LETTER TO THE EDITOR
Magnetic resonance to assess the aortic valve area in aortic stenosis
Matthias Friedrich, MD, FESC
Franz-Volhard-Klinik, Charité Campus Berlin-Buch, Department of Cardiology, Humboldt University Berlin, Wiltbergstr. 50, 13125 Berlin, Germany
Jeanette Schulz-Menger, MD and
Rainer Dietz, MD
friedrich{at}fvk-berlin.de
The study by John et al. (1) describes the results of a comparative study using cardiovascular magnetic resonance (CMR) to measure aortic valve area in patients with aortic valve stenosis. It is important to emphasize the potential of this technique to perform a planimetric quantification of the stenosis. But in order to avoid disappointing results by future applicants of that approach, it should be added that the technique used in this study is not state-of-the-art. The sequence used (flash two-dimensional cine gradient echo) uses an echo time of 4.8 ms and thus is very likely to suffer from so-called spin-dephasing artifacts which display the transstenotic jet as a (gray to black) signal void. This makes it difficult to reliably measure the area as reported by the authors. If others are willing to apply CMR to measure valve area, they should make use of steady-state-free-precession (SSFP) sequences with much shorter echo times and thus more easily identifiable orifices. The use of the standard SSFP sequence is much less susceptible to this problem (2). In a recent study, we have shown that using this state-of-the-art technique, CMR yields reliable results (3). In preparing this study, we have compared both techniques and experienced a limited accuracy of the technique used by John et al. when compared with the SSFP-based approach.
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References
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- John AS, Dill T, Brandt RR, et al. Magnetic resonance to assess the aortic valve area in aortic stenosis: how does it compare to current diagnostic standards? J Am Coll Cardiol. 2003;42:519–526[Abstract/Free Full Text]
- Hildebrand LB, Buonocore MH. Fully refocused gradient recalled echo (FRGRE): factors affecting flow and motion sensitivity in cardiac MRI. J Cardiovasc Magn Reson. 2002;4:211–222[CrossRef][Medline]
- Friedrich MG, Schulz-Menger J, Poetsch T, Pilz B, Uhlich F, Dietz R. Quantification of valvular aortic stenosis by magnetic resonance imaging. Am Heart J. 2002;144:329–334[CrossRef][Medline]
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