Background CT plays an important role in the opportunistic identification of hepatic steatosis. CT performance for steatosis detection has been inconsistent across various studies, and no clear guidelines on optimum thresholds have been established. Purpose To conduct a systematic review and meta-analysis to assess CT diagnostic accuracy in hepatic steatosis detection and to determine reliable cutoffs for the commonly mentioned measures in the literature. Materials and Methods A systematic search of the PubMed, Embase, and Scopus databases (English-language studies published from September 1977 to January 2024) was performed. Studies evaluating the diagnostic accuracy of noncontrast CT (NCCT), contrast-enhanced (CECT), and dual-energy CT (DECT) for hepatic steatosis detection were included. Reference standards included biopsy, MRI proton density fat fraction (PDFF), or NCCT. In several CECT and DECT studies, NCCT was used as the reference standard, necessitating subgroup analysis. Statistical analysis included a random-effects meta-analysis, assessment of heterogeneity with use of the I2 statistic, and meta-regression to explore potential sources of heterogeneity. When available, mean liver attenuation, liver-spleen attenuation difference, liver to spleen attenuation ratio, and the DECT-derived fat fraction for hepatic steatosis diagnosis were assessed. Results Forty-two studies (14 186 participants) were included. NCCT had a sensitivity and specificity of 72% and 88%, respectively, for steatosis (>5% fat at biopsy) detection and 82% and 94% for at least moderate steatosis (over 20%-33% fat at biopsy) detection. CECT had a sensitivity and specificity of 66% and 90% for steatosis detection and 68% and 93% for at least moderate steatosis detection. DECT had a sensitivity and specificity of 85% and 88% for steatosis detection. In the subgroup analysis, the sensitivity and specificity for detecting steatosis were 80% and 99% for CECT and 84% and 93% for DECT. There was heterogeneity among studies focusing on CECT and DECT. Liver attenuation less than 40-45 HU, liver-spleen attenuation difference less than -5 to 0 HU, and liver to spleen attenuation ratio less than 0.9-1 achieved high specificity for detection of at least moderate steatosis. Conclusion NCCT showed high performance for detection of at least moderate steatosis. © RSNA, 2024 Supplemental material is available for this article.

中文翻译：

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CT 检测肝脂肪变性的诊断准确性：系统评价和荟萃分析。


背景 CT 在肝脂肪变性的机会性识别中起着重要作用。在各种研究中，用于脂肪变性的 CT 检测性能不一致，并且尚未建立关于最佳阈值的明确指南。目的 进行系统评价和荟萃分析，以评估肝脂肪变性检测的 CT 诊断准确性，并确定文献中常用措施的可靠临界值。材料和方法 对 PubMed、Embase 和 Scopus 数据库（1977 年 9 月至 2024 年 1 月发表的英语研究）进行了系统检索。纳入了评估非增强 CT （NCCT） 、对比增强 （CECT） 和双能 CT （DECT） 检测肝脂肪变性诊断准确性的研究。参考标准包括活检、MRI 质子密度脂肪分数 （PDFF） 或 NCCT。在几项 CECT 和 DECT 研究中，NCCT 被用作参考标准，需要进行亚组分析。统计分析包括随机效应荟萃分析、使用 I2 统计量评估异质性以及荟萃回归以探索异质性的潜在来源。如果可用，评估平均肝脏衰减、肝脾衰减差异、肝脾衰减比以及 DECT 衍生的脂肪分数用于肝脂肪变性诊断。结果 共纳入 42 项研究 （14 186 名研究对象）。NCCT 对脂肪变性 （活检时脂肪百分比为 3E5%） 检测的敏感性和特异性分别为 72% 和 88%，对至少中度脂肪变性 （活检时脂肪含量超过 20%-33%） 的检测敏感性和特异性分别为 82% 和 94%。CECT 对脂肪变性检测的敏感性和特异性分别为 66% 和 90%，对至少中度脂肪变性检测的敏感性和特异性分别为 68% 和 93%。 DECT 对脂肪变性检测的敏感性和特异性分别为 85% 和 88%。在亚组分析中，CECT 检测脂肪变性的敏感性和特异性分别为 80% 和 99%，DECT 为 84% 和 93%。专注于 CECT 和 DECT 的研究之间存在异质性。肝脏衰减小于 40-45 胡，肝脾衰减差小于 -5 至 0 胡，肝脾衰减比小于 0.9-1 对检测至少中度脂肪变性具有高特异性。结论 NCCT 对至少中度脂肪变性的检测性能较高。© RSNA，2024 年本文提供补充材料。