Coronaries & Aorta: Lumen & All
Monday 20 April 2009
Room 313A 11:00-13:00

Moderators:

Matthias Stuber and Qi Yang

 
11:00  22. 3T Contrast-Enhanced Whole Heart Coronary MRA Using 32-Channel Cardiac Coils for the Detection of Coronary Artery Disease
   

Qi Yang11, Kuncheng Li1, Xiaoming Bi2, Jing An3, Feng Huang4, Renate Jerecic2, Debiao Li5
1
Radiology, Xuanwu Hospital, Beijing, China; 2Siemens Medical Solutions; 3Siemens Mindit Magnetic Resonance Ltd; 4Invivo Corporation; 5Northwestern University

    Higher study success rate achieved by 32-channel coils substantially improved overall accuracy of 3T coronary MRA in detecting coronary artery disease when using the intention to diagnose method.
     
11:12 23.

In Vivo Human Coronary Magnetic Resonance Angiography at 7 Tesla

   

Saskia Gerdina Cornelia van Elderen1, Andrew G. Webb1, Maarten J. Versluis1, Jos J.M. Westenberg1, Joost Doornbos11, Nadine B. Smith1, Albert de Roos1, Matthias Stuber2
1
Radiology, Leiden University Medical Centre, Leiden, Netherlands; 22Radiology, Johns Hopkins University Medical School, Baltimore, USA

   

Coronary MRA has been implemented on a 7 tesla human system and tested on eleven volunteers. Adaptations from protocols at lower field strengths include the optimization of navigators, fat suppression and vector ECG placement, as well as volume selective power optimization using a transmit/receive surface coil due to the absence of available body coils at 7 tesla. MRA’s were successfully obtained from all subjects, allowing quantitative measurements of RCA diameter and length, as well as vessel sharpness.

     
11:24 24.

3.0T Whole Heart Coronary MR Angiography Performed as a Part of Comprehensive Contrast Enhanced CMR Study.

   

Motonori Nagata1, Hajime Sakuma1, Nanaka Ishida1, Shingo Kato1, Hiroshi Nakajima2, Masaki Ishida1, Katsuya Onishi2, Masaaki Ito2, Kan Takeda1
1
Radiology, Mie University Hospital, Tsu, Mie, Japan; 2Cardiology, Mie University Hospital, Tsu, Mie, Japan

    Whole heart coronary MRA at 3T was acquired in 52 patients with suspected CAD as apart of comprehensive CMR study. After acquiring perfusion MRI and late gadolinium enhanced MRI, navigator-echo gated, 3D-TFE images were obtained with a patient-specific narrow acquisition window (57.9ms}26.8). Acquisition of MRA was successfully completed in all 52 patients, with averaged imaging time of 11.4 } 4.5 minutes. On a vessel based analysis, the sensitivity, specificity and NPV were 88%, 97% and 97%, respectively. 3.0 T coronary MRA performed as a part of comprehensive cardiac MR study is useful for ruling out significant CAD.
     
11:36  25.

Contrast-Enhanced Whole-Heart Coronary MRA at 1.5T in Less Than 5 Minutes Using Gradient Echo Interleaved EPI and Double Dose of Gd-DTPA

   

Himanshu Bhat1, Sven Zuehlsdorff2, Xiaoming Bi2, Xin Liu1, Renate Jerecic2, Debiao Li1
1
Radiology and Biomedical Engineering, Northwestern University, Chicago, IL, USA; 2Siemens Medical Solutions, Chicago, IL, USA

    A gradient echo interleaved EPI (GRE-EPI) sequence was optimized for contrast-enhanced whole-heart coronary MRA at 1.5T in a scan time less than 5 minutes. This is approximately a factor of 2 reduction in scan time compared to current whole-heart TrueFISP protocols. The reduced scan time made it feasible to acquire images with a more commonly used contrast agent Gd-DTPA instead of high relaxivity contrast agent Gd-BOPTA.
     
11:48  26.

 Are We Reconstructing the Best Images Using Navigator-Gated 3D Coronary MRA?  Multiple-Image Reconstruction Using CLAWS

   

Permi Jhooti1, Jennifer Keegan2, Klaus Scheffler1, David Firmin2
1Radiological Physics, University Hospital Basel, Basel, Switzerland; 2CMR Unit, Royal Brompton Hospital, London, UK

    A technique is presented which acquires a 3D-whole heart scan in the quickest time possible for any respiratory trace (p=ns) and enables 3 images to be reconstructed: the most-frequent 5mm navigator window, an end-expiratory image and an end-inspiratory image. Previous techniques require manual window selections which may not be optimal for scan efficiency or image quality. This modified CLAWS approach enables multiple-image reconstruction in the same acquisition time as for a single image. It is not possible to predict which image will be best. A multi-image technique is therefore optimal, particularly as there is no scan time loss.
     
12:00 27.

Association of Coronary Calcification and Carotid Artery Morphology: A High Resolution Magnetic Resonance Imaging Study

   

qian zhao1, Xihai Zhao2, Feiyu Li2, Qingjun Wang1, Zulong Cai1, Chun Yuan2, Jianming Cai1
1
Department of radiology, PLA General Hospital, Beijing, China; 2Department of radiology, University of Washington, Seattle, WA, USA

    Atherosclerosis has been shown a systematic disease which often involves multiple arterial vascular beds. Recently, a number of studies demonstrated a significant correlation between coronary and carotid atherosclerosis. This study sought to evaluate the association between coronary calcification and carotid artery morphology. The results showed moderate to strong correlation between coronary calcium score detected by CT and carotid morphological measurements by MRI. It indicates that patients with high coronary calcium score may have big plaque burden in carotid arteries. Coronary calcium score as a marker of coronary disease is potentially capable of predicting carotid atherosclerosis.
     
12:12 28.

Multi-Slice Breathhold Phase-Sensitive Coronary Vessel Wall Imaging at 3T

   

Khaled Z. Abd-Elmoniem1, Matthias Stuber1
1
Department of Radiology, Johns Hopkins University, Baltimore, MD, USA

    Black-blood coronary vessel wall imaging is a powerful non-invasive tool for the quantitative assessment of atherosclerotic positive arterial remodeling. Although dual-inversion-recovery (DIR) is the current standard for black-blood coronary vessel wall imaging, optimization of lumen-vessel wall contrast is associated with competing requirements related to TI* (blood signal nulling time), TD (period of minimal myocardial motion), and heart rate. Because of these constraints, the collection of multi slice data during the same cardiac cycle is not easily possible. For these reasons, we have exploited phase-sensitive dual-inversion recovery (PS-DIR) and combined it with a multi-slice spiral signal readout for black-blood coronary vessel wall imaging. Phantom and in vivo data are discussed.
     
12:24 29.

Diagnostic Impact of Aortic MRI at 3Tesla in Acute Stroke Patients

   

Andreas Harloff1, Stefanie Brendecke1, Jan Simon1, Wolf Wallis1, Dawit Assefa2, Thomas Helbing2, Alex Frydrychowicz3, Johannes Weber4, Cornelius Weiller1, Jürgen Hennig3, Michael Markl3
1
Neurology, University Hospital Freiburg, Freiburg, Germany; 2Cardiology and Angiology, University Hospital Freiburg, Freiburg, Germany; 3Diagnostic Radiology, MR Physics, University Hospital Freiburg, Freiburg, Germany; 4Neuroradiology, University Hospital Freiburg, Freiburg, Germany

    The purpose of this study was to evaluate a dedicated multi-contrast 3D MRI protocol for the reliable detection of aortic high-risk plaques in the entire thoracic aorta of acute stroke patients. Findings were compared with transesophageal echocardiography (TEE).
     
12:36 30.   

In Vivo Volumetric MRI in Drug Discovery: A Preclinical Study of the Ezetimibe Therapeutic Efficacy on Atherosclerotic Plaque Burden in the Thoracic Ascending Arterial Tree in ApoE-/- Mice

    Haiying Tang1, Ching H. Chang2, Donna Suresch1, Lesley A. Mcnamara2, Christopher Tong3, Bernd Misselwitz4, Dan Zhou1, Brett M. Connolly1, Jing Xu5, Xun Chen2, Xiaolan Shen6, Chunlian Zhang1, Eric L. Rickes2, Michelle Mariano6, Karim Azer5, Jun Wang2, Cyrille Sur1, Donald S. Williams1, Michael Klimas1, Andrew S. Plump1, Richard Hargreaves1, Haiying Liu1
1
Imaging, Merck Research Laboratories, Rahway, NJ, USA; 2Cadiovascular Disease, Merck Research Laboratories, Rahway, NJ, USA; 3Biometrics, Merck Research Laboratories, Rahway, NJ, USA; 4TRG Diagnostic Imaging, Bayer Schering Pharma AG., Berlin, Germany; 5Applied Computer Science & Math, Merck Research Laboratories, Rahway, NJ, USA; 6LAR, Merck Research Laboratories, Rahway, NJ, USA
    Volumetric MRI of atherosclerotic plaque in the thoracic ascending arterial tree may provide valuable insight into disease progression and therapeutic responses. In this study, in vivo MRI was validated to demonstrate the effectiveness of a potent cholesterol absorption inhibitor, ezetimibe, on the inhibition of the progression of atherosclerosis. Atherosclerotic plaque burden changes in apoE-/- mouse were monitored by longitudinal MRI using a plaque targeting contrast agent Gadofluorine-M. MRI plaque burden quantitation and therapeutic responses were validated by biological approaches. The volumetric data were evaluated to determine the most sensitive biomarker through univariate analysis of plaque volume, area, and thickness measurements.
     
12:48 31.

 Complex Plaques in the Descending Aorta as a Potential Source of Stroke – Visualization of Potential Retrograde Flow Into the Supra-Aortic Arteries Using Multi-Directional 4D Velocity Mapping at 3 Tesla

    Andreas Harloff1, Jan Simon1, stefanie Brendecke1, Wolf Wallis1, Dawit Assefa2, Alex Frydrychowicz3, Johannes Weber4, Jürgen Hennig3, Cornelius Weiller1, Michael Markl3
1
Neurology, University Hospital Freiburg, Freiburg, Germany; 2Cardiology and Angiology, University Hospital Freiburg, Freiburg, Germany; 3Diagnostic Radiology, MR Physics, University Hospital Freiburg, Freiburg, Germany; 4Neuroradiology, University Hospital Freiburg, Freiburg, Germany
    Detection of the precise localization of plaques in the descending aorta using 3D MRI in combination with multi-directional 4D velocity mapping was used to systematically analyze retrograde embolic pathways within the aorta of acute stroke patients. Similar distribution of descending aortic plaque distance and extent of retrograde flow indicate the potential for retrograde embolization in these patients. Particularly, we assessed how frequently the brachiocephalic trunk, the left common carotid and/or subclavian artery were reached by individual flow channels originating directly at the atheroma in the descending aorta.