| 摘要: |
| 目的 应用实时超声弹性成像技术，观察不同消融功率致兔骨骼肌损伤后肌肉组织弹性的自然恢复情况。方法 44只新西兰大白兔，其中4只作为正常对照（正常组），余40只随机分为2组：30 W组和50 W组，分别在高频超声引导下用2 450 MHz的微波消融仪（KY-2100型）启动30 W或50 W功率微波热凝右侧股内侧肌肉3 min。分别于消融后1 h、1 d、2 d、7 d、28 d时行超声弹性成像检查，计算消融区弹性应变率（SR）；并于每个时间点切取30 W和50 W组兔右侧股内侧热凝固化肌肉组织与正常组兔同侧相同区域肌肉组织，进行病理组织学观察。结果 30 W和50 W组兔骨骼肌消融区以蓝色为主，消融后7 d可见以蓝色为主的消融区内出现较多绿色，而在消融后28 d时50 W组消融区比30 W组仍有更多蓝色。与正常组比较，消融后1 h、1 d、2 d，30 W和50 W组兔骨骼肌消融区SR均增高，差异均有统计学意义（P<0.05、P<0.01）；消融后7 d、28 d，两组兔骨骼肌消融区SR逐渐降低，但两组在消融后7 d时SR仍高于正常组，差异均有统计学意义（P<0.05、P<0.01），而在28 d时仅50 W组与正常组相比差异有统计学意义（P<0.01），30 W组SR与对照组相近（P>0.05）。H-E染色结果显示，30 W和50 W组兔骨骼肌消融区有不同程度组织损伤、碳化、周边肌纤维凝固性坏死。消融后1～2 d消融区中心与边缘交界处可见炎症细胞浸润，50 W组巨噬细胞较30 W组增加更多；消融后7～28 d时30 W和50 W组交界处可见大量新生血管和成纤维细胞及瘢痕形成，炎症、浊肿等减轻。Masson染色结果显示，消融后1 h时，30 W和50 W组兔骨骼肌纤维含量较少，无明显纤维增生，消融后1～2 d交界处可见不同程度新生胶原纤维，肌间质纤维增生；消融后7～28 d交界处可见明显大量新生胶原纤维并伴随血管壁周边纤维明显增多。天狼星红染色结果显示，消融后30 W和50 W组交界处可见逐渐增生的新生胶原纤维修复损伤区。消融后1 h和1 d时两组主要为Ⅰ型胶原纤维；消融后2 d时不仅有Ⅰ型胶原纤维，还开始出现Ⅱ型胶原纤维；消融后7 d和28 d时可见较多Ⅱ型胶原纤维呈网状分布。结论 不同功率微波消融可致兔骨骼肌急性损伤，在消融后1～2 d进行性加重，消融后7～28 d呈修复趋势，50 W组修复晚于30 W组。实时超声弹性成像与病理组织学的再生纤维化趋势改变较为一致，可动态、无创评估肌肉损伤修复不同时期相应组织的弹性变化，从而间接反映骨骼肌的损伤后修复过程，是常规超声检查的有益补充。 |
| 关键词: 超声检查 骨骼肌 微波消融术 损伤 修复 弹性成像 |
| DOI：10.16781/j.0258-879x.2019.09.0970 |
| 投稿时间：2019-02-19修订日期：2019-06-19 |
| 基金项目:国家自然科学基金青年科学基金（81501492），长征医院青年启动基金（2012CZQN11）. |
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| Real-time ultrasound elastography in evaluating dynamic changes of rabbit skeletal muscle injury induced by microwave ablation of different powers |
| ZHAO Jia-qi1,ZHANG Jian-quan1*,ZHAO Lu-lu2,SONG Jia-lin1,PAN Qian1,SHENG Jian-guo1,LIU Shi-yuan3* |
(1. Department of Ultrasound, Changzheng Hospital, Naval Medical University(Second Military Medical University), Shanghai 200003, China;
2. Department of Ultrasound, Changhai Hospital, Naval Medical University(Second Military Medical University), Shanghai 200433, China;
3. Department of Imaging, Changzheng Hospital, Naval Medical University(Second Military Medical University), Shanghai 200003, China
*Corresponding authors) |
| Abstract: |
| Objective To use ultrasound elastography for observing the natural recovery of rabbit muscle elasticity after skeletal muscle injury induced by microwave ablation of different powers. Methods Forty New Zealand white rabbits were randomly divided into 30 W group and 50 W group, with 20 in each group. Another 4 rabbits served as normal controls (normal group). Rabbit models of skeletal muscle injury were established by microwave thermocoagulation with different powers (30 W and 50 W) for the right medial femoral muscle for 3 min using the KY-2100 microwave ablation instrument (2 450 MHz). One hour, and 1, 2, 7 and 28 d after microwave ablation, ultrasound elastography feature strain ratio (SR) values in ablation areas were calculated. At each time point, the thermocoagulated muscle tissue of the right medial femoral muscle in the 30 W and 50 W groups and the muscle tissue of the same area on the same side in the normal group were harvested for pathological observation. Results The ablation areas extracted from ultrasound elastography were mainly blue in the 30 W and 50 W groups, while green area appeared in those areas 7 d after microwave ablation. More blue areas were seen in 50 W group compared with 30 W group 28 d after microwave ablation. Compared with the normal group, the SR values in the 30 W and 50 W groups were significantly increased 1 h, 1 d, and 2 d after microwave ablation (P<0.05, P<0.01). At 7 d and 28 d after microwave ablation, the SR values gradually decreased in the 30 W and 50 W groups; but SR values in the two groups were still significantly higher than that in the normal group 7 d after microwave ablation (P<0.05, P<0.01); while 28 d after microwave ablation, SR value of 50 W group was significantly different compared with the normal group (P<0.01), SR value in the 30 W group was similar to that in the control group (P>0.05). H-E staining showed different degrees of tissue damage, carbonization, and coagulation necrosis of peripheral muscle fibers. Inflammatory cell infiltration was seen at the injured junction 1-2 d after microwave ablation, and the macrophages in the 50 W group was more than that in the 30 W group. A large number of neovascularization, fibroblasts and scar formation were observed at the junction 7-28 d after microwave ablation, and inflammation and turbidity swelling were alleviated in the 30 W and 50 W groups. Masson staining showed less fiber contents and no obvious fiber proliferation 1 h after microwave ablation in the 30 W and 50 W groups. At 1-2 d after microwave ablation, different degrees of new collagen fibers and muscle interstitial fiber proliferation were observed in the 30 W and 50 W groups. At 7-28 d after microwave ablation, a large number of newborn collagen fibers were observed in the 30 W and 50 W groups, accompanied by a significant increase in peripheral fibers of vascular wall. Sirius red staining showed that a large number of newborn collagen gradually appeared in the 30 W and 50 W groups. Immediately and 1 d after microwave ablation, there were mainly typeⅠcollagen fibers, and typeⅡcollagen fibers were found 2 d after microwave ablation. At 7 d and 28 d after microwave ablation, there were more typeⅡcollagen fibers reticulated in the 30 W and 50 W groups. Conclusion Microwave ablation with different powers can cause acute muscle injury in rabbits, the injury intensifies during 1-2 d after microwave ablation, and begin to repair 7-28 d after microwave ablation; the repair of 50 W group is later than the 30 W group. The dynamic changes of ultrasound elastography are consistent with the pathological findings. Ultrasound elastography can noninvasively evaluate the dynamic changes of skeletal muscle tissue repair after muscle injury, and it is a complement to the conventional ultrasound examination. |
| Key words: ultrasonography skeletal muscle microwave ablation injury repair elastography |
