Cardiac function and myocardial strain analysis at 7T using B1 shimming in comparison to 3T magnetic resonance imaging

Figures

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  Fig. 1. Estimated B1 + magnitude at 7T for a subject for the different B1 + shim settings, calculated on the ROI comprising three slices covering the heart. Note the strongly reduced CV for the homogenous shim solution in comparison to the efficient shim solution, which is still affected by pronounced signal dropouts within the ROI (see arrows)

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  Fig. 2. A representative example of a subject showing diastolic and systolic images acquired with a low (standard) resolution at 3T (bSSFP) and 7T (spoiled GRE): upper to lower row: 4-, 2-, 3-chamber, short-axis views. Note the bSSFP related flow artifacts, particularly in the systole (arrows)

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  Fig. 3. 7T (left) and 3T (right) images in 4-chamber (upper) and short-axis (lower) views demonstrating a better visibility of myocardial structures for high spatial resolution compared to the lower resolution images

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  Fig. 4. Short-axis (a) and 4-chamber (b) views demonstrating bSSFP related banding artifacts acquired at 3T with the corresponding 7T images; \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\:{B}_{1}^{+}$$\end{document} related signal shading at 7T (including the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\:{B}_{1}^{+}$$\end{document} map) and its corresponding 3T image (c). Note that the slice locations of 3T and 7T images do not necessarily match

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  Fig. 5. Image grading for all data sets for short-axis (left panel) and long-axis (right panel) cine images, displayed as diverging bars with proportions of the Likert scale vales. *denotes significant differences (p < 0.05)

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  Fig. 6. Image grading for the two readers for all grading categories, each separately for long-axis (LA) and short-axis (SA). *denotes significant differences (p < 0.05)