IVIM评价兔VX2肿瘤血管生成的实验性研究

Experimental Study of IVIM in Evaluating Angiogenesis of Rabbit VX2 Tumor

目的:探索肿瘤微血管密度(MVD)的无创性影像学成像指标,可快速、重复地量化肿瘤微血管状态。方法:40只新西兰大白兔随机分为1周组(10只)、2周组(10只)、3周组(10只)和4周组(10只)共4组,1周组在VX2肿瘤植入后7天、2周组分别在肿瘤植入后7天和14天、3周组分别在7天和21天、4周组分别在7天和28天均进行MRI扫描,以正常大腿肌肉组织作为对照,在最后一次MRI扫描后处死实验兔进行CD34免疫组化分析并进行半定量。分析各组间DWI和IVIM相关参数的差异以及这些参数与MVD指数之间的相关关系。结果:各组的D*值和f值与MVD计数之间均存在相关性(P均<0.05),而ADC值和D值与MVD计数间均无明显统计学相关性(P均>0.05)。结论:IVIM的D*值与f值可以量化肿瘤进展时期微血管的情况,在评价肿瘤方面具有很大的价值。

Purpose: To explore the noninvasive imaging indicators of tumor microvascular density, which can rapidly and repeatedly quantify tumor microvascular status. Methods: Step 1: Forty New Zealand white rabbits were divided into 4 groups randomly: 1-week group(n=10), 2-week group(n=10), 3-week group(n=10), 4-week group(n=10). Step 2: MRI scans were undergone after VX2 tumor implanted. Normal thigh muscle tissue was taken as control. Group 1: MRI scan was done on 7 days after VX2 tumor implanted. Group 2: MRI scan was done on 7 days and 14 days after VX2 tumor implanted. Group 3: MRI scan was done on 7 days and 21 days after VX2 tumor implanted. Group 4: MRI scan was done after 7 days and 28 days after VX2 tumor implanted. Step 3: After the final MRI scan, rabbits were sacrificed for CD34 immunohistochemical exam and semi-quantitative analysis was done.The differences of DWI and IVIM related parameters among groups and the correlation between these parameters and the MVD indexes were analyzed. Results: There was a correlation between D* value and f value and MVD count in each group(P<0.05), but there was no statistical significant correlation between ADC value and D value and MVD count(P>0.05). Conclusion: The D* value and f value of IVIM can quantify the condition of capillary during tumor progression and have great value in evaluating tumors.