Experimental measurement of microwave ablation heating pattern and comparison to computer simulations.
Experimental measurement of microwave ablation heating pattern and comparison to computer simulations.
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DOI：
10.1080/02656736.2016.1206630
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发表时间：
2017-03
期刊：
影响因子：
--
通讯作者：
Haemmerich D
中科院分区：
文献类型：
--
作者：
Deshazer G;Prakash P;Merck D;Haemmerich D
对于微波消融（MWA）的计算模型，天线设计的知识是必要的，但临床施源器的专有设计往往是未知的。我们通过实验表征了MWA期间的比吸收率（SAR），并与多物理模拟进行了比较。红外（IR）摄像机用于测量分离离体肝脏模型中MWA期间的SAR。将Perseon Medical的短尖端（ST）或长尖端（LT）MWA天线放置在组织样本（n=6）的顶部，并施加微波功率（15 W）6 min，同时间歇性中断功率。通过红外摄像机（3.3 fps，320×240分辨率）记录组织表面温度。根据断电前后的温度斜率间歇计算SAR。温度和SAR数据进行了比较，模拟结果。一旦组织温度超过100 °C，实验测量的SAR就会发生显著变化，这与模拟结果相反。模拟和实验的消融区直径分别为1.28 cm和1.30 ± 0.03 cm（横向）以及2.10 cm和2.66 ± −0.22 cm（轴向）。模拟和实验之间的平均温差为5.6 °C（ST）和6.2 °C（LT）。1000 W/kg SAR等值线的骰子系数为0.74 ± 0.01（ST）和0.77（± 0.03）（LT），表明SAR等值线具有良好的一致性。我们通过实验证明了MWA消融过程中SAR的变化，这在模拟中不存在，表明介电特性不准确。当天线几何形状未知时，测量的SAR可以用于简化的计算机模拟以预测组织温度。
For computational models of microwave ablation (MWA), knowledge of the antenna design is necessary, but the proprietary design of clinical applicators is often unknown. We characterized the specific absorption rate (SAR) during MWA experimentally and compared to a multi-physics simulation. An infrared (IR) camera was used to measure SAR during MWA within a split ex vivo liver model. Perseon Medical’s short-tip (ST) or long-tip (LT) MWA antenna were placed on top of a tissue sample (n=6), and microwave power (15W) was applied for 6 min, while intermittently interrupting power. Tissue surface temperature was recorded via IR camera (3.3 fps, 320×240 resolution). SAR was calculated intermittently based on temperature slope before and after power interruption. Temperature and SAR data were compared to simulation results. Experimentally measured SAR changed considerably once tissue temperatures exceeded 100 °C, contrary to simulation results. The ablation zone diameters were 1.28 cm and 1.30 ± 0.03 cm (transverse), and 2.10 cm and 2.66 ± −0.22 cm (axial), for simulation and experiment, respectively. The average difference in temperature between the simulation and experiment were 5.6 °C (ST) and 6.2 °C (LT). Dice coefficients for 1000 W/kg SAR iso-contour were 0.74 ± 0.01 (ST) and 0.77 (± 0.03) (LT), suggesting good agreement of SAR contours. We experimentally demonstrated changes in SAR during MWA ablation, which were not present in simulation, suggesting inaccuracies in dielectric properties. The measured SAR may be used in simplified computer simulations to predict tissue temperature when the antenna geometry is unknown.
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DOI：
10.3109/02656736.2013.799295
发表时间：
2013-06
期刊：
International journal of hyperthermia : the official journal of European Society for Hyperthermic Oncology, North American Hyperthermia Group
影响因子：
--
作者：
Chiang J;Wang P;Brace CL
通讯作者：
Brace CL
影响因子：
3.8
作者：
Deshazer, Garron;Merck, Derek;Prakash, Punit
通讯作者：
Prakash, Punit
影响因子：
4.6
作者：
Prakash, Punit;Converse, Mark C.;Mahvi, David M.
通讯作者：
Mahvi, David M.
DOI：
10.1109/tmtt.1968.1127484
发表时间：
1971-01-01
影响因子：
4.3
作者：
GUY, AW
通讯作者：
GUY, AW
影响因子：
19.7
作者：
Ahmed, Muneeb;Kumar, Gaurav;Goldberg, S. Nahum
通讯作者：
Goldberg, S. Nahum