Texture analysis with a new method in which the region of interest is segmented into multiple layers for radiofrequency amplitude histogram analysis of fibrous rat livers.
Texture analysis with a new method in which the region of interest is segmented into multiple layers for radiofrequency amplitude histogram analysis of fibrous rat livers.
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DOI：
10.1007/s10396-003-0004-5
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发表时间：
2004-03-01
期刊：
影响因子：
--
通讯作者：
Itoh, Kouichi
中科院分区：
文献类型：
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作者：
Fujii, Yasutomo;Taniguchi, Nobuyuki;Itoh, Kouichi
目得：本研究的目的是估计纤维化的严重程度，而无需活检。方法：信号噪声比（SNR），偏度和峰度进行了测量，使用10 MHz的传感器与纹理分析结合的另一种方法，用于评估纤维大鼠肝脏。该方法将感兴趣区域（ROI）分割成多个层（子ROI）。在均匀介质的每个子ROI中，射频（RF）后向散射回波的包络幅度的直方图类似于瑞利分布。理论上，瑞利统计的SNR、偏度和峰度是恒定的，并且与平均散射强度无关，平均散射强度会因组织衰减、光束衍射和入射波形等不良效应而增强。因此，作为对应的子ROI值的平均值的这些值构成无偏估计器。所有肝纤维化标本均采用二甲基亚硝胺法诱导。纤维含量定量估计的纤维化指数通过计算机处理的病理图像获得的光学microscopic.RESULTS：SNR，偏度和峰度，表示为平均值的相应值从每个子ROI，与纤维化index.CONCLUSION：这些结果使得它有可能预测肝纤维化的严重程度，而无需诉诸活检获得的数据。从我们早期对大鼠的研究中获得的数据，可以通过测量这三个值来定量地评估人类肝炎。该方法可以无创地估计慢性肝病的严重程度。
PURPOSE: The aim of this study was to estimate the severity of fibrosis without a biopsy.METHODS: The signal-to-noise ratio (SNR), skewness, and kurtosis were measured using a 10-MHz transducer with the texture analysis in conjunction with an alternative method for evaluating fibrous rat livers. This method segments the region of interest (ROI) into multiple layers (sub-ROIs). In each sub-ROI of a homogeneous medium, the histogram of enveloped amplitude of radiofrequency (RF) backscattered echoes resembles a Rayleigh distribution. In theory, SNR, skewness, and kurtosis for Rayleigh statistics are constant and independent of the mean scattering intensity, which is enhanced by such undesirable effects as tissue attenuation, beam diffraction, and incident waveforms. Thus, these values, which are averages of the corresponding sub-ROI values, constitute an unbiased estimator. All fibrous liver specimens were induced using the dimethylnitrosamine method. Fiber content was estimated quantitatively as the fibrosis index by computer processing of pathological images obtained by light microscopy.RESULTS: The SNR, skewness and kurtosis, expressed as averages of corresponding values from each sub-ROI, correlated closely with the fibrosis index.CONCLUSION: These results make it possible to predict the severity of liver fibrosis from data obtained without resorting to biopsy. The data, obtained from our earlier study on rats, may be used to evaluate human hepatitis quantitatively by measuring these three values. The method may make it possible to estimate the degree of severity of chronic liver disease noninvasively.