High‐dose dobutamine stress steady‐state free precession (SSFP) cine MRI at 3T with patient adaptive local radiofrequency (RF) shimming using dual‐source RF transmission. Issue 3 (13th February 2015)

• Record Type: Journal Article
• Authors: Berger, Alexander; Schnackenburg, Bernhard; Schneeweis, Christopher; Kelle, Sebastian; Klein, Christoph; Kouwenhoven, Marc; Fleck, Eckart; Gebker, Rolf
• Is Part Of: Journal of magnetic resonance imaging. Volume 42:Issue 3(2015)
• Page Start: 746
• Page End: 753
• Publication Date: 2015-02-13
• Subjects: Magnetic resonance imaging -- Periodicals; 616
• DOI: 10.1002/jmri.24867
• Languages: English
• ISSNs: 1053-1807

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="jmri24867-sec-0001" sec-type="section"> <title>Purpose</title> <p>To prospectively assess the feasibility, image quality, and diagnostic accuracy of high‐dose dobutamine stress magnetic resonance imaging (DSMR) using steady‐state free precession (SSFP) cine imaging at 3T applying a dual‐source radiofrequency (RF) excitation magnetic resonance imaging (MRI) system with parallel transmission and patient adaptive local RF shimming.</p> </sec> <sec id="jmri24867-sec-0002" sec-type="section"> <title>Materials and Methods</title> <p>DSMR using SSFP cine imaging was performed in 44 patients at 3T scheduled for a clinically indicated coronary angiography. The effect of conventional versus dual‐source RF transmission was assessed regarding homogeneity of the B<sub>1</sub> field, contrast‐to‐noise ratios (CNRs) at rest, image quality, and diagnostic accuracy of DSMR using long and short axis.</p> </sec> <sec id="jmri24867-sec-0003" sec-type="section"> <title>Results</title> <p>The mean percentage of the intended flip angle within the heart increased from 88 ± 9.1% with single‐source to 103 ± 5.6% (<italic>P</italic> < 0.001) dual‐source RF transmission. CNR increased for dual‐source particularly at the apex (63.4 ± 24.2 vs. 36.5 ± 16.5, <italic>P</italic> < 0.001) but also at the base of the left ventricle (LV) (50.1 ± 14.8 vs. 39.3 ± 15.8, <italic>P</italic> < 0.001). Image quality of dual‐source was higher both at rest (2.8 ± 0.5 vs. 2.6 ± 0.7, <italic>P</italic> < 0.001) and stress (2.5 ± 0.7 vs. 2.0 ± 1.0, <italic>P</italic> < 0.001). The number of segments with severe artifacts or nondiagnostic image quality at stress was lower with dual‐source RF transmission (8% vs. 27%, <italic>P</italic> < 0.001). The diagnostic accuracy of DSMR in coronary territories using dual‐source RF transmission was significantly higher (77% vs. 65%, <italic>P</italic> = 0.04).</p> </sec> <sec id="jmri24867-sec-0004" sec-type="section"> <title>Conclusion</title> <p>Patient adaptive local RF shimming using dual‐source RF transmission provided significantly improved image quality and higher diagnostic accuracy of SSFP during DSMR at 3T compared to conventional RF transmission. J. Magn. Reson. Imaging 2015;42:746–753.</p> </sec> </abstract>