基于fMRI的近似熵和ReHo在肠易激综合征检测中的敏感性和有效性比较

Comparison between approximate entropy and regional homogeneity for identification of irritable bowel syndrome based on functional magnetic resonance imaging

目的比较基于功能磁共振成像(fMRI)数据的熵分析方法和热门的局部一致性(ReHo)方法在检测肠易激综合征患者脑活动状态的有效性和敏感性。方法本研究基于54例肠易激综合征(IBS)患者与54例健康被试的静息态fMRI数据,计算所有被试体素水平上的近似熵(ApEn)。然后采用双样本t检验进行特征筛选,并用支持向量机方法对两组被试进行分类判别,得到不同特征数目下的分类性能,并将该结果与ReHo获得的特征分类性能进行对比。结果IBS患者与健康对照组ReHo在左侧三角部额下回、右侧顶下缘角回、左侧颞下回、左侧颞中回、左侧舌回、双侧枕中回和双侧枕上回区域差异具有统计学意义(P<0.05),ApEn在双侧中央后回、右侧中央前回、右侧颞下回、双侧颞中回和左侧枕上回区域差异存在统计学意义(P<0.05)。而且,无论特征数目如何变化,以ApEn为特征的识别效果均优于以ReHo为特征的识别效果。以ApEn为特征得到的分类正确率、特异性和敏感性可高达93.5%、90.7%与96.2%,而以ReHo为特征得到的分类正确率、特异性和敏感性则高达86.1%、85.1%与87.0%。结论与ReHo方法相比,基于fMRI的熵分析方法在IBS的识别和诊断中具有更高的敏感性和有效性。

Objective To compare the effectiveness and sensitivity of entropy and regional homogeneity (ReHo) for identifying irritable bowel syndrome (IBS) based on functional magnetic resonance imaging (fMRI).Methods Voxel-based approximate entropy (ApEn) was calculated based on findings of resting fMRI of 54 patients with IBS and 54 healthy control subjects. Feature selection was performed using independent sample t-test,and support vector machine was then used to classify and identify different groups.The classification performance obtained from ApEn was compared with that from ReHo.Results Significant differences between the two groups were found in the left triangle part of inferior prefrontal gyrus,right angular gyrus of the inferior parietal lobule,left inferior temporal gyrus,left middle temporal gyrus,left lingual gyrus,bilateral middle occipital gyrus and bilateral superior occipital gyrus for ReHo (P<0.05),and in the bilateral postcentral gyrus,right precentral gyrus,right inferior temporal gyrus,bilateral middle temporal gyrus and left superior occipital gyrus for ApEn (P<0.05).ApEn consistently showed better performance than ReHo regardless of the variations in the number of features.The classification accuracy,specificity and sensitivity of ApEn were 93.5185%,90.7407% and 96.2963%,respectively,as compared with 86.1111%, 85.1852% and 87.037% of ReHo.Conclusion Entropy analysis based on fMRI can be more sensitive and effective than ReHo for identification of IBS.