肝组织超声图像特征参数与温度相关性研究

Study on Correlation of Temperature and Liver Tissue Ultrasound Image Features

热疗过程中对组织温度进行实时无创监测是近年来研究的热点和难点。本文对新鲜离体猪肝进行水浴加热实验并采集超声图像;分析了固定感兴趣区域数字减影图像的灰度直方图、灰度共生矩阵和灰度-梯度共生矩阵特征参数与温度的相关性。分析结果表明,其中灰度均值、灰度标准差、灰度熵;4个方向(0°4,5°9,0°,135°)上的角二阶矩、对比度、逆差矩、相关;灰度分布不均匀性、能量、混合熵、惯性在26～45℃范围内与温度具有较高的相关性。以上11个图像特征可为选择测温模型参数提供参考,并有望应用于组织高温热疗凝固区检测等实际问题。

Non-invasive real-time temperature monitoring of tissue is a difficult problem and hot issue in hyperthermia. In this paper, fresh in vitro porcine liver tissues were heated in water-bath and the ultrasound images were acquired. The correlation of temperature and features, including gray level histogram, gray level co-occurrence matrix and gray level-gradient level co-occurrence matrix extracted from differential ultrasound images was analyzed. The results showed that 11 features of image were high correlated with tissue temperature from 26℃ to 45℃. These features included the mean values, standard deviation and entropy based on gray level histogram, the angular second moment, contrast, inverse difference moment and correlation in four directions （0°, 45°, 90°, 135°） , un-uniformity, energy, mixed entropy and inertia. The proposed 11 image features can help to construct the model of temperature measurement, it may be used for coagulation detecting in hyperthermia.