3.0T磁共振扩散成像在甲状腺的成像分析

Analysis of the 3.0 T diffusion magnetic resonance imaging in the thyroid

目的探讨3.0 T磁共振扩散成像在甲状腺的成像技术方法和信号特点。方法分别取b值为0、300、500、700 s/mm2对24例志愿者甲状腺行扩散加权成像,对信号强度、信噪比及表观弥散系数(ADC)值进行分析。结果图像信号强度、信噪比及ADC值随b值增大而减低;b值分别为0、300、500、700 s/mm2时,信号强度分别为:50±21、30±14、24±11、20±8,F=41.25,P<0.05;信噪比分别为:49±21、44±17、32±13、29±12,F=15.07,P<0.05;b值分别为300、500、700 s/mm2时,ADC值分别为:(1 981±388)、(1 647±293)、(1 408±211)mm2/s,F=42.323,P<0.05。结论随着b值增加,图像信号强度、信噪比及ADC值逐渐减小,b值在0～300 s/mm2区间信号强度减低明显,b值在300～500 s/mm2区间信噪比减低明显;ADC值在300～700 s/mm2区间呈逐渐均匀性减小。

Objective To investigate techniques and the signal characteristic of diffusion weighted imaging （DWI） with 3.0 T MR in the thyroid. Methods The thyroid DWI of twenty-four volunteers with b value was 0, 300, 500, 700 s/mm2, the signal strength, the signal noise ratio （SNR）, and the apparent diffusion coefficient （ADC） values were analyzed. Results The signal strength, SNR, and ADC values declined with the b value increased. When the b value were 0,300, 500, 700 s/mm2, the signal strength were 50±21,30±14,24±11,20±8（F=41.25 ,P〈0.05）, and the SNR values were 49±21,44±17,32±16,29±12（F=15.07,P〈0.05）. When the b values were 300, 500, 700 s/mm2, the ADC values were 1 981±388, 1 647±293, 1 408±211mm2/s（F=42.323,P〈0.05）. Conclusion With the increase of the b value, the signal strength, the SNR, and the ADC values decline. The signal strength is reduced significantly within the b value range of 0-300 s/mm2,the SNR values decrease obviously within the b value range of 300-500 s/mm2, the ADC values are decreased gradually within the b value range of 300-700 s/mm2.