Fig 1.
Experimental acquisition of ultrasonic images for porcine liver tissues.
(a) Measure the porcine liver tissue to control the size of each sample. (b) The schematic diagram of the experimental system. (c) The set-up of the experimental system, when the temperature reading of the electronic thermometer was the same as that of the water tank thermometer, the temperature inside the porcine liver became uniform, and then the ultrasound echo signal collected and stored in the computer for further data analysis.
Fig 2.
Reconstruction of B-mode images.
(a) The ultrasound RF data of one frame B-mode image. (b) Reconstruction B-mode ultrasound image of liver tissue at 20°C during water-bath experiment which represented normal structure, and ROI was selected manually from the images for each sample. (c) Steps for image reconstruction from ultrasound RF signals. (d) Reconstruction B-mode ultrasound image of liver tissue at 60°C during water-bath experiment which represented coagulated structure, and ROI was selected manually from the images for each sample.
Table 1.
Textural features calculated from the normalized co-occurrence matrix.
Fig 3.
Changes of the B-mode ultrasound image texture features with temperature.
(a) Average Value±Std of the mean gray scale changes with temperature among the three GLH based texture features. (b) Average Value±Std of homogeneity in the direction of 45° changes with temperature among the sixteen GLCM based texture features. (c) Average Value±Std of correlation changes with temperature among the twelve GGCM based texture features. (d) Average Value±Std of hybrid entropy changes with temperature among the twelve GGCM based texture features.
Table 2.
Correlation coefficients (Average-Value ± Std) between the mean gray scale, standard deviation, and gray level entropy of tissue ultrasound B-mode images with different temperature.
Table 3.
Correlation coefficients (Average-Value ± Std) between gray level co-occurrence matrix (the angular second moment, contrast, entropy and correlation) at 4 directions (0°, 45°, 90°, 135°) of tissue ultrasound B-mode images with different temperature.
Table 4.
Correlation coefficients (Average-Value ± Std) between 12 texture parameters of gray level-gradient co-occurrence matrix of tissue ultrasound B-mode images with different temperature.
Table 5.
Correlation coefficients of five large texture feature parameters of ultrasound images with temperature and their mean P-value.