计算机辅助定量分析不同功率微波消融致兔骨骼肌急性损伤修复过程中的超声纹理特征

Computer-aided quantitative analysis of ultrasonic texture characteristics during repair process of rabbit skeletal muscle acute injury caused by microwave ablation of different powers

目的应用计算机辅助诊断技术定量分析不同功率微波消融致兔骨骼肌急性损伤后修复过程中的超声纹理变化。方法44只健康新西兰大白兔,随机选择4只作为正常对照组,不进行微波消融;其余40只随机平均分为30 W和50 W组,在高分辨率超声引导下分别用30 W、50 W功率对右侧股肌肉微波消融3 min。微波消融后1 h、1 d、2 d、7 d、28 d采集右侧下肢股动脉干与股肌肉长轴平面二维超声图像,正常对照组于相同时间点采集图像。运用Matlab 7.0软件提取各组图像感兴趣区包含的8个肌纤维纹理特征(纹理灰度均值、纹理灰度标准差、纹理密致性、纹理基元形状不规则度、纹理基元平均大小、纹理分布均匀性、纹理分布的方向性和纹理分布的周期性)进行肌纹理定量分析。结果在微波消融后1 h、1 d、2 d,30 W组、50 W组微波消融区兔骨骼肌的8个纹理特征均高于正常对照组,差异均有统计学意义(P均<0.05);在微波消融后7 d,30 W组、50 W组兔骨骼肌纹理灰度均值、纹理密致性、纹理基元平均大小、纹理分布均匀性和纹理分布的周期性均高于正常对照组,50 W组兔骨骼肌纹理灰度标准差亦高于正常对照组,差异均有统计学意义(P均<0.05);在微波消融后28 d,30 W组、50 W组兔骨骼肌纹理分布的周期性均高于正常对照组,50 W组兔骨骼肌纹理灰度均值、纹理灰度标准差、纹理密致性、纹理基元平均大小亦均高于正常对照组,差异均有统计学意义(P均<0.05)。在微波消融后1 h、2 d、7 d时50 W组兔骨骼肌纹理灰度均值均高于30 W组,1 h、1 d、2 d、7 d、28 d时50 W组兔骨骼肌纹理灰度标准差均高于30 W组,1 h、1 d时50 W组兔骨骼肌纹理密致性均高于30 W组,2 d时50 W组兔骨骼肌纹理基元形状不规则度高于30 W组,1 d、2 d、7 d、28 d时50 W组兔骨骼肌纹理基元平均大小均高于30 W组,1 d时50 W组兔骨骼肌纹理分布均匀性高于30 W组,1 h、2 d时50 W组兔骨骼肌纹理分布的周期性均高于30 W组,差异均有统计学意义(P均<0.05)。结论应用计算机技术提取的微波消融致兔肌肉急性损伤修复不同时期超声纹理特征可定量描述兔骨骼肌损伤后肌纤维的几何特征,有望为骨骼肌损伤修复临床超声定量诊断提供依据。

Objective To quantitatively analyze the ultrasonic texture changes in the repair process of rabbit skeletal muscle acute injury caused by microwave ablation of different powers by computer-aided diagnosis technology.Methods Four of 44 healthy New Zealand white rabbit served as a normal control group(without microwave ablation),and the other 40 rabbits were randomly divided into 30 W and 50 W groups(n=20).Under the guidance of high-resolution ultrasound,the right femoral muscle was ablated with 30 W or 50 W powers for 3 min.Two-dimensional ultrasound images of long-axis section of femoral artery trunk and femoral muscle of right lower limb were acquired at 1 h,1 day,2 days,7 days and 28 days after microwave ablation,while images of normal control group were acquired at the same time points.Eight muscle fiber texture features(texture grayscale mean,texture grayscale standard deviation,texture number of blobs,texture irregularity of blobs,texture average size of blobs,texture homogeneity of distribution,texture directionality of distribution,and texture periodicity of distribution)included in each image region of interest were extracted by Matlab 7.0 software for quantitative analysis.Results The eight texture features of 30 W group and 50 W group were significantly higher than those of normal control group at 1 h,1 day,2 days after microwave ablation(all P<0.05).Seven days after microwave ablation,the rabbit skeletal muscle texture grayscale mean,texture number of blobs,texture average size of blobs,texture homogeneity of distribution and texture periodicity of distribution in the 30 W group and 50 W group were all significantly higher than those in the normal control group,and texture grayscale standard deviation in the 50 W group was also significantly higher than that in the normal control group(all P<0.05).On the 28th day after microwave ablation,the rabbit skeletal muscle texture periodicity of distribution in the 30 W group and 50 W group was significantly higher than that in the normal control group,and the rabbit skeletal muscle texture grayscale mean,texture grayscale standard deviation,texture number of blobs,and texture average size of blobs in the 50 W group were also significantly higher than those in the normal control group(all P<0.05).After microwave ablation,the texture grayscale mean of the 50 W group was higher than that of the 30 W group at 1 h,2 days and 7 days,the texture grayscale standard deviation of the 50 W group was higher than that of the 30 W group at 1 h,1 day,2 days,7 days and 28 days,the texture number of blobs of the 50 W group was higher than that of the 30 W group at 1 h and 1 day,the texture irregularity of blobs of the 50 W group was higher than that of the 30 W group at 2 days,the texture average size of blobs in the 50 W group was higher than that in the 30 W group at 1 day,2 days,7 days and 28 days,the texture homogeneity of distribution in the 50 W group was higher than that in the 30 W group at 1 day,and the texture periodicity of distribution in the 50 W group was higher than that in the 30 W group at 1 h and 2 days,the differences were statistically significant(all P<0.05).Conclusion Ultrasonic texture features of acute muscle injury repair in rabbits at different stages induced by microwave ablation extracted by computer technology could quantitatively describe the geometric features of muscle fibers after skeletal muscle injury in rabbits,which will be expected to provide evidence for clinical ultrasonic quantitative diagnosis of skeletal muscle injury repair.