应用多鼠磁共振检查评价放射性软组织损伤的可行性

Feasibility of evaluation of radiation-induced soft tissue injury by multi-mouse MRI

目的:探讨应用3. 0T磁共振(MRI)同时检查多只小鼠评价放射性软组织损伤的可行性。方法:20只8周龄雄性C57BL/6小鼠随机分成对照组和照射组,每组均为10只。照射组应用6 MV X射线,单次照射小鼠右后肢30 Gy,对照组予以假照射。分别于照射前和照射后第7天进行3. 0T MRI检查,每次同时检查5～6只小鼠。比较两组小鼠右后肢大腿肌肉的表观弥散系数(ADC)值和纵向弛豫时间(T1)值。结果:小鼠后肢MRI图像质量好,对比度高。照射前两组小鼠右后肢大腿肌肉的ADC值和T1值的差异均无统计学意义(P> 0. 05)。照射后第7天照射组小鼠两侧后肢大腿肌肉的ADC值和T1值的差异亦均无统计学意义(P> 0. 05)。照射后第7天对照组和照射组小鼠右后肢大腿肌肉的ADC值分别为(1. 34±0. 09)×10^(-3)mm^2/s和(1. 45±0. 11)×10^(-3)mm^2/s,差异有统计学意义(t=2. 473,P=0. 024); T1值分别为(1 394. 9±70. 8) ms和(1 514. 9±110. 5) ms,差异有统计学意义(t=2. 890,P=0. 010)。结论:3. 0T MRI同时检查多只小鼠应用于评价小鼠放射性软组织损伤简单、可行。

Objective:To investigate the feasibility of evaluation of radiation-induced soft tissue injuries in multiple mice by application of 3.0T magnetic resonance imaging(MRI).Methods:Twenty eight-week-old male C57BL/6 mice were randomly divided into control group and irradiation group,10 mice in each group.The right hind limb of mouse in the irradiation group was irradiated 30 Gy with 6 MV X-ray in a single shot and the animals in the control group was irradiated with sham.3.0T MRI examination was performed before irradiation and the 7th day after irradiation,and 5-6 mice were simultaneously examined at a time.The differences of the apparent diffusion coefficient(ADC)value and the longitudinal relaxation time(T1)value of the right hind thigh muscles between the two groups of mice were compared.Results:MRI images of hind limbs in mice were of good quality and high contrast.There was no significant difference in ADC value and T1 value of the right hind thigh muscles between the two groups before irradiation(P >0.05).There was also no significant difference in ADC value and T1 value of the thigh muscles between the two hind limbs of the irradiated group mice on the 7th day after irradiation(P >0.05).On the 7th day after irradiation,the ADC values of the right hind thigh muscle of the control group and the irradiated group were(1.34±0.09)×10^-3mm^2/s and(1.45±0.11)×10^-3mm^2/s,respectively.The later was significantly higher than the former(t=2.473,P=0.023).In addition,the T1 values of the radiated group[(1 514.9±110.5)ms]was significantly higher than those of the control group[(1 394.9±70.8)ms,t=2.890,P=0.010].Conclusion:It is a simple and feasible method to use 3.0T MRI to simultaneously examine multiple mice for evaluating radiation-induced soft tissue injuries in mice.