Abstract：
Purpose. The use of the Hough transform for angle detection is quite accurate for relatively wide slice thickness. However, the Hough transform fails to accurately detect the angle for thin slice thickness. This study proposes a method for automatically measuring the thickness of thin slices on images of a Catphan phantom.Methods. In the proposed method, the angle of the phantom\'s orientation was determined based on the relative coordinates of the four hole objects in the phantom. After the angles of the wires were determined, the profiles of pixel values across the wire objects were constructed. Finally, their full widths at half maximum (FWHMs) were determined and multiplied bytan23° to obtain the slice thicknesses of the images. The results of the proposed method were compared to a previous method, which used the Hough transform to obtain the phantom\'s orientation. We used slice thicknesses ranging from 0.8 mm to 5.0 mm, and phantom angles from 0° to 10°.Results. Our proposed method detected the angle of the phantom accurately for thin slices, whereas a previous method did not accurately detect the angle. The results of the slice thickness using this current method were slightly higher (within 7.9%) compared to the previous method. However, the results of the two methods did not differ significantly (p-value > 0.05). Using different angles, the current method detected all the angles more accurately. Again, the slice thicknesses were not significantly different from the previous method (p-value > 0.05).Conclusion. The proposed method for measuring the thickness of thin slices in an image of a Catphan phantom, based on the relative coordinates of the four hole objects in the phantom, outperformed a previous method based on the Hough transform.
摘要：
目的。对于相对较宽的切片厚度,将霍夫变换用于角度检测是相当准确的。然而,Hough变换无法准确检测薄片厚度的角度。这项研究提出了一种自动测量Catphan体模图像上薄片厚度的方法。方法。在提出的方法中，体模方向的角度是根据体模中四个孔物体的相对坐标确定的。电线的角度确定后，构造了整个导线对象的像素值的轮廓。最后,确定它们的半峰全宽（FWHM），并乘以tan23°以获得图像的切片厚度。将提出的方法的结果与以前的方法进行了比较，它使用霍夫变换来获得幻像的方向。我们使用的切片厚度范围从0.8毫米到5.0毫米，和从0°到10°的幻影角。结果。我们提出的方法准确地检测了薄切片的体模角度，而以前的方法没有准确检测角度。与先前的方法相比,使用该当前方法的切片厚度的结果略高(在7.9%内)。然而,两种方法的结果没有显着差异（p值>0.05）。使用不同的角度，当前的方法更准确地检测所有的角度。再一次,切片厚度与以前的方法没有显着差异（p值>0.05）。结论。提出的用于测量Catphan体模图像中薄片厚度的方法，根据幻像中四个孔物体的相对坐标，优于基于霍夫变换的先前方法。
