Boosting 19F MRI—SNR efficient detection of paramagnetic contrast agents using ultrafast sequences |
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Authors: | Florian Schmid Carsten Höltke David Parker Cornelius Faber |
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Affiliation: | 1. Department of Clinical Radiology, University Hospital Münster, , Münster, Germany;2. Department of Chemistry, Durham University, , Durham, United Kingdom |
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Abstract: | 19F MRI offers high specificity but usually low sensitivity. Here, paramagnetic relaxation enhancement is assessed as a method to improve SNR efficiency in 19F MRI. Compounds with short relaxation times are used that combine fluorine and a paramagnetic ion within the same molecule. Different molecular designs provide T1 values in the range of 1.4–15 ms and /T1 ratios from 0.3 to 1. Gradient echo, as well as ultrafast radial MR sequences, is optimized to achieve highest SNR efficiency. Compared to nonparamagnetic compounds, ultrafast sequences can yield a gain of up to a factor 27 in sensitivity, whereas the gain with gradient echo is only factor 11. Comparison among the paramagnetic compounds shows that /T1 close to unity is a prerequisite for highest SNR efficiency gain and that best results are obtained for compounds with T1 in the range of 1–5 ms. Magn Reson Med 69:1056–1062, 2013. © 2012 Wiley Periodicals, Inc. |
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Keywords: | 19F MRI SNR efficiency ultrashort echo time imaging zero echo time paramagnetic relaxation enhancement |
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