摘要
目的初探3.0 T MR扫描仪上健康青年人肝脏扩散张量成像(DTI)的可行性及特性。方法对30名健康青年自愿者行上腹部DTI序列扫描,其中男15名,女15名,平均年龄(24.9±2.1)岁。纳入标准:实验室检查肝功能正常,经MR常规序列检查排除占位性病变及弥漫性肝病。采用GE Signa 3.0 T HD超导型MRI扫描仪,8通道联合相控阵线圈,呼吸门控及ASSET技术,应用频率选择脂肪饱和。在6个正交方向施加扩散梯度,b值分别为300、500、800 s/mm2,层厚7 mm,层距1 mm,视野35 cm×35 cm,矩阵96×128,激励次数4,Phase fov为0.8。在ADW 4.4工作站上行后处理,重组出平均扩散系数(ADC)图、部分各向异性(FA)图及各向同性图,计算不同b值下肝脏右叶的ADC值、FA值。应用AAPM方法计算不同b值下图像SI及SNR。采用SPSS 13.0统计学软件,应用单因素方差分析比较不同b值下的ADC值、FA值、SI及SNR。应用独立变量t检验比较男女组间的ADC值及FA值。P<0.05认为差异有统计学意义。结果不同b值下,30名自愿者的ADC值、SI及SNR具有显著性差异,随b值升高,ADC值、SI及SNR降低;FA值不具有统计学差异。男性和女性之间,不同b值下的ADC值及FA值均不具有显著性差异。结论肝脏DTI扫描是可行的。肝脏实质FA值在不同b值下相对稳定,有望应用于肝脏微观结构及弥漫性肝病的评价。DTI序列对于肝脏疾病的研究及临床应用具有良好前景。合适的扫描参数及后处理方法对于保证数据的稳定性及实验的可重复性具有重要意义。
Objective To explore the feasibility and characteristics of DTI （ diffusion tensor imaging, DTI） of healthy young adults liver using 3.0 T MR. Methods 30 volunteers （ male 15 ; female 15） with a mean age of 24.9± 2.1 years were performed with a respiratory triggered echo planar imaging sequence on a 3.0 Tesla MRI （ GE signa 3.0 T HD echos- peed MRI） system using a eight channel phased array body upper coil. ASSET technology and frequency selective fat satu- ration were used. 6 diffusion directions, b value were 300 ,500, and 800 s/mrn2 respectively, slice thickness 7 mm, slice gap 1 mm, FOV 35 cm x35 cm, Matrix 96 x 128, NEX =4,Phase fov 0.8. Inclusion criteria ： liver function was normal under the laboratory tests, occupied lesions and diffuse liver disease were excluded with the conventional MR sequences. ADC, FA and isotropic maps were rebuilt on the advanced workstation 4.4. ADC value and FA value of right lobe were measured. SI and SNR were measured according to AAPM method. One way ANOVA was used to compare ADC value, FA value, SI and SNR of different b value. Independent samples T test was used to compare the ADC value and FA value be- tween male and female. P 〈 0.05 was taken as statistical significance. Results ADC value, SI, and SNR were significant different with different b value, FA value had no significant difference. As b value increased, ADC value, SI, and SNR decreased. No difference of ADC value and FA value were found between male and female. Conclusion It is feasible for Liver DTI. FA value of liver is stable with different b value, and can be used to evaluate the microstructure and diffuse dis- ease of liver; DTI sequence has good prospects in further research and clinical application for liver.
出处
《临床放射学杂志》
CSCD
北大核心
2013年第3期348-351,共4页
Journal of Clinical Radiology
关键词
肝脏
磁共振成像
扩散张量成像
Liver Magnetic resonance imaging Diffusion tensor imaging
