Hutchinson E B, Hynynen K
Brigham and Women's Hospital, Boston, Massachusetts, USA.
Med Phys. 1998 Dec;25(12):2392-9. doi: 10.1118/1.598450.
A 62 element MRI-compatible linear phased array was designed and constructed to investigate the feasibility of using transrectal ultrasound for the thermal therapeutic treatment of prostate cancer and benign prostatic hyperplasia. An aperiodic design technique developed in a previous study was used in the design of this array, which resulted in reduced grating lobe levels by using an optimized random distribution of unequally sized elements. The element sizes used in this array were selected to be favorable for both grating lobe levels as determined by array aperiodicity and array efficiency as determined by width to thickness ratios. The heating capabilities and MRI compatibility of the array were tested with in vivo rabbit thigh muscle heating experiments using MRI temperature monitoring. The array produced therapeutic temperature elevations in vivo at depths of 3-6 cm and axial locations up to 3 cm off the central axis and increased the size of the heated volume with electronic scanning of a single focus. The ability of this array to be used for ultrasound surgery was demonstrated by creating necrosed tissue lesions in vivo using short high-power sonications. The ability of the array to be used for hyperthermia was demonstrated by inducing therapeutic temperature elevations for longer exposures. Based on the acoustic and heating performance of this array, it has the potential to be clinically useful for delivering thermal therapies to the prostate and other target volumes close to body cavities.
设计并构建了一个62阵元的磁共振成像兼容线性相控阵，以研究经直肠超声用于前列腺癌和良性前列腺增生热治疗的可行性。本研究采用了先前研究中开发的非周期设计技术，通过优化不等尺寸阵元的随机分布，降低了旁瓣电平。选择该阵列中使用的阵元尺寸，既有利于由阵列非周期性决定的旁瓣电平，又有利于由宽厚比决定的阵列效率。通过使用磁共振温度监测的体内兔大腿肌肉加热实验，测试了该阵列的加热能力和磁共振兼容性。该阵列在体内3 - 6厘米深度和距中心轴3厘米以内的轴向位置产生了治疗性温度升高，并通过单焦点电子扫描增加了加热体积的大小。通过在体内使用短时间高功率超声处理创建坏死组织病变，证明了该阵列用于超声手术的能力。通过长时间暴露诱导治疗性温度升高，证明了该阵列用于热疗的能力。基于该阵列的声学和加热性能，它有可能在临床上用于向前列腺和其他靠近体腔的目标体积提供热疗法。
