Pandey Anil Kumar, Dhiman Vishali, Sharma Akshima, ArunRaj Sreedharan Thankarajan, Baghel Vivek, Patel Chetan, Sharma Param Dev, Bal Chandra Sekhar, Kumar Rakesh
Department of Nuclear Medicine, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India; and
Department of Nuclear Medicine, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India; and.
J Nucl Med Technol. 2018 Sep;46(3):274-279. doi: 10.2967/jnmt.117.202929. Epub 2018 Mar 29.
Bone scintigraphy images might exceed the dynamic range (the ratio between the highest and the lowest displayable brightness) of the monitor. In such a case, a high-intensity area accompanied by loss of detail in other structures in the displayed image make the clinical interpretation challenging. We have investigated the role of an intensity-transformation (IT) function in enhancement of these types of images. Forty high-dynamic-range bone scintigraphy images were processed using an IT function. The IT function has 2 parameters: threshold and slope. With the threshold kept equal to the mean count of the image, the slope was varied from 1 to 20. A software program developed in-house was used to process the images. Twenty output images corresponding to one input image were visually inspected by 2 experienced nuclear medicine physicians to select images of diagnostic quality, and from their selection was determined the standardized slope that produced the maximum number of diagnostic images. The 2 physicians also scored the quality of the input and output images (at the standardized slope) on a scale of 1-5. The Student test was used to determine the significance of differences in mean score between the input and output images at an α significance level of 0.05. Application of the IT function with standardized parameters significantly improved the quality of high-dynamic-range bone scintigraphy images ( < 0.001, with α = 0.05). A slope of 8 maximized the number of diagnostic images. The IT function has a significant role in enhancing high-dynamic-range bone scintigraphy images.
骨闪烁扫描图像可能会超出显示器的动态范围（最高可显示亮度与最低可显示亮度之比）。在这种情况下，显示图像中出现高强度区域并伴有其他结构细节缺失，这给临床解读带来了挑战。我们研究了强度转换（IT）函数在增强这类图像方面的作用。使用IT函数对40幅高动态范围的骨闪烁扫描图像进行了处理。IT函数有2个参数：阈值和斜率。在阈值保持等于图像的平均计数的情况下，斜率从1变化到20。使用内部开发的软件程序对图像进行处理。由2名经验丰富的核医学医师对与一幅输入图像对应的20幅输出图像进行视觉检查，以选择具有诊断质量的图像，并根据他们的选择确定产生诊断图像数量最多的标准化斜率。这2名医师还对输入和输出图像（在标准化斜率下）的质量进行了1 - 5分的评分。使用Student检验来确定在α显著性水平为0.05时输入和输出图像平均得分差异的显著性。应用具有标准化参数的IT函数显著提高了高动态范围骨闪烁扫描图像的质量（P < 0.001，α = 0.05）。斜率为8时诊断图像数量最多。IT函数在增强高动态范围骨闪烁扫描图像方面具有重要作用。
