中文摘要：

目的探讨3．0T磁共振弥散加权成像（diffusionweightedimaging，DWI）对CT一26结肠癌荷瘤鼠模型的应用价值。方法40只BALB／c小鼠右侧腋部皮下接种0．2mLCT-26结肠癌细胞（5×10-6个／mL，2W后行MR检查，测量肿瘤体积并观察T1WI、T2WI信号表现，测量DWI图像上肿瘤中心实性部分、肿瘤边缘部分和瘤周正常肌肉组织感兴趣区内的ADC值及信号强度。结果MRI测量肿瘤体积与病理测量结果差异无统计学意义（P〉0．05），且明显正相关（r=0．964）。在b值为（0，1000a／mm2）时，DWI图像多表现为明显高信号，信噪比与12Ⅵ相比差异有统计学意义（P〈0．05）。DWI和T2WI上肿瘤组织中心实性部分和肿瘤边缘部分的信号强度、ADC值间均无统计学差异（P〉0．05），但与瘤周正常肌肉组织信号强度、ADC值间均有统计学差异（P〈0．05）。结论DWI能直观的显示肿瘤病灶。通过ADC值的定量能准确无创的对活体肿瘤进行评价。

英文摘要：

Objective To explore the value of 3.0 T MR diffusion weighted imaging on the mice with CT - 26 transplanted tumors. Methods Forty BABL/c mice （20 male and 20 female） were transplanted with 0. 2 mL CT - 26 coloreetal cancer cells （ 5 × 106 ceUs/mL） subeutaneonsly in the axillary region. MR/was used after two weeks to test the volume of tumor, the signal features of T1WI and T2WI, the signal intensity and ADC value in the DWI of the solid part in the eenter of tumor, edge part of tumor and the normal musculature surrounding tumor. Results There was distinctly positive correlation in terms of tumor volume between the results measured by MR/and by pathological survey （ r =0. 964）, but with no statistical significance （P 〉0.05）. When b = （0, 1 000 s/ mm2 ）, DWI were mostly observed as obvious high signal intensity, the SNR of which was with statistical significance in the comparison with that of T2WI. As for the signal intensity and ADC value showed by DWI and T2WI, there was no statistical signifieance between the part of solid tumor center and the edge of tumor （ P 〉 0. 05 ）, but was statistically different compared with those of the normal mus- culature surrounding tumor （P 〈 0. 05）. Conclusion By DWI, the tumor can be observed directly. It ean also be evaluated accu- rately and non - invasively by the measurement of ADC value.