超声图像纹理分析技术对离体猪横纹肌理化损伤模型的定量研究

A quantitative study on ultrasonographic texture analysis of injured porcine striped muscle induced by thermal and chemical factors

目的探讨超声回波强度界面多级分解法定量分析离体猪横纹肌微波消融热损伤、无水乙酸注射化学损伤后的超声图像纹理变化的应用价值。方法分别以微波消融、无水乙酸注射损伤离体猪横纹肌作为实验研究模型,采用计算机纹理特征自动提取定量分析——超声回波强度界面多级分解法,针对不同损伤区域的横纹肌声像图纹理变化进行对照研究,判断各组所提取的8种反映肌纤维纹理分布数学几何特征参量的统计学差异。结果与正常区域(ROI1)比较,微波消融损伤区域(ROI2)用以定量描述纹理灰度的均值(Mean)、纹理基元形状的不规则度(IRGL)、纹理分布的周期性(POD)的3种纹理特征差异有统计学意义(Mean:1.9143±0.2914 vs 1.2334±0.3357,t=-5.306,P=0.000;IRGL:0.5577±0.0334 vs 0.5092±0.0459,t=-2.957,P=0.007;POD:0.00027±0.000005 vs 0.00029±0.000008,t=4.782,P=0.000);与正常区域(ROI1)比较,无水乙酸注射损伤区域(ROI3)用以定量描述纹理的密致性(NOB)、纹理基元的平均大小(SOB)、POD的3种纹理特征差异有统计学意义(NOB:51.0324±13.6998 vs 31.6042±4.8315,t=4.633,P=0.000;SOB:16.4843±3.9349 vs 25.6230±2.3555,t=6.903,P=0.000;POD:0.00026±0.000015 vs 0.00029±0.000008,t=-4.459,P=0.000);两组理化损伤区域相比,Mean、IRGL、NOB、SOB的4种纹理特征差异有统计学意义(Mean:1.2664±0.2688 vs 1.9143±0.2914,t=-5.661,P=0.000;IRGL:0.5220±0.0422 vs 0.5577±0.0334,t=-2.295,P=0.032;NOB:51.0324±13.6998 vs 34.5856±2.6362,t=4.048,P=0.000;SOB:16.4843±3.9349 vs 25.3176±2.3501,t=-6.676,P=0.000)。结论超声回波强度界面多级分解法能够有效提取横纹肌超声图像中的肌纹理形态、组构及分布状态信息,定量反映出不同理化损伤类型导致横纹肌纹理声像图差异的显著性,初步具备了定量诊断能力。

Objective To quantitatively analyze and compare the texture features of thermal and chemical lesions on the porcine striated muscle,in vitro extracted from high-frequency ultrasonograms using computer-assisted image analysis technique,and to investigate the application values.Methods The thermal lesion and chemical lesion were induced in vitro in porcine striated muscle by microwave ablation and anhydrous acetic acid injection,respectively.The two dimension (2D) ultrasonographic findings were qualitatively compared between the groups of thermal and chemical lesion models,in which eight textural features in geometric mathematics extracted from 2D ultrasonograms were quantitatively analyzed by a technique of computer-assisted image analysis named multiscale decomposition method of echo intensity of interface reflections.Results As expected,microwave ablation and anhydrous acetic acid caused significant changes of several texture features extracted from ultrasonograms.There were significant differences between the normal group and microwave ablation group in grayscale mean (Mean),irregularity (IRGL) and periodicity of distribution (POD) as follows (Mean:1.9143±0.2914 vs 1.2334±0.3357,t=-5.306,P=0.000;IRGL:0.5577±0.0334 vs 0.5092±0.0459,t=-2.957,P=0.007;POD:0.000 27±0.000 005 vs 0.000 29±0.000 008,t=4.782,P=0.000).There were significant differences between the normal group and anhydrous acetic acid injection group in number of blobs (NOB),size of blobs (SOB) and periodicity of distribution (POD) as follows (NOB:51.0324±13.6998 vs 31.6042±4.8315,t=4.633,P=0.000;SOB:16.4843±3.9349 vs 25.6230±2.3555,t=6.903,P=0.000;POD:0.000 26±0.000 015 vs 0.000 29±0.000 008,t=-4.459,P=0.000).For each group of injured regions,there were significant differences between the microwave ablation group and anhydrous acetic acid injection group in Mean,IRGL,NOB and SOB as follows (Mean:1.2664±0.2688 vs 1.9143±0.2914,t=-5.661,P=0.000;IRGL:0.5220±0.0422 vs 0.5577±0.0334,t=-2.295,P=0.032;NOB:51.0324±13.6998 vs 34.5856±2.6362,t=4.048,P=0.000;SOB:16.4843±3.9349 vs 25.3176±2.3501,t=-6.676,P=0.000).Conclusion Technique of computer-assisted image analysis named multiscale decomposition method of echo intensity of interface reflections,based on multiscale blob features extraction,was useful to differentiate ultrasonic texture features between the groups injured in our study,which established quantitative muscle ultrasound as a practical and reliable tool for the muscle injury diagnosis to distinguish the structural changes induced by different physiochemical factors.