Supplementary Material for: Quality Assessment of Ultrasound and Magnetic Resonance Imaging for Hepatocellular Carcinoma Surveillance: A Systematic Review and Meta-Analysis

<b><i>Introduction:</i></b> To achieve early detection and curative treatment options, surveillance imaging for hepatocellular carcinoma (HCC) must remain of quality and without substantial limitations in liver visualization. However, the prevalence of limited liver visualization during HCC surveillance imaging has not been systematically assessed. Utilizing a systematic review and meta-analytic approach, we aimed to determine the prevalence of limited liver visualization during HCC surveillance imaging. <b><i>Methods:</i></b> MEDLINE and Embase electronic databases were searched to identify published data on liver visualization limitations of HCC surveillance imaging. An analysis of proportions was pooled using a generalized linear mixed model with Clopper-Pearson intervals. Risk factors were analysed using a generalized mixed model with a logit link and inverse variance weightage. <b><i>Results:</i></b> Of 683 records, 10 studies (7,131 patients) met inclusion criteria. Seven studies provided data on liver visualization limitations on ultrasound (US) surveillance exams: prevalence of limited liver visualization was 48.9% (95% CI: 23.5–74.9%) in the overall analysis and 59.2% (95% CI: 24.2–86.9%) in a sensitivity analysis for cirrhotic patients. Meta-regression determined that non-alcoholic fatty liver disease was associated with limited liver visualization on US. Four studies provided data for liver visualization limitations in abbreviated magnetic resonance imaging (aMRI), with inadequate visualization ranging from 5.8% to 19.0%. One study provided data for complete MRI and none for computed tomography. <b><i>Conclusion:</i></b> A substantial proportion of US exams performed for HCC surveillance provide limited liver visualization, especially in cirrhosis, which may hinder detection of small observations. Alternative surveillance strategies including aMRI may be appropriate for patients with limited US visualization.

<b><i>引言：</i></b> 为实现肝细胞癌（hepatocellular carcinoma, HCC）的早期检出与根治性治疗，其随访监测影像学检查必须保证成像质量合格且不存在肝脏显影的显著局限。然而，目前尚未有研究对肝细胞癌随访监测影像学检查中肝脏显影受限的发生率开展系统评估。本研究采用系统评价与荟萃分析方法，旨在明确肝细胞癌随访监测影像学检查中肝脏显影受限的发生率。<b><i>方法：</i></b> 检索MEDLINE数据库与Embase数据库，筛选获取有关肝细胞癌随访监测影像学检查肝脏显影受限的已发表研究数据。采用广义线性混合模型结合Clopper-Pearson置信区间进行合并率分析；采用带有logit连接函数与逆方差权重的广义混合模型对危险因素进行分析。<b><i>结果：</i></b> 在检索得到的683条文献记录中，共计10项研究（纳入7131名患者）符合研究纳入标准。其中7项研究提供了超声（ultrasound, US）监测检查的肝脏显影受限相关数据：总体分析显示肝脏显影受限发生率为48.9%（95%置信区间：23.5%~74.9%）；针对肝硬化患者的敏感性亚组分析显示，该发生率为59.2%（95%置信区间：24.2%~86.9%）。Meta回归分析表明，非酒精性脂肪性肝病与超声检查下的肝脏显影受限存在显著关联。4项研究提供了简化版磁共振成像（abbreviated magnetic resonance imaging, aMRI）的肝脏显影受限数据，其显影不足率介于5.8%~19.0%之间。另有1项研究提供了完整磁共振成像的相关数据，未检索到计算机断层扫描（computed tomography, CT）的相关研究数据。<b><i>结论：</i></b> 相当比例的肝细胞癌随访监测超声检查存在肝脏显影受限的情况，在肝硬化患者中尤为显著，这可能会阻碍微小病变的检出。对于超声检查显影受限的患者，采用简化版磁共振成像等替代监测方案或许是合理的选择。