurane is important, since this anesthetic is commonly used in imaging experiments.

John David Biglands¹, Abdulghani Larghat², Sven Plein², Derek R Magee³, Roger D Boyle³, and Aleksandra Radjenovic^4,5
1Division of Medical Physics, University of Leeds, LEEDS, Yorkshire, United Kingdom, ²Division of Cardiovascular & Neuronal Remodelling, University of Leeds, LEEDS, Yorkshire, United Kingdom,³School of Computing, University of Leeds, LEEDS, Yorkshire, United Kingdom, ⁴School of Medicine, University of Leeds, LEEDS, Yorkshire, United Kingdom, ⁵Academic Section of Musculoskeletal Disease, University of Leeds, LEEDS, Yorkshire, United Kingdom

Estimating myocardial blood flow (MBF) from DCE-MRI cardiac perfusion datasets requires contouring of the myocardium. This study aimed to investigate the effect of myocardial contour error on estimated MBF with a view to defining a suitable target accuracy level. MBF values were estimated from concentration vs. time curves from 16 volunteers using manually drawn contours. Erroneous contours were simulated by allowing the manual contours to deviate by up to half the mean myocardial width from the ‘true’ manual reference. Statistically significant errors weren’t induced in MBF with contour errors allowed to deviate up to 0.4 of the mean myocardial width.

John David Biglands¹, Abdulghani Larghat², Sven Plein², Derek R Magee³, Roger D Boyle³, and Aleksandra Radjenovic^4,5
1Division of Medical Physics, University of Leeds, LEEDS, Yorkshire, United Kingdom, ²Division of Cardiovascular & Neuronal Remodelling, University of Leeds, LEEDS, Yorkshire, United Kingdom,³School of Computing, University of Leeds, LEEDS, Yorkshire, United Kingdom, ⁴School of Medicine, University of Leeds, LEEDS, Yorkshire, United Kingdom, ⁵Academic Section of Musculoskeletal Disease, University of Leeds, LEEDS, Yorkshire, United Kingdom

Estimating myocardial blood flow (MBF) from DCE-MRI datasets requires contours to be drawn outlining the myocardium. Manual contouring is time consuming and numerous automated contouring algorithms have been developed. A variety of metrics are employed to evaluate such algorithms in terms of either geometric contour errors or errors in the estimated MBF. This study aimed to establish the relationship between a selection of geometric distance metrics and MBF error and found that these measures did not correlate. Future automated myocardial contouring algorithms should be evaluated in terms of both geometric distance metrics and MBF to enable objective cross-comparison.

Steven Sourbron¹, William Morton¹, David L Buckley¹, John P Greenwood², and Sven Plein^2
1Division of Medical Physics, University of Leeds, Leeds, United Kingdom, ²Division of Cardiovascular and Neuronal Remodelling, University of Leeds, Leeds, United Kingdom

Measurement of myocardial blood flow (MBF) with DCE-MRI is conventionally performed on a region-of-interest (ROI) basis. In principle a voxelwise analysis is more attractive, but the lower SNR of single-voxel curves may reduce the accuracy or precision. This study aimed to investigate in patient data (n=25) whether voxelwise MBF values are significantly different from an analysis on ROI basis. Results show that both are in very good agreement, with a systematic difference of 4%. Since a voxelwise analysis offers additional information on the heterogeneity of myocardial perfusion, these results provide a strong case for the voxelwise approach in clinical applications.

Robert Manka^1,2, Cosima Jahnke³, Peter Boesiger¹, Thomas F. Lüscher², Ingo Paetsch³, and Sebastian Kozerke^1
1Institute for Biomedical Engineering University and ETH Zürich, Zürich, Switzerland, ²Cardiology, Unispital Zürich, Zürich, Switzerland, ³Cardiology, University Hospital RWTH Aachen, Aachen, Germany

3D-CMR stress perfusion offers high quality and high diagnostic accuracy for the detection myocardial ischemia.

David L Buckley¹, John D Biglands¹, Abdulghani Larghat², Steven P Sourbron¹, Aleksandra Radjenovic³, John P Greenwood², and Sven Plein^2
1Division of Medical Physics, Leeds Institute of Genetics, Health and Therapeutics, University of Leeds, Leeds, West Yorkshire, United Kingdom, ²Division Cardiovascular & Neuronal Remodelling, Leeds Institute of Genetics, Health and Therapeutics, University of Leeds, Leeds, West Yorkshire, United Kingdom, ³Section of Musculoskeletal Disease, Leeds Institute of Molecular Medicine, University of Leeds, Leeds, West Yorkshire, United Kingdom

The purpose of this study was to estimate microvascular function in the myocardium at rest and under adenosine stress using dynamic contrast-enhanced MRI and to establish whether transport of Gd-DTPA was perfusion-limited. 16 healthy volunteers underwent myocardial perfusion imaging at stress and rest. Data were analyzed to provide estimates of myocardial perfusion, blood volume, capillary permeability-surface area product (PS) and interstitial volume. Delivery of Gd-DTPA at rest was close to perfusion-limited while this was not the case under stress. In addition to a 3-fold increase in perfusion, the effect of adenosine was to increase blood volume and PS.

Terrence Jao¹, Zungho Zun², Padmini Varadarajan³, Ramdas Pai³, and Krishna Nayak^2
1Keck School of Medicine, University of Southern California, Los Angeles, California, United States, ²Electrical Engineering, University of Southern California, Los Angeles, California, United States, ³Division of Cardiology, Loma Linda University Medical Center, Loma Linda, California, United States

Arterial spin labeled MRI is an emerging approach for measuring myocardial perfusion and perfusion reserve in humans. The technique requires acquisition and registration of multiple tagged and control images and suffers from low signal-to-noise ratio. In this work, we address these two challenges by spatially aligning and spatio-temporally filtering myocardial ASL data in a polar coordinate frame. We demonstrate that this approach facilitates assessment of regional perfusion and perfusion reserve in patients.

Daniel Stäb¹, Felix A. Breuer², Christian Oliver Ritter¹, Dietbert Hahn¹, and Herbert Köstler^1
1Institute of Radiology, University of Würzburg, Würzburg, Bavaria, Germany, ²Research Center Magnetic Resonance Bavaria, Würzburg, Germany

Applying CAIPIRINHA with an acceleration factor higher than the number of simultaneously acquired slices allows accelerating the imaging procedure in slice and phase encoding direction. With this Parallel Imaging approach myocardial perfusion imaging can be performed with whole heart coverage and high spatial resolution. 12 slice first pass in-vivo examinations are demonstrated, showing excellent image quality at a high spatial resolution of 2.0 x 2.0 mm². Being easy to implement and providing short reconstruction times, the technique is suitable for application in clinical routine.

Daniel Stäb¹, Johannes Tran-Gia¹, Christian Oliver Ritter¹, Dietbert Hahn¹, and Herbert Köstler^1
1Institute of Radiology, University of Würzburg, Würzburg, Bavaria, Germany

Saturation prepared quantitative myocardial perfusion imaging particularly depends on an exact determination of the arterial input function (AIF). However, for typical contrast agent doses and recovery times TI between magnetization preparation and image acquisition, this is hampered by saturation effects. Utilizing a model constrained image reconstruction algorithm in conjunction with radial data acquisition, one complete image can be reconstructed for every single acquired radial projection; i.e. every corresponding TI. Hence, the technique allows determining a non-saturated AIF (short TI) and the conventional images (long TI) within one single scan.

Aleksandra Radjenovic^1,2, John Biglands¹, Abdulghani Larghat¹, John Ridgway¹, John Greenwood¹, and Sven Plein^1
1School of Medicine, University of Leeds, Leeds, United Kingdom, ²Academic Section of Musculoskeletal Disease, University of Leeds, NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, United Kingdom

In this study, we analysed the systematic differences between left ventricular arterial input function (AIF) curves acquired in different parts of the cardiac cycle, and assessed the impact of these differences on the estimated values of myocardial blood flow (MBF) in 17 healthy volunteers. Diastolic AIF precedes the systolic AIF at rest and stress, and diastolic AIF is more compact (with higher amplitude and shorter time to peak). Consequently, there is a significant variation between MBFs estimated using diastolic or systolic AIF: the use of diastolic AIF yields consistently lower MBF values. When reporting MBF values in the literature, the details of the AIF used for deconvolution should be reported too, to enable direct cross-study comparisons.

Alessia Tognolini¹, Wanda Marfori¹, Cesar Arellano¹, Golnaz Heidari¹, Christine Darwin², Yutaka Natsuaki^1,3, Gerhard Laub^1,3, Mayil Krishnam⁴, and Stefan Ruehm^1
1Diagnostic Cardiovascular Imaging, UCLA, Los Angeles, CA, United States, ²Medicine, Endocrinology, UCLA, Los Angeles, CA, United States, ³Siemens Medical Solution, Los Angeles, CA, United States, ⁴Cardiovascular and Thoracic Imaging, UCI, Irvine, CA, United States

Cardiovascular risk factors can lead to endothelial dysfunction, known precursor of atherosclerosis, which can manifest with impaired arterial vasodilation/paradoxical constriction in response to an appropriate stimulus. Cold pressor test (CPT) can be utilized to assess the endothelium dependent coronary vasomotor function. We utilized 3T cardiac perfusion MRI to detect changes in myocardial signal slope after CPT (immersion of the foot in ice water) in 10 diabetic patients and 10 healthy volunteers. Patients with diabetes showed stable/decreased perfusion after CPT vs. two-fold increase of perfusion in healthy control (p=0.0009). Perfusion MRI with CPT is a promising tool for early imaging of atherosclerosis.

Sotirios Athanasios Tsaftaris^1,2, Richard Tang², Xiangzhi Zhou², Debiao Li², and Rohan Dharmakumar^2
1Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, United States, ²Radiology, Northwestern University, Chicago, IL, United States

Current approaches for analyzing myocardial BOLD changes are suboptimal for detecting critical stenosis. This study proposes, ARREAS (Area-based biomaRker for chaRactErizing coronAry Stenosis), a statistical approach relying on the differences between rest and stress images, to characterize BOLD changes with exquisite sensitivity and specificity. Findings are validated with microsphere perfusion measurements. The method has the potential to rapidly determine the presence of oxygenation anomalies in the myocardium due to coronary artery disease, and provide an unbiased and quantitative imaging biomarker that can enable the assessment of the critical states of stenosis on the basis of BOLD MRI.

Li-Yueh Hsu¹, Peter Kellman¹, Peter Gatehouse², Sven Zuehlsdorff³, Christopher B Glielmi³, and Andrew E Arai^1
1National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States, ²CMR Unit, Royal Brompton Hospital, London, United Kingdom, ³CMR Research and Development, Siemens Medical Solutions, Chicago, IL, United States

While it has been previously shown that myocardial perfusion reserve (MPR) is less sensitive to the nonlinearity of the arterial input function (AIF), using a single-bolus method to quantify myocardial blood flow (MBF) substantially overestimates MBF compared with either dual-bolus or dual-sequence methods.

Octavia Biris^1,2, Neil Chatterjee³, Daniel C Lee^3,4, and James Carr^1,3
1Radiology, Northwestern University, Chicago, IL, United States, ²Biomedical Engineering, Northwestern University, Evanston, IL, United States, ³Feinberg School of Medicine, Northwestern University, Chicago, IL, United States, ⁴Cardiology, Northwestern University, Chicago, IL, United States

Absolute quantification of myocardial perfusion with MRI has the potential to reduce patient mortality from myocardial infarction by detecting coronary stenosis and coronary artery disease in patients with more accuracy than the current state-of-the-art semi-quantitative or qualitative analysis of perfusion images. In order to achieve absolute quantification of myocardial perfusion, we have measured myocardial blood volume and described myocardium-vessel water exchange in an animal model by a new MRI protocol using intra-vascular contrast agent. Myocardial blood volume will be used to calibrate the relative first-pass perfusion images to obtain absolute quantification of myocardial perfusion and cardiac perfusion reserve.

Ting Song^1,2, Maureen N Hood^2,3, Jeffrey A Stainsby⁴, and Vincent B Ho^2,3
1Global Applied Science Laboratory, GE Healthcare, Bethesda, MD, United States, ²Radiology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States, ³Radiology, National Naval Medical Center, Bethesda, MD, United States, ⁴Global Applied Science Laboratory, GE Healthcare, Toronto, ON, Canada

Cardiac perfusion imaging is a recognized method for non-invasive evaluation for myocardial ischemia. There is currently limited report of myocardial perfusion applied in heart failure. In this study of tachycardia-induced heart failure in swine, perfusion shows delayed arrival time, delayed peak time, and reduced slope of enhancement in myocardium.

Heng Ma¹, Lan Ge², Jing An³, David Chen², Lixin Jin⁴, Xiaoming Bi⁵, Renate Jerecic⁴, Kuncheng Li¹, and Debiao Li^2,6
1Xuanwu Hospital, Capital Medical University, Beijing, Beijing, China, People's Republic of, ²Northwestern University, ³Siemens Healthcare, MR Collaboration NE Asia, Siemens Mindit Magnetic Resonance, ⁴Siemens Healthcare, MR Collaboration NE Asia, Siemens Limited China, ⁵Siemens Healthcare, Cardiovascular MR R&D, USA, ⁶Cedars-Sinai Medical Center and UCLA

Conventional myocardial perfusion MRI is limited by the low spatial coverage (3 to 4 slices), temporal and spatial resolution, signal-to-noise ratio, and cardiac motion-related image artifacts. A sliding-window conjugate-gradient HYPR (SW-CG-HYPR) technique allows increased spatial coverage (whole left ventricular coverage), resolution, signal-to-noise ratio and reduced motion artifacts. This work shows that myocardial adenosine stress perfusion MRI with SW-CG-HYPR is feasible and robust in a clinical population. Compared with conventional IR-Turbo-FLASH perfusion MRI, perfusion imaging with SW-CG-HYPR allows whole left ventricular coverage and has higher diagnostic accuracy in patients with suspected CAD.

Elodie Breton^1,2, Daniel Kim¹, Sohae Chung¹, and Leon Axel^1
1Center for Biomedical Imaging - Radiology Research, New York University Langone Medical Center, New York, NY, United States, ²LSIIT - eAVR, University of Strasbourg, Strasbourg, France

Multi-point T1 mapping techniques, such as Modified Look-Locker inversion recovery (MOLLI), have shown quantitative changes in tissue T1 with ischemia but are sensitive to cardiac motion during data acquisition. In this work we developed a pixel-wise myocardial T1-mapping technique with reduced sensitivity to cardiac motion, adapted to perform pre-contrast and delayed-enhancement myocardial T1-mapping, with a 2-heartbeat-long acquisition. The proposed T1-mapping method was compared to a reference multi-point SR fitting method in 8 healthy volunteers before and after a gadolinium contrast injection. It was also performed in 2 patients with arrhythmia but no areas of delayed-enhanced was detected during routine contrast-enhanced clinical exam.