摘要
目的:探讨扩散敏感因子(b值)和层厚对背景信号抑制扩散加权成像(diffusion weighted imaging with background suppression,DWIBS)序列腰骶丛神经成像质量的影响,优化成像参数。方法:随机选取24名健康志愿者在3.0T MRI上行DWIBS序列腰骶丛神经成像,参数选择b=600、800、1 000 s/mm^2,层厚=2、3、4 mm,对所得9组图像进行客观和主观评价。采用Kolmogorov-Smirnov检验对数据行正态检验;采用方差分析及LSD-t检验对不同b值及不同层厚下的信噪比(signal noise ratio,SNR)、对比噪声比(contrast to noise ratio,CNR)进行检验;采用Friedman M检验及q(SNK)检验评价主观图像质量。结果:(1)客观评价:相同b值不同层厚条件下SNR神经之间无统计学差异(P>0.05),CNR之间也无统计学差异(P>0.05)。相同层厚不同b值条件下SNR神经之间有统计学差异(P<0.05),CNR之间无统计学差异(P>0.05),但随着b值的增加CNR有降低的趋势。(2)主观评价:两两比较,当b=600 s/mm^2时,层厚为2 mm时的主观评分与层厚为3、4 mm时的主观评分之间差异均有统计学意义(P<0.05);当b=800、1 000 s/mm^2时,层厚为2、3、4 mm时的主观评分之间差异均有统计学意义(P<0.05)。结论:DWIBS序列用于3.0T MRI腰骶丛神经成像时,参数选择b=800 s/mm^2、层厚=3 mm时,可以得到理想的腰骶丛神经图像。
Objective To explore the effect of different proliferation-sensitive factor b values(b-value) and thicknesses on diffusion weighted imaging with background suppression(DWIBS) image quality, and obtain the optimal scan parameters of DWIBS in lumbosacral plexus imaging. Methods Totally 24 adult volunteers underwent DWIBS with 3.0 T MRI scanner, and the values of b taken as 600, 800 and 1 000 s/mm^2 and the thickness as 2, 3 and 4 mm. There were 9 sets of images acquired went through subjective and objective evaluations. The normality test of the data was executed with Kolmogorov-Smirnov;One-way-ANOVA and LSD-t tests were used to compare the signal noise ratio(SNR) and contrast to noise ratio(CNR)among different b values and thicknesses;subjective image quality was evaluated by Friedman M test and q(SNK) test. Results There were no significant differences of SNR and CNR under the combination of different thickness and the same b value(P >0.05). Statistical differences were found in SNR between conditions of the same thickness and different b values(P<0.05). There were no significant differences of CNR among the groups of the same b value and different thicknesses(P>0.05),while there was an increasing trend with the increase of thickness. The differences of the subjective image quality ratings between the two image sequences of DWIBS were statistically significant(P<0.05). For subjective scoring of image quality,when b=600 s/mm^2, there were significant differences between the thicknesses of 2 and 3, 4 mm(P<0.05);when b=800 s/mm^2 and b=1 000 s/mm^2, the thicknesses of 2, 3, 4 mm subjective ratings were statistically different(P<0.05). Conclusion DWIBS gains satisfactory 3.0 T MRI image for lumbosacral plexus in case b=800 s/mm^2 and thickness was 3 mm.
作者
赵洪波
陈芳妮
邹薇薇
刘士远
ZHAO Hong-bo;CHEN Fang-ni;ZOU Wei-wei;LIU Shi-yuan(Department of Radiology and Nuclear Medicine,Changzheng Hospital,Naval Medical University,Shanghai 200003,China)
出处
《医疗卫生装备》
CAS
2019年第9期33-36,54,共5页
Chinese Medical Equipment Journal
基金
国家自然科学基金青年项目(81501465)
关键词
MRI
背景信号抑制扩散加权成像
腰骶丛神经
B值
信噪比
对比噪声比
参数优化
magnetic resonance imaging
diffusion weighted imaging with background suppression
lumbosacral plexus
b value
signal noise ratio
contrast to noise ratio
parameter optimization
