Intracorporeal needle-based therapeutic ultrasound (NBTU) is a minimally invasive option for intervening in malignant brain tumors, commonly used in thermal ablation procedures. This technique is suitable for both primary and metastatic cancers, utilizing a high-frequency alternating electric field (up to 10 MHz) to excite a piezoelectric transducer. The resulting rapid deformation of the transducer produces an acoustic wave that propagates through tissue, leading to localized high-temperature heating at the target tumor site and inducing rapid cell death. To optimize the design of NBTU transducers for thermal dose delivery during treatment, numerical modeling of the acoustic pressure field generated by the deforming piezoelectric transducer is frequently employed. The bioheat transfer process generated by the input pressure field is used to track the thermal propagation of the applicator over time. Magnetic resonance thermal imaging (MRTI) can be used to experimentally validate these models. Validation results using MRTI demonstrated the feasibility of this model, showing a consistent thermal propagation pattern. However, a thermal damage isodose map is more advantageous for evaluating therapeutic efficacy. To achieve a more accurate simulation based on the actual brain tissue environment, a new finite element method (FEM) simulation with enhanced damage evaluation capabilities was conducted. The results showed that the highest temperature and ablated volume differed between experimental and simulation results by 2.1884{\deg}C (3.71%) and 0.0631 cm$^3$ (5.74%), respectively. The lowest Pearson correlation coefficient (PCC) for peak temperature was 0.7117, and the lowest Dice coefficient for the ablated area was 0.7021, indicating a good agreement in accuracy between simulation and experiment.

翻译：体内针式治疗性超声（NBTU）是干预恶性脑肿瘤的一种微创选择，常用于热消融手术。该技术适用于原发性和转移性癌症，利用高频交变电场（高达10 MHz）激发压电换能器。换能器随之产生的快速形变产生声波，该声波在组织中传播，导致目标肿瘤部位局部高温加热并诱发快速细胞死亡。为优化治疗期间热剂量输送的NBTU换能器设计，常采用数值模拟来刻画形变压电换能器产生的声压场。输入压力场产生的生物热传递过程用于追踪施热器随时间的热传播。磁共振热成像（MRTI）可用于实验验证这些模型。使用MRTI的验证结果证明了该模型的可行性，显示出一致的热传播模式。然而，热损伤等剂量图对于评估治疗效果更具优势。为了基于实际脑组织环境实现更精确的模拟，我们进行了一种具备增强损伤评估能力的新有限元法（FEM）模拟。结果显示，实验与模拟结果的最高温度与消融体积分别相差2.1884°C（3.71%）和0.0631 cm³（5.74%）。峰值温度的最低皮尔逊相关系数（PCC）为0.7117，消融区域的最低Dice系数为0.7021，表明模拟与实验在准确性上具有良好的一致性。