科研之友
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摘要
Purpose: To provide quantitative temperature monitoring for thermal therapies in bone marrow by measuring temperature-dependent signal changes in the bone marrow of ex vivo canine femurs heated with a 980-nm laser at 1.5T and 3.0T.
Materials and Methods: Using a multi-gradient echo (<= 16) acquisition and signal modeling with the Stieglitz-McBride algorithm, the temperature sensitivity coefficients (TSC, ppm/degrees C) of water and multiple lipid components' proton resonance frequency (PRF) values are measured at high spatiotemporal resolutions (1.6 x 1.6 x 4 mm(3), <= 5 seconds). Responses in R(2)* and amplitudes of each peak were also measured as a function of temperature simultaneously.
Results: Calibrations demonstrate that lipid signal may be used to compensate for B(0) errors to provide accurate temperature readings (< 1.0 degrees C). Over a temperature range of 17.2-57.2 degrees C, the TSCs after correction to a bulk methylene reference are -0.87 x 10(-2) +/- 4.7 x 10(-4) ppm/degrees C and -0.87 x 10(-2) +/- 4.0 x 10(-4) ppm/degrees C for 1.5T and 3.0T, respectively.
Conclusion: Overall, we demonstrate that accurate and precise temperature measurements can be made in bone marrow. In addition, the relationship of R2* and signal amplitudes with respect to temperature are shown to differ significantly where conformal changes are predicted by Arrhenius rate model analysis.
- 出版日期2011-5
