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MRI of frozen tissue demonstrates a phase shift
Author(s) -
Lu Aiming,
Daniel Bruce L.,
Kaye Elena,
Butts Pauly Kim
Publication year - 2011
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.22953
Subject(s) - phase (matter) , cryosurgery , nuclear magnetic resonance , cryoablation , frequency shift , materials science , echo (communications protocol) , in vivo , chemistry , optics , physics , computer science , radiology , medicine , biology , ablation , computer network , microbiology and biotechnology , organic chemistry
While temperature mapping is desired during cryosurgery for prostate cancer treatment, an effective approach for this purpose is still needed. We have demonstrated a phase shift with temperature in our in vivo canine experiments and ex vivo tissue sample experiments within the frozen tissue. The phase shift is much larger (∼0.7 °/°C with an echo time of 0.1 ms at 0.5 T) in magnitude than that predicted by conventional proton resonant frequency shift (0.008 °/°C). It shows little dependence on the echo times used and thus is not due to a frequency change, although frequency‐dependent phase shift has been observed near the frozen tissue. This phase shift varies monotonically with temperature within the frozen tissue and therefore may be potentially used as a novel temperature mapping approach in cryoablation applications. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.