Center for MR Research, University of Illinois Medical Center, Chicago, Illinois 60612, USA.
Magn Reson Med. 2011 Dec;66(6):1582-9. doi: 10.1002/mrm.22953. Epub 2011 May 31.
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.
虽然在治疗前列腺癌的冷冻手术期间需要进行温度测绘，但仍需要一种有效的方法来实现这一目标。我们在体内犬类实验和冷冻组织的离体组织样本实验中都已经证明了相位偏移与温度之间的关系。该相位偏移的幅度要大得多（在 0.5 T 时，回波时间为 0.1 ms 时，约为 0.7°C/°C），比传统的质子共振频率偏移（0.008°C/°C）预测的幅度大得多。它几乎不依赖于所使用的回波时间，因此不是由于频率变化引起的，尽管在冷冻组织附近已经观察到了频率相关的相位偏移。该相位偏移在冷冻组织内随温度单调变化，因此可能可用于冷冻消融应用中的新型温度测绘方法。
