Department of Biomedical Engineering, University of California, Davis, CA 95616, USA.
IEEE Trans Biomed Eng. 2010 Jan;57(1):155-66. doi: 10.1109/TBME.2009.2029703.
A new system is presented for generating controlled tissue heating with a clinical ultrasound scanner, and initial in vitro and in vivo results are presented that demonstrate both transient and sustained heating in the mild-hyperthermia range of 37 ( degrees )C-42 ( degrees )C. The system consists of a Siemens Antares ultrasound scanner, a custom dual-frequency three-row transducer array and an external temperature feedback control system. The transducer has two outer rows that operate at 1.5 MHz for tissue heating and a center row that operates at 5 MHz for B-mode imaging to guide the therapy. We compare the field maps obtained using a hydrophone against calculations of the ultrasound beam based on monochromatic and linear assumptions. Using the finite-difference time-domain (FDTD) method, we compare predicted time-dependent thermal profiles to measured profiles for soy tofu as a tissue-mimicking phantom. In vitro results show differential heating of 6 ( degrees )C for chicken breast and tofu. In vivo tests of the system were performed on three mice bearing Met-1 tumors, which is a model of aggressive, metastatic, and highly vascular breast cancer. In superficially implanted tumors, we demonstrate controlled heating to 42 ( degrees )C. We show that the system is able to maintain the temperature to within 0.1 ( degrees )C of the desired temperature both in vitro and in vivo.
提出了一种新的系统，用于在临床超声扫描仪中产生受控的组织加热，并且呈现了初步的体外和体内结果，这些结果证明了在 37°C-42°C 的轻度热疗范围内的瞬态和持续加热。该系统由西门子 Antares 超声扫描仪、定制的双频三排换能器阵列和外部温度反馈控制系统组成。换能器有两个外排，工作频率为 1.5MHz，用于组织加热，还有一个中心排，工作频率为 5MHz，用于 B 模式成像以指导治疗。我们将使用水听器获得的场图与基于单色和线性假设的超声束计算进行比较。使用有限差分时域（FDTD）方法，我们将预测的时变热分布与作为组织模拟体模的大豆豆腐的测量分布进行比较。体外结果表明，鸡胸肉和豆腐的温差为 6°C。在三只患有 Met-1 肿瘤的小鼠上进行了系统的体内测试，Met-1 肿瘤是一种侵袭性、转移性和高度血管化的乳腺癌模型。在表面植入的肿瘤中，我们证明了可以将温度控制在 42°C。我们表明，该系统无论是在体外还是体内都能够将温度保持在所需温度的 0.1°C 以内。
