Hsieh Scott S, Holmes Iii David R, Carter Rickey E, Tan Nelly, Inoue Akitoshi, Yalon Mariana, Gong Hao, Sudhir Pillai Parvathy, Leng Shuai, Yu Lifeng, Fidler Jeff L, Cook David A, McCollough Cynthia H, Fletcher Joel G
Mayo Clinic, Rochester, USA.
Shiga University of Medical Science, Ōtsu, Japan.
Abdom Radiol (NY). 2025 Feb;50(2):668-676. doi: 10.1007/s00261-024-04520-4. Epub 2024 Aug 20.
Subtle liver metastases may be missed in contrast enhanced CT imaging. We determined the impact of lesion location and conspicuity on metastasis detection using data from a prior reader study.
In the prior reader study, 25 radiologists examined 40 CT exams each and circumscribed all suspected hepatic metastases. CT exams were chosen to include a total of 91 visually challenging metastases. The detectability of a metastasis was defined as the fraction of radiologists that circumscribed it. A conspicuity index was calculated for each metastasis by multiplying metastasis diameter with its contrast, defined as the difference between the average of a circular region within the metastasis and the average of the surrounding circular region of liver parenchyma. The effects of distance from liver edge and of conspicuity index on metastasis detectability were measured using multivariable linear regression.
The median metastasis was 1.4 cm from the edge (interquartile range [IQR], 0.9-2.1 cm). Its diameter was 1.2 cm (IQR, 0.9-1.8 cm), and its contrast was 38 HU (IQR, 23-68 HU). An increase of one standard deviation in conspicuity index was associated with a 6.9% increase in detectability (p = 0.008), whereas an increase of one standard deviation in distance from the liver edge was associated with a 5.5% increase in detectability (p = 0.03).
Peripheral liver metastases were missed more frequently than central liver metastases, with this effect depending on metastasis size and contrast.
在对比增强CT成像中，可能会遗漏微小的肝转移灶。我们使用先前读者研究的数据，确定了病变位置和清晰度对转移灶检测的影响。
在先前的读者研究中，25名放射科医生每人检查40例CT检查，并圈出所有疑似肝转移灶。选择的CT检查共包括91个视觉上具有挑战性的转移灶。转移灶的可检测性定义为圈出它的放射科医生的比例。通过将转移灶直径与其对比度相乘来计算每个转移灶的清晰度指数，对比度定义为转移灶内圆形区域的平均值与肝实质周围圆形区域的平均值之差。使用多变量线性回归测量距肝边缘的距离和清晰度指数对转移灶可检测性的影响。
转移灶的中位数距离边缘1.4 cm（四分位间距[IQR]，0.9 - 2.1 cm）。其直径为1.2 cm（IQR，0.9 - 1.8 cm），对比度为38 HU（IQR，23 - 68 HU）。清晰度指数增加一个标准差与可检测性增加6.9%相关（p = 0.008），而距肝边缘距离增加一个标准差与可检测性增加5.5%相关（p = 0.03）。
肝外周转移灶比肝中央转移灶更容易被遗漏，这种影响取决于转移灶的大小和对比度。
