Background: To date, there are inconsistent data about relationships between diffusion-weighted imaging (DWI) and tumor grading/microvascular invasion (MVI) in hepatocellular carcinoma (HCC). Our purpose was to systematize the reported results regarding the role of DWI in prediction of tumor grading/MVI in HCC. Method: MEDLINE library, Scopus, and Embase data bases were screened up to December 2019. Overall, 29 studies with 2,715 tumors were included into the analysis. There were 20 studies regarding DWI and tumor grading, 8 studies about DWI and MVI, and 1 study investigated DWI, tumor grading, and MVI in HCC. Results: In 21 studies (1,799 tumors), mean apparent diffusion coefficient (ADC) values (ADC_mean) were used for distinguishing HCCs. ADC_mean of G1–3 lesions overlapped significantly. In 4 studies (461 lesions), minimum ADC (ADC_min) was used. ADC_min values in G1/2 lesions were over 0.80 × 10⁻³ mm²/s and in G3 tumors below 0.80 × 10⁻³ mm²/s. In 4 studies (241 tumors), true diffusion (D) was reported. A significant overlapping of D values between G1, G2, and G3 groups was found. ADC_mean and MVI were analyzed in 9 studies (1,059 HCCs). ADC_mean values of MIV+/MVI− lesions overlapped significantly. ADC_min was used in 4 studies (672 lesions). ADC_min values of MVI+ tumors were in the area under 1.00 × 10⁻³ mm²/s. In 3 studies (227 tumors), D was used. Also, D values of MVI+ lesions were predominantly in the area under 1.00 × 10⁻³ mm²/s. Conclusion: ADC_min reflects tumor grading, and ADC_min and D predict MVI in HCC. Therefore, these DWI parameters should be estimated for every HCC lesion for pretreatment tumor stratification. ADC_mean cannot predict tumor grading/MVI in HCC.
Liver Cancer

中文翻译：

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扩散加权成像反映肝细胞癌的肿瘤分级和微血管浸润

背景：迄今为止，关于肝细胞癌 (HCC) 中弥散加权成像 (DWI) 与肿瘤分级/微血管侵袭 (MVI) 之间关系的数据不一致。我们的目的是系统化关于 DWI 在预测 HCC 肿瘤分级/MVI 中的作用的报告结果。方法：筛选了截至 2019 年 12 月的 MEDLINE 库、Scopus 和 Embase 数据库。总体而言，分析纳入了 29 项研究，涉及 2,715 个肿瘤。有 20 项关于 DWI 和肿瘤分级的研究，8 项关于 DWI 和 MVI 的研究，1 项研究调查了 HCC 中的 DWI、肿瘤分级和 MVI。结果：在 21 项研究（1,799 个肿瘤）中，平均表观扩散系数 (ADC) 值 (ADC _mean ) 用于区分 HCC。ADCG1-3 病变的_{平均值显着重叠。}在 4 项研究（461 个病灶）中，使用了最小 ADC（ADC _min）。G1/2 病变中的ADC_{最小值超过 0.80 × 10} ^-3 mm ² /s，而 G3 肿瘤中的 ADC 最小值低于 0.80 × 10 ^-3 mm ² /s。在 4 项研究（241 个肿瘤）中，报告了真扩散（D）。发现 G1、G2 和 G3 组之间的D值有显着重叠。在 9 项研究（1,059 例 HCC）中分析了ADC_{平均值和 MVI。}MIV+/MVI-病灶的ADC_{平均值显着重叠。}ADC _min用于 4 项研究（672 个病灶）。ADC_最小值MVI+肿瘤的值在1.00×10 ^-3 mm ² /s以下的区域。在 3 项研究（227 个肿瘤）中，使用了D。另外， MVI+病灶的D值主要在1.00×10 ^-3 mm ² /s以下的区域。结论： ADC _min反映肿瘤分级，ADC _min和D预测 HCC 的 MVI。因此，应对每个 HCC 病灶估计这些 DWI 参数以进行预处理肿瘤分层。ADC_平均值无法预测 HCC 中的肿瘤分级/MVI。
肝癌