Abstract：
Background: High intensity focused ultrasound (HIFU) can destroy tissue by thermal ablation which may be accompanied by acoustic cavitation and/or tissue water boiling, but the biological and histological effects of these treatments have not been fully documented. Here, detailed histological analysis over time using well characterized HIFU exposures in in vivo rat livers is described.
Methods: Exposures used invoked either (i) thermal, with acoustic cavitation and/or tissue water boiling or (ii) predominantly thermal damage. Cavitation activity was detected using both active and passive methods. Histological assessment involved hematoxylin and eosin (H&E), picrosirius red and immunohistochemical staining.
Results: Distinct concentric damage regions were identified after HIFU exposures. The outermost ring showed a red H&E-stained rim that was characterized by hemorrhage. The adjacent inner band appeared white due to increased extracellular spaces. The morphology of the next zone depended on the exposure. Where there was no tissue acoustic cavitation/water boiling, this was the lesion center, in which heat-fixed cells were seen. Where acoustic cavitation/boiling occurred, a centermost zone with irregular holes up to several hundred microns across was seen. Cleaved caspase-3 and Hsp70 staining in the periphery of both types of HIFU exposures was seen within the outermost ring of hemorrhage, where an inflammatory response was also observed. By day 7, a distinct acellular region in the center of the HIFU lesions had been created.
Conclusions: These results identify the morphological effects and elucidate the similarities and differences of HIFU-induced thermal lesions in the presence or absence of acoustic cavitation/tissue water boiling.
Methods: Exposures used invoked either (i) thermal, with acoustic cavitation and/or tissue water boiling or (ii) predominantly thermal damage. Cavitation activity was detected using both active and passive methods. Histological assessment involved hematoxylin and eosin (H&E), picrosirius red and immunohistochemical staining.
Results: Distinct concentric damage regions were identified after HIFU exposures. The outermost ring showed a red H&E-stained rim that was characterized by hemorrhage. The adjacent inner band appeared white due to increased extracellular spaces. The morphology of the next zone depended on the exposure. Where there was no tissue acoustic cavitation/water boiling, this was the lesion center, in which heat-fixed cells were seen. Where acoustic cavitation/boiling occurred, a centermost zone with irregular holes up to several hundred microns across was seen. Cleaved caspase-3 and Hsp70 staining in the periphery of both types of HIFU exposures was seen within the outermost ring of hemorrhage, where an inflammatory response was also observed. By day 7, a distinct acellular region in the center of the HIFU lesions had been created.
Conclusions: These results identify the morphological effects and elucidate the similarities and differences of HIFU-induced thermal lesions in the presence or absence of acoustic cavitation/tissue water boiling.
摘要：
背景：高强度聚焦超声（HIFU）可以通过热消融破坏组织，这可能伴随着声空化和/或组织水沸腾，但是这些治疗的生物学和组织学效果尚未得到充分记录。这里,描述了使用体内大鼠肝脏中特征良好的HIFU暴露随时间的详细组织学分析。
方法：使用的暴露调用(I)热，具有声空化和/或组织水沸腾或（ii）主要是热损伤。使用主动和被动方法检测空化活动。组织学评估涉及苏木精和曙红（H&E），黄连红及免疫组织化学染色。
结果：HIFU暴露后，确定了不同的同心损伤区域。最外面的环显示红色H&E染色的边缘,其特征在于出血。由于细胞外间隙增加，相邻的内部带呈白色。下一个区域的形态取决于曝光。在没有组织声空化/水沸腾的地方，这是病变中心,在其中可以看到热固定的细胞。发生声空化/沸腾的地方，看到一个最中心的区域，不规则的孔宽达几百微米。两种类型的HIFU暴露周围的caspase-3和Hsp70染色均在出血的最外环内可见，其中也观察到炎症反应。到第7天,已经在HIFU病变的中心产生了不同的无细胞区域。
结论：这些结果确定了在存在或不存在声空化/组织水沸腾的情况下HIFU诱导的热损伤的形态学效应，并阐明了其异同。
方法：使用的暴露调用(I)热，具有声空化和/或组织水沸腾或（ii）主要是热损伤。使用主动和被动方法检测空化活动。组织学评估涉及苏木精和曙红（H&E），黄连红及免疫组织化学染色。
结果：HIFU暴露后，确定了不同的同心损伤区域。最外面的环显示红色H&E染色的边缘,其特征在于出血。由于细胞外间隙增加，相邻的内部带呈白色。下一个区域的形态取决于曝光。在没有组织声空化/水沸腾的地方，这是病变中心,在其中可以看到热固定的细胞。发生声空化/沸腾的地方，看到一个最中心的区域，不规则的孔宽达几百微米。两种类型的HIFU暴露周围的caspase-3和Hsp70染色均在出血的最外环内可见，其中也观察到炎症反应。到第7天,已经在HIFU病变的中心产生了不同的无细胞区域。
结论：这些结果确定了在存在或不存在声空化/组织水沸腾的情况下HIFU诱导的热损伤的形态学效应，并阐明了其异同。
