摘要
目的探讨正常前列腺3.0T磁共振扩散加成像(DWI)的影像表现,为合理选择扩散敏感系数(b值)提供依据。方法选取20名健康志愿者,每名志愿者行3次前列腺DWI扫描,b值分别取600、800、1000 s/mm^2,其他参数均一样。测量3种b值DWI图像中前列腺中央带和外周带的信号强度、背景信号强度标准差、表观扩散系数(ADC),计算图像信噪比(SNR)和对比噪声比(CNR),并对图像质量进行主观评分。结果b值为600、800、1000 s/mm^2时,SNR分别为(18.36±1.75)、(14.63±2.32)、(11.83±1.65),CNR分别为(0.55±0.14)、(0.47±0.11)、(0.39±0.90),3组间比较SNR和CNR的差异均具有统计学意义(P<0.05)。b值为600 s/mm^2时,前列腺外周带和中央带的ADC值分别为(2.07±0.26)×10^(-3)mm^2/s和(2.01±0.15)×10^(-3)mm^2/s,差异不具有统计学意义(P>0.05);b值为800 s/mm^2时,外周带和中央带的ADC值分别为(1.80±0.22)×10^(-3)mm^2/s和(1.65±0.24)×10^(-3)mm^2/s,差异具有统计学意义(P<0.05);b值为1000 s/mm^2时,外周带和中央带的ADC值分别(1.54±0.14)×10^(-3)mm^2/s和(1.31±0.19)×10-3 mm^2/s,差异具有统计学意义(P<0.05)。3种b值的图像质量评分分别为(3.4±0.68)、(3.05±0.69)和(2.75±0.91),3组间比较差异具有统计学意义(P<0.05)。结论利用3.0T磁共振对前列腺进行DWI扫描时,选择b值为800 s/mm^2较为适当,可在保证图像质量的前提下更好地反映水分子的扩散特征。
Objective To investigate the features of normal prostates in 3.0T DW MR（Diffusion-Weighted Magnetic Resonance） images so as to provide a basis for selection of the optimal b-value.Methods Three b-values（b=600,800,1000 s/mm^2） were applied respectively in 3.0T DW MR imaging of twenty normal prostates.Then,the signal intensity,standard deviation of the background signal intensity and apparent diffusion coefficient（ADC） values were measured in DWI of the central zone and peripheral zone of prostates.The signal-noise ratio（SNR） and contrast-noise ratio（CNR） were computed.And the quality of MR images were evaluated.Results When b-value was 600,800 and 1000s/mm^2,the SNR was（18.36±1.75）,（14.63±2.32） and（11.83±1.65） and the CNR was（0.55±0.14）,（0.47±0.11） and（0.39±0.90）respectively.There were statistically significant difference in SNR and CNR between different b-values（P〈0.05）.When b-value was 600 s/mm^2,the ADC values acquired in MR imaging of the peripheral zone and central zone of prostates were（2.07±0.26）×10^-3 mm^2/s and（2.01±0.15）×10^-3 mm^2/s respectively without statistically significant differences（P〈0.05）.When b-value was 800 and 1000 s/mm^2,the ADC values of the peripheral zone and central zone of prostates were（1.80±0.22）×10^-3mm^2/s and（1.65±0.24）×10^-3 mm^2/s,（1.54±0.14）×10^-3 mm^2/s and（1.31±0.19）×10^-3 mm^2/s respectively with statistically significant differences（P〈0.05）.The quality of MR images at three b-values（600,800,1000 s/mm^2） were evaluated as（3.4±0.68）,（3.05±0.69） and（2.75±0.91） respectively with statistically significant differences（P〈0.05）.Conclusion The optimal b-value in 3.0T DW MRI of prostates was800 s/mm^2,which can display the diffusion of water molecules and meanwhile ensure the quality of images.
出处
《中国医疗设备》
2015年第2期59-62,共4页
China Medical Devices
