体素内不相干运动成像评价大鼠肝细胞癌的微血管生成

Intravoxel incoherent motion diffusion-weighted imaging applied in evaluating microcirculation of hepatocellular carcinoma in rat model

目的探讨应用体素内不相干运动成像(intravoxel incoherent motion diffusion weighted imaging,IVIM)评估肝细胞癌(hepatocellular carcinoma,HCC)的微血管密度(microvessel density,MVD)及微血管侵犯(microvascular invasion,MVI)的可行性。方法建立大鼠HCC模型,应用IVIM序列扫描大鼠,选取IVIM图像所对应的HCC病灶行病理学检查,测定其MVD,并判断病灶中是否发生MVI。采用Spearman相关分析评估表观弥散系数(apparent diffusion coefficient,ADC)、IVIM参数(D、D*及f)与HCC病灶MVD的相关性,采用独立样本t检验比较MVI阳性(+)组、阴性(–)组的ADC及IVIM参数。结果共纳入50个HCC病灶,ADC、D与MVD呈负相关(r=–0.406,P=0.003;r=–0.468,P=0.001),D*、f与MVD无统计学相关性(P=0.172、0.074);MVI(+)组和MVI(–)组的ADC及IVIM参数(D、D*及f)差异无统计学意义(P=0.393、0.395、0.221、0.550)。结论 ADC及IVIM参数(D)可用于评估HCC病灶MVD,但其评估MVI的能力受限。

Objective To assess the feasibility of intravoxel incoherent motion diffusion-weighted imaging （IVIM） in evaluating microvessel density （MVD） and microvascular invasion （MVI） of hepatocellular carcinoma （HCC）. Methods Rat models were established to be scanned by IVIM. HCC lesions corresponding to IVIM image were examined pathologically to get data of MVD and MVI. Spearman correlation analysis was used to compare the apparent diffusion coefficient （ADC）, D, D＊, andfwith MVD, independent samples t test was used to compare ADC, D, D＊, andf between MVI （＋） and MVI （-） groups. Results Fifty HCC lesions were included finally. ADC and D values both showed a negative correlation with MVD （r=-0.406, P=0.003; r=-0.468, P=0.001）, D＊ andfshowed no statistical correlation with MVD （P=0.172, 0.074, respectively）. The differences in ADC and all the IVIM parameters （D, D＊, and J） between MVI （＋） and MVI （-） HCCs were not statistically significant （P=0.393, 0.395, 0.221, 0.550）. Conclusion ADC and D can be used to evaluate MVD of HCC, but ADC and IVIM parameters were limited in evaluating MVI.