| 摘要: |
| 目的 动态观察大鼠骨骼肌在损伤修复不同时期肌肉组织的超声造影图像特征，并分析其与微血管密度的相关性。方法 将48只雄性SD大鼠随机分为8组，其中6只为正常对照组、42只为损伤组（损伤后1 h、12 h、24 h、48 h、7 d、14 d、28 d组）。对于损伤组大鼠选定右侧股直肌肌腹中段为打击中心，采用自由落体击落架，用800 g自制重力锤一次性自由落体进行重力打击，建立大鼠下肢骨骼肌钝挫伤模型。分别于损伤后1 h、12 h、24 h、48 h、7 d、14 d、28 d对大鼠损伤处骨骼肌及正常对照组相应部位进行超声造影检查，利用计算机辅助定量分析超声造影图像特征变化，获得造影剂平均回声强度灰阶值（Mean）。各损伤组大鼠均于超声检查后处死，切取损伤区肌肉组织进行CD34免疫组织化学染色，计算微血管平均光密度值（MVD）。采用Pearson相关分析对骨骼肌损伤区MVD与Mean进行相关性分析。结果 损伤后1 h、12 h组大鼠损伤区骨骼肌造影剂信号微弱，可见充盈缺损；损伤后24 h组损伤区造影剂呈星点状分布，为低增强；损伤后48 h组损伤区造影剂呈斑片状分布，为轻度增强；损伤后7 d组损伤区造影剂信号密集增多，呈高增强；损伤后14 d组损伤区造影剂信号较7 d组减低，呈轻度增强；损伤后28 d组损伤区造影剂信号与正常对照组相似，呈低增强。与正常对照组比较，损伤后1 h、12 h、24 h组损伤区Mean均减低（P均＜0.05），损伤后48 h组Mean略增高但差异无统计学意义（P＞0.05），损伤后7 d组Mean进一步增高达到峰值（P＜0.05），损伤后14 d组Mean仍较高（P＜0.05），损伤后28 d组Mean接近正常对照组水平（P＞0.05）。与损伤后1 h组相比，损伤后12 h组MVD无明显变化（P＞0.05），损伤后24 h至28 d组MVD均增高且以损伤后7 d组最高（P均＜0.05）。大鼠骨骼肌损伤区Mean与MVD呈正相关（r＝0.840，P＜0.001）。结论 超声造影可动态观察受损骨骼肌不同时期的微循环灌注演变，计算机辅助定量分析可快速描述超声造影剂信号强度变化，且与肌肉内微血管分布规律相关性较好。 |
| 关键词: 超声造影 骨骼肌 挫伤 微血管密度 计算机辅助诊断 |
| DOI：10.16781/j.CN31-2187/R.20220725 |
| 投稿时间：2022-09-11修订日期：2022-12-22 |
| 基金项目:国家自然科学基金（81501492），上海市自然科学基金（20ZR1457900），海军军医大学（第二军医大学）第二附属医院人才建设三年行动计划——“金字塔”人才工程军事医学人才项目（1009）. |
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| Correlation of contrast-enhanced ultrasound characteristics and microvascular distribution in a rat skeletal muscle blunt contusion model |
| DIAO Zong-ping1△,XU Qi2△,TANG Xiao-yi3,ZHAO Jia-qi4* |
(1. Department of Ultrasound, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China;
2. Department of Computer Science, College of Information Engineering, Shanghai Maritime University, Shanghai 201306, China;
3. Department of Ultrasound, The Second Affiliated Hospital of Naval Medical University (Second Military Medical University), Shanghai 200003, China;
4. Department of Ultrasound, Shanghai Fourth People's Hospital Affiliated to Tongji University, Shanghai 200434, China
△Co-first authors.
* Corresponding author) |
| Abstract: |
| Objective To dynamically observe the characteristics of contrast-enhanced ultrasound (CEUS) of rat skeletal muscle at different stages of injury and repair, and to analyze the correlation between them and microvascular density. Methods Forty-eight male SD rats were randomly divided into 8 groups, including 6 rats in normal control group and 42 in injured groups (groups of 1 h, 12 h, 24 h, 48 h, 7 d, 14 d and 28 d after injury). A one-time free fall of an 800 g self-made gravity hammer struck the muscle belly of the right rectus femoris of the rats in the injured groups, thus establishing a model of blunt contusion of the skeletal muscle of the lower limb. At 1 h, 12 h, 24 h, 48 h, 7 d, 14 d and 28 d after the injury, CEUS was performed on the injured sites of skeletal muscle of rats in the injured groups and the corresponding sites in the normal control group. The changes of CEUS characteristics were quantitatively analyzed by computer, and the mean gray scale value of echo intensity (Mean) was obtained. After ultrasound examination, the rats in the injured groups were sacrificed to collect the muscle tissue for hematoxylin-eosin staining, and the microvessel average optical density (MVD) was calculated. Pearson correlation analysis was used to analyze the correlation between MVD and Mean in skeletal muscle injury area. Results The contrast agent signals of skeletal muscle in the injured area of rats in the 1 h group and 12 h group were weak, and most of them showed filling defects. In the 24 h group, the contrast agent in the injured area showed star-shaped distribution, which was low enhancement. In the 48 h group, the contrast agent in the injured area showed patchy distribution, which was slightly enhanced. In the 7 d group, the contrast agent signal in the injured area increased intensively, showing obvious enhancement. In the 14 d group, the contrast agent signal in the injured area was slightly enhanced and was lower than that in the 7 d group. In the 28 d group, the signal of contrast agent in the injured area was similar to that in the normal control group, showing low enhancement. Compared with the normal control group, the Mean of the injured area were significantly decreased in the 1 h, 12 h and 24 h groups (all P＜0.05), the Mean of the injured area was increased in the 48 h group without a significant difference (P＞0.05), and the Mean of the injured area was further increased to the peak in the 7 d group and was still higher in the 14 d group with significant differences (both P＜0.05). The Mean of the injured area in the 28 d group was similar to that in the normal control group (P＞0.05). Compared with the 1 h group, the MVD of the 12 h group was not significantly changed (P＞0.05). The MVD of the 24 h to 28 d groups was all significantly increased (all P＜0.05), with the highest in the 7 d group. The Mean was positively correlated with the MVD in the injury area of rats (r＝0.840, P＜0.001). Conclusion CEUS can dynamically observe the microcirculation perfusion of injured skeletal muscle in different periods, and computer-aided image analysis can quantitatively describe the change of the signal intensity of contrast agent, which has good correlation with the distribution of microvessels in the muscle. |
| Key words: contrast-enhanced ultrasound skeletal muscle contusions microvascular density computer-aided diagnosis |
