Guiot C, Cavalli R, Gaglioti P, Danelon D, Musacchio C, Trotta M, Todros T
Department of Neuroscience, University of Torino, Physiology Section, C. Raffaello 30, 10125 Torino, Italy.
Ultrasonics. 2004 Apr;42(1-9):927-30. doi: 10.1016/j.ultras.2003.11.003.
Invasiveness of temperature monitoring devices is presently one of the most serious limitations to the application of oncological hyperthermia (HT). A promising approach aims at detecting temperature variations by monitoring the mean grey level (MGL) of the ultrasonographic image of the tissue. Gaseous ultrasound contrast agents (UCA), enhancing Ultrasonic (US) imaging, are expected to be sensitive to temperature, and are therefore a good candidate as temperature monitoring medium. The present study evaluates the 'in vitro' temporal and thermal stability and the correlation between temperature and MGL using a gaseous UCA (SonoVue) as phantom. No statistical differences were detected between the MGL value of the phantom kept at 43.5 degrees C before (215.2+/-3.5) and after 1 h (214.8+/-2.5), showing good stability at HT temperatures. Data of MGL image vs. temperature were obtained during both heating and cooling experiments in the HT range (30-43 degrees C). A good linearity of MGL vs. temperature (R2=0.976) was found with a good accuracy (2.5%) and a sensitivity of about 6.6 MGL/degrees C.
温度监测设备的侵入性是目前肿瘤热疗（HT）应用中最严重的限制之一。一种有前景的方法旨在通过监测组织超声图像的平均灰度水平（MGL）来检测温度变化。气态超声造影剂（UCA）可增强超声（US）成像，有望对温度敏感，因此是作为温度监测介质的良好候选者。本研究使用气态UCA（声诺维）作为模型，评估其“体外”的时间和热稳定性以及温度与MGL之间的相关性。在43.5℃下保存1小时前后，模型的MGL值之间未检测到统计学差异（之前为215.2±3.5，之后为214.8±2.5），表明在热疗温度下具有良好的稳定性。在热疗温度范围（30 - 43℃）的加热和冷却实验过程中均获得了MGL图像与温度的数据。发现MGL与温度具有良好的线性关系（R2 = 0.976），具有良好的准确性（2.5%）和约6.6 MGL/℃的灵敏度。
