Park Hye Jung, Jung Seung Eun, Lee Young Joon, Cho Woo Il, Do Kyung Hyun, Kim Seung Hyup, Kim Ki Hwang
Department of Radiology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Korean J Radiol. 2009 Sep-Oct;10(5):490-5. doi: 10.3348/kjr.2009.10.5.490. Epub 2009 Aug 25.
To evaluate whether there is a relationship between subjective parameters determined by a reviewer (spatial resolution, low contrast resolution, and artifacts) and objective parameters (the CT number of water, noise, and image uniformity) in CT phantom image evaluations.
We reviewed the CT results of phantom image evaluations conducted by Korean Institute for Accreditation of Medical Image (KIAMI) from May 2007 to June 2007. We compared the objective parameters against the pass or fail groups for the subjective parameters. We also evaluated whether there is a relationship between the artifact types and the other subjective parameters.
The mean noise value was significantly higher in the fail groups for the subjective parameters compared to the pass groups (p = 0.006). Specifically, noise and low contrast resolution were found to have a statistically significant positive correlation (r = 0.183, p < 0.001). In the fail group for low contrast resolution, the failure due to artifacts was significantly higher than the pass group (p < 0.001). In contrast, no statistically significant differences were found for the mean CT number of water, noise, or image uniformity based on the types of artifacts.
Subjective CT image parameters evaluated by a reviewer correlate with objectively measured parameters, especially noise. Therefore, a stricter noise standard might be able to improve the subjective parameters results, such as low contrast resolution.
评估在CT体模图像评估中，由审阅者确定的主观参数（空间分辨率、低对比度分辨率和伪影）与客观参数（水的CT值、噪声和图像均匀性）之间是否存在关联。
我们回顾了韩国医学影像认证机构（KIAMI）在2007年5月至2007年6月期间进行的体模图像评估的CT结果。我们将客观参数与主观参数的通过或未通过组进行了比较。我们还评估了伪影类型与其他主观参数之间是否存在关联。
与通过组相比，主观参数未通过组的平均噪声值显著更高（p = 0.006）。具体而言，发现噪声与低对比度分辨率具有统计学上显著的正相关（r = 0.183，p < 0.001）。在低对比度分辨率未通过组中，因伪影导致的未通过情况显著高于通过组（p < 0.001）。相比之下，基于伪影类型，水的平均CT值、噪声或图像均匀性未发现统计学上的显著差异。
审阅者评估的主观CT图像参数与客观测量参数相关，尤其是噪声。因此，更严格的噪声标准可能能够改善主观参数结果，如低对比度分辨率。
