不同b值转移性淋巴结扩散成像研究

Study of MR Diffusion-weighted Imaging in Rabbit VX2 Metastatic Lymphadenopathy Models with Different b Values

目的:探讨不同b值下兔VX2转移淋巴结模型扩散成像ADC值的差异。方法:对20只新西兰兔VX2转移淋巴结模型及20只炎性淋巴结实验兔进行常规磁共振成像及扩散成像(b值分0～500s/mm2及0～1000s/mm2两组)。在常规图像基础上测量转移淋巴结及炎性淋巴结的平均弥散系数(ADC)。所有ADC结果以平均数±标准差表示,并进行统计学分析。所有淋巴结均经病理证实。结果:0～500s/mm2两个b值组良恶性淋巴结ADC值之间无统计学差异,而0～1000s/mm2组有统计学差异(t=-3.298,P=0.021)。结论:高b值能够更真实地反映病变内水分子扩散能力的变化。

Purpose： To evaluate the difference of ADC values in VX2 metastatic lymphadenopathy models with different b values. Methods： Conventional MRI and DWI images were obtained from 40 rabbits, which were divided into two groups as lymphadenitis model and metastaic lymph node model. ADC values of lymph nodes with different b values （including 0 - 500 s/mm2 and 0 - 1000 s/mm2） were measured. The results of all ADC values were expressed as the average ＋ standard deviation, and were compared （paired t - test） between different groups and different b values. All lymph nodes were confirmed by pathology. Results： When low b values （0- 500 s/ mm2） were used, there was no statistical difference between the average ADCs of benign and malignant lymph nodes. There was statistical difference between them when high b values（0- 1000s/mm2） were used（t = - 3. 298, P = 0.021） . Conclusion： Diffusion - weighted imaging can reveal water diffusion in lesions more accurate with high b value.