Myocardial Function: Technical Developments

Tuesday 13 May 2014

Kestutis J. Barkauskas¹, Jesse I. Hamilton¹, Yong Chen¹, Dan Ma¹, Katherine L. Wright¹, Wei-Ching Lo¹, Prabhakar Rajiah², Vikas Gulani², Mark A. Griswold², and Nicole Seiberlich^1
1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, ²Radiology, University Hospitals, Cleveland, OH, United States

The feasibility of volumetric coverage of the left ventricle within a single breathhold at isotropic reconstructed resolution for cardiac MR functional imaging was explored. The 3D Stack-of-Spirals trajectory and 3D through-time non-Cartesian GRAPPA reconstruction were combined to yield volumetric cine scans with spatial resolution of 2.47mm³ and temporal resolution of 32ms. Total 3D scan time was nearly 4-fold shorter than when acquiring the clinical standard 2D short-axis functional scan. These 4D images could be reformatted to arbitrary imaging planes without prior image registration, demonstrating the potential assessment of valve patency or the entire length of the papillary muscle anatomy.

Sebastian Littin¹, Maxim Zaitsev¹, Waltraud Brigitte Buchenberg¹, Anna Masako Welz¹, Hans Weber¹, Feng Jia¹, Frederik Testud¹, Daniel Gallichan², Jürgen Hennig¹, and Walter R. T. Witschey^3
1Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany, ²EPFL Lausanne, Switzerland, ³Department of Radiology, University of Pennsylvania, Pennsylvania, United States

Here we present a method for field-of-view reduction in cardiac CINE-MRI. A nonlinear prephasing gradient generated by a high-performance monoplaner gradient system is used for signal spoiling along phase-encoding direction. A speed up of 60% without additional SAR is demonstrated in a clinically relevant application.

Jing Liu¹, Li Feng², and David Saloner^1
1University of California San Francisco, San Francisco, CA, United States, ²New York University, NY, United States

An effective k-space undersampling scheme (CIRCUS) for 3D Cartesian imaging with compressed sensing and parallel imaging has successfully been implemented and applied to free-breathing 4D cardiac imaging. Our preliminary results demonstrated the nice features and great potentials of the proposed acceleration method. We showed promising whole heart CINE images achieved in 2 minute scan time.

Simone Coppo^1,2, Davide Piccini^3,4, Gabriele Bonanno^1,2, Jerome Chaptinel^1,2, Gabriella Vincenti⁵, and Matthias Stuber^1,2
1Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, ²Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, ³Advanced Clinical Imaging Technology, Siemens Healthcare IM BM PI, Lausanne, Switzerland, ⁴Radiology, University Hospital (CHUV) and University of Lausanne (UNIL)/ Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, ⁵Division of Cardiology and Cardiac MR Center, University Hospital (CHUV), Lausanne, Switzerland

A novel self-navigated 3D radial whole-heart cine sequence for combined coronary anatomy visualization and ventricular function assessment is introduced. The sequence is not ECG-triggered and allows for the retrospective selection of both the acquisition window duration and its relative position in the cardiac cycle. In addition, multiplanar reformatting at any user-defined anatomical level is enabled for these 3D cine datasets. First combined coronary MRA and ventricular function data obtained with this approach in vivo and in humans are presented.

Aurelien F. Stalder¹, Peter Speier¹, Michael Zenge¹, Andreas Greiser¹, Christoph Tillmanns², and Michaela Schmidt^1
1Siemens AG Healthcare Sector, Erlangen, Germany, ²Diagnostikum Berlin, Berlin, Germany

CINE and delayed enhancement imaging are widely used in cardiac MRI to evaluate function and viability, respectively. In this work, we demonstrate a new technique to acquire both function and viability in a short breath-hold of 4 seconds. The technique is based on highly-accelerated IR real-time CINE 2D bSSFP using compressed sensing to produce images with high spatial and temporal resolution. Subsequently, a registration and motion-propagation strategy is used to reconstruct CINE series for each of the acquired TI-contrasts. Based on multi-TI CINE series, it is possible to retrospectively visualize any TI-contrast as CINE or to reconstruct CINE pseudo-T1 maps.

Yu Li¹, Janaka Wansapura¹, Hui Wang², Jean Tkach¹, Michael Taylor³, and Charles Dumoulin^1
1Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, ²MR Clinical Science North America, Philips HealthCare, Cleveland, OH, United States, ³Cardiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States

We investigated a new cardiac imaging technique that uses k-t parallel imaging reconstruction in an undersampled wavelet-space for real-time free-breathing data acquisition. This technique decomposes the original cardiac data into a series of multi-scale k-t data with a small frequency bandwidth using real-time wavelet decomposition filters. The bandwidth reduction allows for the use of neighboring time frames in wavelet-space k-t reconstruction, providing an approach to improving SNR without a considerable loss of dynamic information. The feasibility of this approach is demonstrated.

Friedrich Wetterling^1,2
1Faculty of Engineering, Trinity College, the University of Dublin, Dublin, Leinster, Ireland, ²Tomometrics Ltd., Dublin, Leinster, Ireland

Standard MRI 300MHz loop resonators when placed on a human chest can serve to record variations related to the cardiac cycle with no influence of respiration on a network analyser. Radio-frequeny cardiography (rf CG) signals have been correlated with electrocardiographic (ECG) measurements and one rf-CG sensor was used to record a cardiac MR image at 7T. This technique proises to work well during free breathing and requires no tissue contact. The recorded variations may have to be considered for fine adjustment of feeding current phase shifts between multiple transmit resonators during B1-shimming. The results indicate that double-tuned resonators could serve as a unique sensor for rf-CG and detection of the MR signal for cardiac MRI.

Francisco Contijoch¹, Walter RT Witschey¹, Jeremy McGarvey¹, Madonna Lee¹, Norihiro Kondo¹, Toru Shimaoka¹, Chikashi Aoki¹, Satoshi Takebayashi¹, Gerald A Zsido¹, Christen Dillard¹, Joseph H Gorman¹, Robert C Gorman¹, and James J Pilla^1
1University of Pennsylvania, Philadelphia, PA, United States

Current imaging methods provide non-invasive and high spatial resolution approach, but are load-dependent since values obtained are influenced by the end-diastolic volume (preload) and arterial impedance (afterload). In this work, we developed an MRI method to quantify regional response to alterations in preload. As a result, we obtain regional Frank-Starling relations in infarcted swine.

Guido Buonincontri¹, Carmen Methner², Thomas Krieg², T Adrian Carpenter¹, and Stephen J Sawiak^1,3
1Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom, ²Department of Medicine, University of Cambridge, Cambridge, United Kingdom, ³Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom

Long scan duration limits the usage of cine MRI methods in mice. We employed spatiotemporal compressed sensing and parallel imaging to accelerate retrospectively-gated cine MRI of mouse hearts. We found that the scan time for the whole heart could be reduced to one minute when using radial sampling. The accuracy in the estimation of left and right ventricular volumes was preserved for all tested subjects. This method can be used to perform fast and accurate functional MRI exams in mice.

Ana Resetar¹, Stefan H. Hoffmann¹, Andreas Graessel², Helmar Waiczies³, Thoralf Niendorf^2,4, and Armin M. Nagel^1
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, ²Berlin Ultrahigh Field Facility, Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany, ³MRI.TOOLS GmbH, Berlin, Germany, ⁴Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Berlin, Germany

A retrospectively gated reconstruction routine for ²³Na-MRI of the human heart using a density-adapted 3D projection reconstruction sequence with standard and golden angle sampling scheme is presented. Different heart phases with temporal resolutions of 0.2s (5 phases) and 0.1s (10 phases) were reconstructed by filling the k-spaces retrospectively according to an acoustic trigger signal. Golden angle sampling yields a more homogeneous distribution of projections which results in reduced image artefacts and higher SNR.