体素内不相干运动弥散加权成像与弥散加权成像鉴别诊断甲状腺良恶性结节：Meta分析

目的 采用Meta分析方法评价体素内不相干运动弥散加权成像（IVIM-DWI）及弥散加权成像（DWI）鉴别诊断甲状腺良恶性结节的效能。方法 检索Cochrane Library、Embase、PubMed、中国知网、万方医学网及中国生物医学文献数据库，根据标准筛选建库至2020年5月IVIM-DWI及DWI参数鉴别诊断甲状腺良恶性结节相关文献，提取相关资料，以Stata 12.0和Meta-disc 1.4软件进行Meta分析。结果 纳入文献17篇文献，包括12篇英文、5篇中文文献，787个良性、634个恶性共1 421个甲状腺结节；根据真实扩散系数（D）值诊断的合并敏感度及特异度、阳性似然比及阴性似然比分别为0.85（0.71，0.92）、0.90（0.85，0.94）、8.77（5.29，14.55）及0.17（0.09，0.34）；表观扩散系数（ADC）的相应合并值分别为0.88（0.85，0.91）、0.90（0.85，0.94）、8.86（5.66，13.88）及0.13（0.10，0.16），其AUC与D值差异无统计学意义（Z=-0.299，P=0.385）。异质性检验结果显示文献中ADC的合并特异度及D值的合并敏感度存在异质性。ADC值及D值诊断甲状腺良恶性结节无明显阈值效应（r=-0.113、-0.145，P=0.676、0.784）。分析研究类型、设备场强、b值、感兴趣区等因素，均未发现异质性的明确来源。结论 以D值及ADC值诊断甲状腺良恶性结节的效能相当，但IVIM-DWI参数可提供更多相关信息，且结果稳定性、可重复性更佳。

Differential diagnosis of benign and malignant thyroid nodules with intravoxel incoherent motion diffusion-weighted imaging and diffusion-weighted imaging: Meta-analysis

Objective To evaluate the efficacy of intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) and diffusion-weighted imaging (DWI) for distinguishing malignant and benign thyroid nodules with meta-analysis. Methods Literature regarding IVIM-DWI and DWI parameters for differentiating benign and malignant thyroid nodules were searched in Cochrane Library, Embase, PubMed, CNKI, Wanfang Med Online and Chinese Biomedical Literature Database from the establishment of database to May 2020 and then screened according to the criteria, and the related information were extracted. Analysis were performed using Stata 12.0 and Meta-disc 1.4 software. Results A total of 17 articles, i.e. 12 English and 5 Chinese articles were included, reporting 1 421 thyroid nodules( 787 benign and 634 malignant ones). The summary sensitivity, specificity, positive likelihood ratio (PLR) and negative likelihood ratio (NLR) of D was 0.85 (0.71, 0.92), 0.90 (0.85, 0.94), 8.77 (5.29, 14.55) and 0.17 (0.09, 0.34), respectively, while of apparent diffusion coefficient (ADC) was 0.88 (0.85, 0.91), 0.90 (0.85, 0.94), 8.86 (5.66, 13.88) and 0.13 (0.10, 0.16), respectively. There was no significant difference (Z=-0.299, P=0.385) of AUC between D (0.93 ) and ADC values (0.92 ). Heterogeneity analysis showed that there were heterogeneity of the summary specificity of ADC and the summary sensitivity of D values. No significant threshold effect of ADC (r=-0.113, P=0.676) nor D value (r=-0.145, P=0.784) was detected for distinguishing benign and malignant thyroid nodules. Heterogeneity analysis of ADC and D values detected no clear source of heterogeneity with meta-analysis among study types, device field intensities, b values, ROIs nor other factors. Conclusion D and ADC values showed similar diagnostic performances for identifying malignant and benign thyroid nodules. However, the parameters of IVIM-DWI could provide further information of thyroid nodules and more stable and repeatable results.