| Autor: |
Maat, G. H., Leeuw, H., Seevinck, P. R., Bosch, M. A. A. J., Nijsen, J. F. W., Bakker, C. J. G. |
| Zdroj: |
Magnetic Resonance in Medicine; Jan2015, Vol. 73 Issue 1, p273-283, 11p |
| Abstrakt: |
Purpose To present a new method, S0 estimation of the free induction decay combined with a single spin echo measurement (SOFIDSE), that enables simultaneous measurements of R2*, R2, and R2′ in order to quantify the local concentration of holmium microspheres (Ho-MS) for radioembolization. Theory and Methods SOFIDSE estimates R2* and the signal magnitude at time point 0, S0, from a multigradient echo readout of the free induction decay and subsequently estimates R2 using S0 and a single spin echo, from which R2′ is deducted. The method was evaluated by comparing SOFIDSE R2 values with values obtained from shifted spin echo (SSE) measurements on a phantom setup containing Ho-MS and from dual spin echo measurements on a healthy volunteer. Results On average, SOFIDSE showed a small overestimation of R2 values compared with SSE independent of the microsphere concentration. R2′ values determined by subtraction of either SOFIDSE R2 or SSE R2 from R2* showed excellent agreement (correlation coefficient = 1; P = 9 · 10−11). The Ho-MS-induced R2′ values obtained by SOFIDSE were insensitive to the R2 value of the tissue in which they resided. Conclusion SOFIDSE enables quantification of Ho-MS, in media with spatially or temporally varying R2 values, in a single acquisition. Magn Reson Med 73:273-283, 2015. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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