ISMRM 21st Annual Meeting & Exhibition 20-26 April 2013 Salt Lake City, Utah, USA

Myocardial Perfusion: Technical Development & Clinical Needs
Tuesday 23 April 2013
Room 150 AG  16:00 - 18:00 Moderators: Christopher J. P. François, Michael Jerosch-Herold

16:00 0315.   Introduction
Amit R. Patel
16:12 0316.   Quantitative Spiral Perfusion Imaging: Initial Clinical Experience
Michael Salerno1,2, Yang Yang3, Sujith Kuruvilla1, Craig H. Meyer3, and Christopher M. Kramer1,2
1Medicine, Cardiology, University of Virginia, Charlottesville, VA, United States, 2Department of Radiology, University of Virginia, Charlottesville, VA, United States,3Biomedical Engineering, University of Virginia, Charlottesville, VA, United States

We present our initial clinical experience using a newly developed quantitative spiral perfusion pulse sequence for adenosine stress CMR in patients with coronary artery disease. High resolution perfusion images and pixel-wise maps of absolute myocardial perfusion can be obtained with this pulse sequence without any time penalty during data acquisition. In normal subjects the resting perfusion is near 1mL/g/min as expected. In two patients who underwent cardiac catheterization there was excellent correlation between regions of reduced stress perfusion and obstructive coronary artery disease..

16:24 0317.   Myocardial Perfusion Assessment in Humans Using Steady-Pulsed Arterial Spin Labeling
Thibaut Capron1, Thomas Troalen1, Benjamin Robert2, Alexis Jacquier1, Patrick J. Cozzone1, Monique Bernard1, and Frank Kober1
1Centre de Résonance Magnétique Biologique et Médicale CRMBM UMR CNRS 7339, Aix-Marseille Université, Marseille, France, 2Siemens Healthcare, Saint-Denis, France

We propose a steady-pulsed labeling approach for improving sensitivity of myocardial perfusion ASL in humans based on a technique recently validated in mice. Blood was labeled in the aorta at a specific timepoint in the cardiac cycle in a series of SSFP single-shot images. The sequence was tested on nine volunteers under free breathing and compared with a FAIR-SSFP breath-hold technique. The ASL signal was found to be higher with the new technique than with FAIR. Myocardial blood flow values were found in agreement with previously reported studies. This method appears particularly interesting for studying pathologies with diffuse microvascular alterations.

16:36 0318.   Use of Deformable Registration for Quantification of Cardiac Perfusion in Patients with Arrhythmia
Devavrat Likhite1, Ganesh Adluru1, Christopher J. McGann2, and Edward V.R. DiBella1
1UCAIR/Radiology, University of Utah, Salt Lake City, Utah, United States, 2Cardiology, University of Utah, Salt Lake City, Utah, United States

Dynamic contrast enhanced MRI is maturing as a tool in contemporary cardiovascular medicine and quantifying cardiac perfusion is becoming clinically relevant. However, the use of ECG gating is a problem under certain conditions and can challenge current quantification methods. Here we use self-gated approach, which increases the processing complications as it requires additional steps to correct for cardiac motion present. This work presents the use of deformable registration that improves the accuracy quantification of cardiac perfusion .The quantification results obtained from the registered ungated acquisitions show good correlation with those from gated acquisitions.

16:48 0319.   Rapid Ungated CMR Perfusion Imaging to Evaluate Coronary Artery Disease in Patients with Arrhythmia
Krishna N. Velagapudi1,2, Alexis Harrison1,2, Ganesh Adluru3,4, Akram Shaaban4, Brent Wilson1,2, Daniel Kim2,3, Nassir F. Marrouche1,2, Christopher J. McGann1,2, and Edward V.R. DiBella2,3
1Division of Cardiology, University of Utah, Salt Lake City, Utah, United States, 2CARMA, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, United States, 3Utah Center for Advanced Imaging Research, Department of Radiology, University of Utah, Salt Lake City, Utah, United States, 4Department of Radiology, University of Utah, Salt Lake City, Utah, United States

Cardiac Magnetic Resonance (CMR) perfusion imaging is an emerging noninvasive tool for evaluating coronary artery disease in intermediate risk patients. Its utility may be limited in patients with arrhythmia and gating problems during the scan, which degrade image quality and may preclude accurate interpretation. This study performs an initial evaluation of the quality of images and the diagnostic utility of ungated and self-gated perfusion CMR in evaluating coronary disease in eight patients, including patients with arrhythmia.

17:00 0320.   First-Pass Contrast-Enhanced Cardiac Perfusion with 3D Coverage Per Heartbeat with 3D Through-Time Radial GRAPPA
Kestutis Barkauskas1, Jesse Hamilton1, Bruce S. Spottiswoode2, Sven Zuehlsdorff2, Mark A. Griswold1,3, and Nicole Seiberlich1
1Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States, 2Cardiovascular MR R&D, Siemens Medical Solutions, Chicago, Illinois, United States, 3Radiology, Case Western Reserve University, Cleveland, Ohio, United States

The objective was to provide whole-heart coverage within diastole of each cardiac cycle during a first-pass contrast-enhanced cardiac perfusion study. An ECG-gated, 3D Radial FLASH sequence with a stack-of-stars trajectory required 341ms per volume by undersampling the angular and partition directions. Cartesian GRAPPA in the partition direction followed by 3D Through-time Radial GRAPPA in the angular direction reconstructed the data. Despite net 16-fold acceleration with respect to a Cartesian trajectory, partition alias was not observed and myocardial uptake followed expected dynamics. These results suggest that 3D Through-time Radial GRAPPA may be a viable option for obtaining clinically relevant cardiac perfusion estimates.

17:12 0321.   A Comparison of Myocardial Signal Intensity Correction Methods in First-Pass Perfusion MRI
Jacob Fluckiger1 and Daniel Lee1
1Northwestern University, Chicago, IL, United States

Three different methods for correcting myocardial signal saturation in first pass perfusion MRI are tested in canine models of coronary artery disease. Following signal correction, myocardial blood flow is quantified and results are compared with microsphere flow. Using a contrast agent dose of 0.05 mmol/kg, uncorrected myocardial signal time courses underestimated flow values by 10% or more when the microsphere flow was greater than 4 ml/min/gm. Two of the three correction methods tested returned flow values that were not significantly different from microsphere flow.

17:24 0322.   Subcellular Distribution of Manganese and Its Impact on Mitochondrial Function in Rat Cardiac Myocytes
Ya Chen1, Mariana G. Rosca2, Charles L. Hoppel2,3, and Xin Yu1
1Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2School of Medicine, Case Western Reserve University, Cleveland, OH, United States, 3Department of Pharmacology, Case Western Reserve University, Cleveland, OH, United States

This study aims to elucidate the mechanisms leading to long Mn2+ retention in cardiac myocytes. Subcellular distribution of Mn2+ was delineated by ICP-OES. The impact of Mn2+ accumulation on mitochondrial respiration was also assessed by isolated mitochondrial studies.

17:36 0323.   Feasibility of Cyclic Myocardial Perfusion Variation Assessment During Adenosine-Induced Stress in Rats
Thomas Troalen1, Thibaut Capron1, Monique Bernard2, Patrick J. Cozzone2, and Frank Kober1
1Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR CNRS N°7339, Faculté de Médecine, Aix-Marseille Université, Marseille, France, 2Centre de Résonance Magnétique Biologique et Médicale (CRMBM), Aix-Marseille Université, Marseille, France

This study presents the use of a recently proposed arterial spin labeling method for assessing cyclic variations of myocardial blood flow (MBF) in small rodents. An ECG-gated steady-pulsed labeling approach was combined with simultaneous readout over the cardiac cycle using cine-FLASH to obtain cyclic temporally resolved MBF maps across the cardiac cycle with 6 ms resolution. The new protocol was carried out on one Wistar rat at rest and during intravenous adenosine-induced stress. Perfusion was found higher during stress, but the relative variation was slightly lower compared to rest.

17:48 0324.   First-Pass MRI Detects Reduced Myocardial Perfusion Reserve in ApoE-/- Mice on a High-Cholesterol Diet
Nivedita K. Naresh1, Xiao Chen1, Patrick F. Antkowiak1, Rene J. Roy2, and Frederick H. Epstein1,3
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, 2School of Medicine, University of Virginia, Charlottesville, VA, United States,3Radiology, University of Virginia, Charlottesville, VA, United States

Atherosclerosis and the associated cardiovascular diseases remain the largest cause of morbidity and mortality in the western world. We developed a compressed sensing (CS)-accelerated first pass sequence for mice with a dual-contrast acquisition and using ApoE-/- mice on high cholesterol diet, we sought to establish a mouse model of coronary vascular dysfunction, documented by reduced myocardial perfusion reserve. Perfusion reserve was reduced in ApoE-/- mice fed a high cholesterol diet for 12 weeks as compared to wild type mice. These methods will enable us to investigate molecular mechanisms that underlie the link between high cholesterol and abnormal coronary vascular function.