Zachary James F, Blue James P, Miller Rita J, Ricconi Brian J, Eden J Gary, O'Brien William D
Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA.
Ultrasound Med Biol. 2006 Nov;32(11):1763-70. doi: 10.1016/j.ultrasmedbio.2006.06.012.
Thermal injury, a potential mechanism of ultrasound-induced lung hemorrhage, was studied by comparing lesions induced by an infrared laser (a tissue-heating source) with those induced by pulsed ultrasound. A 600-mW continuous-wave CO2 laser (wavelength approximately 10.6 microm) was focused (680-microm beamwidth) on the surface of the lungs of rats for a duration between 10 to 40 s; ultrasound beamwidths were between 310 and 930 microm. After exposure, lungs were examined grossly and then processed for microscopic evaluation. Grossly, lesions induced by laser were somewhat similar to those induced by ultrasound; however, microscopically, they were dissimilar. Grossly, lesions were oval, red to dark red and extended into subjacent tissue to form a cone. The surface was elevated, but the center of the laser-induced lesions was often depressed. Microscopically, the laser-induced injury consisted of coagulation of tissue, cells and fluids, whereas injury induced by ultrasound consisted solely of alveolar hemorrhage. These results suggest that ultrasound-induced lung injury is most likely not caused by a thermal mechanism.
通过比较红外激光（一种组织加热源）与脉冲超声所引起的损伤，对热损伤这一超声诱导肺出血的潜在机制进行了研究。一台600毫瓦的连续波二氧化碳激光（波长约10.6微米）聚焦（光束宽度680微米）于大鼠肺部表面，持续时间为10至40秒；超声光束宽度在310至930微米之间。暴露后，对肺部进行大体检查，然后进行显微镜评估。大体上，激光诱导的损伤与超声诱导的损伤有些相似；然而，在显微镜下，它们并不相同。大体上，损伤呈椭圆形，从红色到深红色，并延伸至下方组织形成一个锥体。表面隆起，但激光诱导损伤的中心通常凹陷。显微镜下，激光诱导的损伤包括组织、细胞和液体的凝固，而超声诱导的损伤仅由肺泡出血组成。这些结果表明，超声诱导的肺损伤很可能不是由热机制引起的。
