Laugier P, Berger G
URA CNRS 1458 Imagerie Paramétrique, Paris, France.
Ultrason Imaging. 1993 Jan;15(1):14-24. doi: 10.1177/016173469301500102.
One of the principal difficulties encountered in cryosurgery is to know the extent and depth of the frozen tissue boundary during the freezing process and the extent of the cryonecrosis in the postfreezing period. These problems have to be solved for cryosurgery to be a controlled therapeutic method and to avoid injuries to tissues adjacent to the tumor. The aim of this study was to evaluate echographic possibilities in monitoring the freezing process during cryotherapy in dermatology. In this paper, we describe the first experimental results of ultrasound monitoring of the freezing process with a 15 MHz transducer on pig skin in vitro. We show that it is possible to easily detect the depth boundary of the frozen region. Conventional linear filtering of the echographic signals can be very useful for SNR enhancement in the detection of a target signal drowned in speckle noise. Measurement of the kinetics of the freeze-thaw cycle (thickness of the frozen region versus time) is also measurable, which is of major importance as it allows the exact adjustment of the freezing time as a function the extent of tumor depth. Cryotherapy monitoring by ultrasound, added to the new diagnostic possibilities of high frequency ultrasound transducers, makes it an interesting controlled therapeutic method in such clinical fields as dermatology.
冷冻手术中遇到的主要困难之一是在冷冻过程中了解冷冻组织边界的范围和深度，以及冷冻后时期内冷冻坏死的范围。为了使冷冻手术成为一种可控的治疗方法并避免对肿瘤邻近组织造成损伤，必须解决这些问题。本研究的目的是评估超声在皮肤科冷冻治疗过程中监测冷冻过程的可能性。在本文中，我们描述了使用15MHz换能器在体外猪皮上对冷冻过程进行超声监测的首批实验结果。我们表明，可以轻松检测出冷冻区域的深度边界。对超声信号进行传统的线性滤波对于增强淹没在散斑噪声中的目标信号的信噪比非常有用。冻融循环动力学（冷冻区域厚度与时间的关系）的测量也是可测的，这一点非常重要，因为它可以根据肿瘤深度的范围精确调整冷冻时间。超声对冷冻治疗的监测，加上高频超声换能器的新诊断可能性，使其成为皮肤科等临床领域中一种有趣的可控治疗方法。
