Purpose

To evaluate feasibility of computer tomography texture analysis (CTTA) at different energy level using dual-energy spectral detector CT for liver fibrosis.

Materials and methods

Eighty-seven patients who underwent a spectral CT examination and had a reference standard of liver fibrosis (histopathologic findings, n = 61, or clinical findings for normal, n = 26) were included. Mean gray-level intensity, mean number of positive pixels (MPP), entropy, skewness, and kurtosis using commercially available software (TexRAD) were compared at different energy levels. Optimal CTTA parameter cutoffs to diagnose liver fibrosis were evaluated. CTTA parameters at different energy levels correlated with liver fibrosis. The association of CTTA parameters with energy level was evaluated.

Results

Mean gray-level intensity, skewness, kurtosis, and entropy showed significant differences between patients with and without clinically significant hepatic fibrosis (P < 0.05). Mean gray-level intensity at 50 keV was significantly positively correlated with liver fibrosis (ρ = 0.502, P < 0.001). To diagnose stages F2–F4, entropy and mean gray-level intensity at low keV level showed the largest area under the curve (AUC; 0.79 and 0.79). Estimated marginal means (EMMs) of mean gray-level intensity showed prominent differences at low energy levels.

Conclusion

CTTA parameters from different keV levels demonstrated meaningful accuracy for diagnosis of liver fibrosis or clinically significant hepatic fibrosis.

中文翻译：

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使用双能谱探测器计算机断层扫描技术对肝纤维化进行计算机断层扫描纹理分析的可行性。

目的

为了评估使用双能谱探测器CT在不同能量水平下进行计算机断层扫描纹理分析（CTTA）进行肝纤维化的可行性。

材料和方法

包括八十七名接受了频谱CT检查并具有肝纤维化参考标准的患者（组织病理学发现，n  = 61，或正常临床发现，n  = 26）。使用市售软件（TexRAD）在不同能级下比较了平均灰度强度，正像素平均数（MPP），熵，偏度和峰度。评估了诊断肝纤维化的最佳CTTA参数临界值。不同能量水平的CTTA参数与肝纤维化相关。评估了CTTA参数与能量水平的关联。

结果

在有和没有临床上明显肝纤维化的患者之间，平均灰度强度，偏度，峰度和熵显示出显着差异（P  <0.05）。50 keV时的平均灰度强度与肝纤维化显着正相关（ρ  = 0.502，P  <0.001）。为了诊断阶段F2-F4，在低keV水平下，熵和平均灰度强度显示曲线下面积最大（AUC； 0.79和0.79）。在低能级下，估计的平均灰度强度的边际均值（EMM）显示出显着差异。

结论

来自不同keV水平的CTTA参数显示出对诊断肝纤维化或临床上重要的肝纤维化有意义的准确性。