Daum D R, Hynynen K
MIT and Harvard Division of Health Sciences and Technology, Boston, MA, USA.
Eur J Ultrasound. 1999 Mar;9(1):61-9. doi: 10.1016/s0929-8266(99)00006-3.
The theoretical explanation of the limits of an array transducer to coagulate large tissues volumes.
A theoretical model is used to illustrate the focal limitations of a spherically sectioned array designed for the treatment of deep seated tissue, e.g. liver. The design optimizes the acoustic dose as a function of the focal depth and available acoustic aperture with the goal of coagulating large volumes in a single sonication period. A quantitative measure of the possible region of focal necrosis is modeled as a function of array parameters with the limiting criteria being near field heating and patient pain.
Acoustic simulations show that the maximum distance to produce continuous necrosis between foci in a multiple focus pattern and in a temporally multiplexed pattern is approximately 50% larger than the distance needed between sequential foci.
Multiple focus patterns or rapidly scanned single foci are significantly advantageous to sequential sonications of a single focus transducer.
对阵列换能器凝固大体积组织的局限性进行理论解释。
使用理论模型来说明为治疗深部组织（如肝脏）而设计的球形截面阵列的聚焦局限性。该设计根据聚焦深度和可用声孔径优化声剂量，目标是在单次超声处理期间凝固大体积组织。将局灶性坏死可能区域的定量测量建模为阵列参数的函数，限制标准为近场加热和患者疼痛。
声学模拟表明，在多焦点模式和时间复用模式下，产生连续坏死灶之间的最大距离比连续焦点之间所需的距离大约大50%。
多焦点模式或快速扫描的单焦点对单焦点换能器的顺序超声处理具有显著优势。
