Karakitsios Ioannis, Bobeica Mariana, Saliev Timur, Rube Martin, Melzer Andreas
Institute for Medical Science and Technology (IMSaT), University of Dundee , Dundee , United Kingdom.
Minim Invasive Ther Allied Technol. 2014 Mar;23(2):120-6. doi: 10.3109/13645706.2013.839950. Epub 2013 Sep 30.
The purpose of this work was to determine the accuracy of Proton Resonance Frequency (PRF) thermometry during MR-guided Focused Ultrasound (MRgFUS) ablation on explanted Thiel embalmed human and animal liver, fresh animal liver, and compared to gel phantom.
PRF thermometry during MRgFUS was conducted using a 1.5T MRI system. The phantom and the organs were sonicated with the following energies: 300J, 600J, 1000J and 1400J. The temperature increase which was measured using PRF thermometry during sonication was compared to actual temperature rise in the same conditions measured by fibre optic thermocouple.
Sonication of fresh animal liver showed temperature differences varying between 0.27°C and 0.40°C, whereas the phantom results showed temperature differences from 0.23°C to 0.40°C. For the Thiel embalmed organs, the temperature difference varied from 1.17 °C to 3.13°C for the ovine liver, and from 1.3°C to 3.10°C for the human liver.
The temperature differences measured in the fresh liver were small and similar to those found for the gel phantom. However, the temperature differences calculated for the Thiel embalmed organs were higher compared to the fresh organ. This indicates that the PRF-based temperature calibration of the Focused Ultrasound machine for Thiel embalmed tissue is necessary.
本研究的目的是确定在磁共振引导聚焦超声（MRgFUS）消融离体的经蒂尔（Thiel）防腐处理的人和动物肝脏、新鲜动物肝脏过程中质子共振频率（PRF）测温法的准确性，并与凝胶体模进行比较。
使用1.5T磁共振成像系统在MRgFUS过程中进行PRF测温。用以下能量对体模和器官进行超声处理：300J、600J、1000J和1400J。将超声处理过程中使用PRF测温法测得的温度升高与用光纤热电偶在相同条件下测得的实际温度升高进行比较。
新鲜动物肝脏的超声处理显示温度差异在0.27°C至0.40°C之间变化，而体模结果显示温度差异在0.23°C至0.40°C之间。对于经蒂尔防腐处理的器官，绵羊肝脏的温度差异在1.17°C至3.13°C之间，人类肝脏的温度差异在1.3°C至3.10°C之间。
新鲜肝脏中测得的温度差异较小，与凝胶体模中的温度差异相似。然而，与新鲜器官相比，经蒂尔防腐处理的器官计算出的温度差异更高。这表明有必要对经蒂尔防腐处理的组织的聚焦超声机器进行基于PRF的温度校准。
