Honda E, Domon M, Sasaki T
Department of Dental Radiology and Radiation Research, Faculty of Dentistry, Tokyo Medical and Dental University, Japan.
Invest Radiol. 1991 Oct;26(10):894-901. doi: 10.1097/00004424-199110000-00012.
A method for measuring the fractal dimension of radiographic images was devised by the modified pixel dilation (PD) method, and its accuracy was examined by two types of image analyzers: one controlled by a minicomputer and based on the hexagonal array of the pixels, and the other controlled by a personal computer and based on the square array of the pixels. It was shown that the fractal dimensions measured by using the image analyzers for three curves (straight line, Koch curve, and Sierpinski gasket) were deviated by less than 2.1% from the theoretical dimension. The time required for the measurements fell within 10 seconds by the minicomputer-controlled image analyzer, and within 12 minutes by the personal computer-controlled image analyzer, which contrasts to the 30 minutes or more required for measuring fractal dimensions by other available methods. Analysis of the ductal patterns in sialograms by this method indicated that the fractal dimensions were significantly different between normal parotids and parotids with Sjögren syndrome. The modified PD method can be used for measuring the fractal dimension of ductal patterns in sialograms. The measurements may serve as numerical gradings of the progression of disease.
通过改进的像素扩张（PD）方法设计了一种测量放射图像分形维数的方法，并使用两种图像分析仪对其准确性进行了检验：一种由小型计算机控制，基于像素的六边形阵列；另一种由个人计算机控制，基于像素的正方形阵列。结果表明，使用图像分析仪测量三条曲线（直线、科赫曲线和谢尔宾斯基垫圈）的分形维数与理论维数的偏差小于2.1%。小型计算机控制的图像分析仪测量所需时间在10秒以内，个人计算机控制的图像分析仪测量所需时间在12分钟以内，这与其他现有方法测量分形维数所需的30分钟或更长时间形成对比。用该方法分析涎腺造影片中的导管形态表明，正常腮腺和干燥综合征腮腺的分形维数有显著差异。改进的PD方法可用于测量涎腺造影片中导管形态的分形维数。这些测量结果可作为疾病进展的数值分级。
