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Ramkumar Krishnamurthy¹, ², Benjamin Y. Cheong², ³, Raja Muthupillai², ³

¹Rice University, Houston, Texas, USA; ²St. Luke's Episcopal Hospital, Houston, Texas, USA; ³Baylor College of Medicine, Houston, Texas, USA

We describe a navigator-guided free breathing (Nav-SSFP), and a SENSE accelerated (Sen-SSFP) breath-held steady-state free precession (SSFP) cine imaging techniques that provide high temporal resolution (3-6 ms).  We demonstrate that images acquired using these techniques can be used to measure various indices such as isovolumic relaxation time, time-to-peak filling rate, time-to-peak ejection rate, etc., for characterizing diastolic function as well as myocardial dyssynchrony.  The results from our investigation in 10 normal subjects demonstrate that both techniques yield comparable metrics for quantifying diastolic function.

VIvek Muthurangu¹, Andrew Taylor¹, Philip Lurz¹, Michael Hansen¹

¹UCL Institute of Child Health, London, UK

Study to assess the accuracy of ventricular volumes measured using high spatio-temporal resolution radial real-time imaging accelerated with kt-sense in patients with congenital heart disease. Compared to standard real-time imaging radial kt-SENSE images were of high quality. In addition, using cardiac gated imaging as a reference standard method, radial kt-SENSE was more accurate than standard real-time assessment of cardiac function. This technique offers the possibility of accurate real-time assessment of cardiac function. This may be particularly useful in patients who find breath holding difficult (i.e. children), and patients with irregular heart rhythms.

Corinna S. Maier¹, ², Michael Bock², Wolfhard Semmler², Christine H. Lorenz³

¹Siemens Corporate Research, Princeton, New Jersey, USA; ²German Cancer Research Center (dkfz), Heidelberg, Germany; ³Siemens Corporate Research, Baltimore, Maryland, USA

Monitoring the ECG for ischemic changes during dobutamine stress testing or MR-guided interventions is not possible in the MR environment due to the magnetohydrodynamic effect. A real time MR was converted to an m-mode (motion mode) representation analogous to echocardiography for simple continuous display of cardiac function. An active contours segmentation algorithm was developed to detecte the myocardial borders to enable the calculation of regional wall thickening. Preliminary results show that the method may allow semi-automated change detection as a monitoring method for CMR.

Peter Kellman¹, Christophe Chefd'hotel², Christine H. Lorenz³, Christine Mancini¹, Andrew E. Arai¹, Elliot R. McVeigh⁴

¹NIH, Bethesda, Maryland, USA; ²Siemens Corporate Research, Princeton, New Jersey, USA; ³Siemens Corporate Research, Baltimore, Maryland, USA; ⁴Johns Hopkins University, Baltimore, Maryland, USA

Real-time cardiac cine imaging typically has compromised image quality compared with gated, segmented breath-held studies. The proposed approach produces high quality cine images with high spatial and temporal resolution matching that of conventional segmented cine using fully automated retrospective reconstruction with real-time acquired image data.

Alan M. Groves¹, David J. Larkman¹, Stephen T. Goldring¹, Giuliana Durighel¹, Julie A. Fitzpatrick¹, Jo V. Hajnal¹, A David Edwards¹

¹Hammersmith Hospital, Imperial College London, London, UK

Cardiac MR has demonstrated the presence of intra-atrial vortices in the adult heart which are thought to conserve the momentum of inflowing blood during atrial filling. Circulatory changes around the time of birth have potential to disrupt these vortices. In this work preliminary assessment of intracardiac flow in newborn preterm and term infants with phase contrast imaging is described, along with vector map visualisation of intra-atrial flow patterns. The potential mechanism and significance of this deviation from the adult pattern is discussed.

Ludovic de Rochefort¹, Thanh Nguyen¹, Ryan Brown¹, Martin R. Prince¹, Yi Wang¹

¹Weill Medical College of Cornell University, New York, New York, USA

Paramagnetic contrast agents (CA) modify tissue susceptibility and distort magnetic fields in proportion to their concentration. The frequency shift is proportionnal to the contrast agent concentration and a shape factor which can be calculated provided that the shape is known. Here, using an inversion method, [CA] was measured continuously in the aortic arch during the first-pass MRA. Cardiac output was measured and compared to phase-contrast data evaluating the ability of the method to quantify susceptibility in vivo and derive physiological parameters.

Ewart Mark Haacke¹, ², Jaladhar Neelavalli¹, Samuel Barnes¹, Zahid Latif¹

¹Wayne State University, Detroit, USA

The risk for deep vein thrombosis (DVT) increases with age and for travellers who are immobile for more than 4 hrs. In this abstract, using ssusceptibility weighted imaging, we show some evidence that points to the transient settling of blood as a possible cause of DVT.

Peter Kellman¹, Diego Hernando², Saurabh Shah³, Sven Zuehlsdorff³, Renate Jerecic³, Christine Mancini¹, Zhi-Pei Liang², Andrew E. Arai¹

¹NIH, Bethesda, Maryland, USA; ²University of Illinois, Urbana, Illinois, USA; ³Siemens Medical Solutions, Chicago, Illinois, USA

A Multi-echo Dixon fat and water separation method for detecting fibro-fatty infiltration in the myocardium can be used before or after contrast administration. The method is easy to use and provides improved contrast compared with conventional fat suppression.

Alexander Karaus¹, Dietmar Merboldt¹, Joachim Graessner², Jens Frahm¹

¹Biomedizinische NMR Forschungs GmbH am MPI fuer biophysikalische Chemie, Goettingen, Germany; ²Siemens Medical Solutions, Hamburg, Germany

Because stimulated echoes dephase signals from moving spins, high-speed STEAM MRI sequences were developed for "black-blood" imaging of the heart that overcome limitations of double inversion-recovery techniques. Multislice images along anatomic orientations and triggered to end diastole were obtained from healthy subjects at 3 T. Optimum SNR and resolution of typically 2.0 × 2.0 mm2 (6 mm section thickness) were achieved by segmented multi-shot sequences with interleaved k-space acquisitions (160 ms each) from several heart beats during a single breathhold. Rapid STEAM MRI emerges as a simple technique for multislice imaging of the myocardial wall with efficient flow suppression.

Zhaoyang Fan¹, ², Zhuoli Zhang¹, Yiucho Chung³, Peter Weale³, John Sheehan¹, Natasha Berg¹, Ioannis Koktzoglou¹, Mark Morasch¹, Timothy Carroll¹, ², Renate Jerecic³, James Carr¹, Debiao Li¹, ²

¹Northwestern University, Chicago, Illinois, USA; ²Evanston, Illinois, USA; ³Siemens Medical Solutions, Chicago, Illinois, USA

3D MRI offers advantages over 2D techniques for vessel wall visualization, but blood suppression and imaging time are more challenging. A motion-sensitized dephasing (MSD) preparation was combined with a fast 3D TSE sequence (SPACE), and residual intraluminal blood was suppressed dramatically at 3.0T. It was demonstrated on healthy volunteers and carotid atherosclearotic patients that MSD-SPACE is capable of achieving a superior spatial resolution (0.63 mm isotropic), shorter scan time, and significantly higher wall-lumen CNR efficiency as compared to multi-slice 2D TSE using inflow/outflow saturation band technique. MSD-SPACE is a promising technique for plaque screening in the carotid arteries at 3.0T.