采用压缩感知技术的Grasp-Vibe序列在肝脏MRI增强检查应用价值

The application value of Grasp-Vibe sequence using compressed sensing technology in liver MR enhanced examination

目的比较Grasp-vibe序列和CDT-vibe、Dixon-vibe组合序列在肝脏MRI增强中的图像质量,分析Grasp-vibe序列的应用价值。方法选取因体检发现肝脏占位、CA199增高等原因来我院检查的患者共70例。行Grasp-vibe序列和CDT-vibe、Dixon-vibe组合序列扫描方式的患者各35例。采用5分制法,评价两种模式下的动脉晚期、门静脉期、延迟期图像的主观评分以及所有序列的运动伪影得分。测量肝脏信号SI、噪声SD并计算肝脏信噪比SNR、对比噪声比CNR。采用独立样本t检验分析或者非参数秩和检验。结果主观评价:两种模式下所有期相图像运动伪影得分分别为(3.7±0.7)、(3.9±0.8),差异有统计学意义(P<0.05);两种模式之间的动脉晚期、门静脉期、延迟期图像的所有主观评分比较均无统计学意义(P>0.05)。Grasp-vibe序列组的动脉晚期分别和门静脉期、延迟期比较显示:对肝脏锐利度的评价差异无统计学意义(P>0.05),其余评分差异有统计学意义(P<0.05)。客观评价:两种模式下门静脉期的SD值分别为7.6(6.7,8.7)、6.1(4.3,7.2),差异有统计学意义(P<0.05),CDT-vibe序列的SD值高;其余客观评价均差异无统计学意义(P>0.05)。结论基于压缩感知的Grasp-vibe序列在肝脏MR增强后的图像质量初步满足诊断要求,其自由呼吸的意义可以使绝大部分患者得到较满意的检查。

Objective To compare the image quality of Grasp-vibe sequence and the combined sequence of CDT-vibe and Dixon-vibe in liver MR enhancement,and to analyze the application value of Grasp-vibe sequence.Methods A total of 70 patients who came to our hospital for examination due to liver occupancy and increased Ca199 found in physical examination from October to November 2020 were collected retrospectively.There were 35 patients in each of the two scanning methods.A 5-point system was used to evaluate the subjective scores of images in the late arterial phase,portal vein phase,and lag phase in the two modes,and the motion artifact scores of all sequences.We measured liver signal and noise,and calculated liver signal-to-noise ratio and contrast-to-noise ratio and analyzed the data using us independent sample t test analysis or non-parametric rank sum test.Results Subjective evaluation:the motion artifact scores of all phase images under the two modes were(3.7±0.7)and(3.9±0.8)respectively,and the difference was statistically significant;There was no statistically significant comparison of all subjective scores in the late arterial,portal venous,and the delayed images between the two modes.Comparison of the late arterial phase with the portal vein phase and the delayed phase in the Grasp-vibe sequence group showed that the evaluation of liver sharpness was not statistically significant,and the rest of the scores was statistically significant.Objective evaluation:The SD values of the portal phase under the two models were 7.6(6.7,8.7)and 6.1(4.3,7.2)respectively,and the difference was statistically significant.The SD value of the CDT-vibe sequence was high;The other objective evaluations were not statistically significant.Conclusion The image quality of Grasp-vibe sequence based on compressed sensing after liver MR enhancement meets the diagnostic requirements.The meaning of free breathing can make most patients get a more satisfactory examination.