基于压缩感知加速的肩关节运动不敏感质子密度加权成像

Acceleration of Motion-Insensitive Proton Density Weighted Imaging of Shoulder by Compressed Sensing

目的:探索不同压缩感知(CS)加速因子(AF)结合不同风车采集(MV)填充百分比(AQP)对肩关节质子密度加权成像(PDWI)图像质量的影响。方法:招募志愿者41例[男16人,女25人,平均年龄(36.78±14.37)岁],对所有受检者应用3.0TMR设备进行常规PDWI序列以及不同AF和AQP组合的PDWI序列检查(包括SENSE2&150%、CS-AF2&150%、CS-AF2&200%、CS-AF2&250%、CS-AF3&200%、CS-AF4&200%、CS-AF4&250%),分别定义为A~G组。2名观察者在肩关节PDWI冠状位原始图上划定感兴趣区,测量信号强度和标准差,并计算信噪比(SNR)和对比度噪声比(CNR),并采用5分法对图像进行主观评分;使用组内相关系数(ICC)及Kappa检验评估2名观察者测量数据和主观评分的一致性;对各组间图像的SNR、CNR和主观评分采用单因素ANOVA分析进行比较。结果:2名观察者测量数据和主观评分一致性良好(ICC:0.830~0.928;Kappa:0.853~951)。各组之间的SNR、CNR和主观评分均无统计学差异。结论:在肩关节PDWI中采用AF=CS3和MVAQP200%的扫描方案,在确保图像质量达到诊断需求的同时,将扫描时间缩短24%(从85s降至65s),值得推荐用于临床常规检查。

Purpose:To explore the impacts of different acceleration factors(AFs)of compressed SENSE(CS)combined with different multivane(MV)acquisition percentages(AQP)on the image quality of proton density weighted imaging(PDWI)of shoulder.Methods:A total of 41 volunteers[16 males and 15 females;mean age:(36.78±14.37)years]were recruited.All the subjects were examined with 3.0 T MR equipment(Ingenia CX,Philips Healthcare,Best,the Netherlands)for conventional PDWI sequences and PDWI sequences of different AF and MV AQP combinations,including SENSE2&150%,CS-AF2&150%,CS-AF2&200%,CS-AF2&250%,CS-AF3&200%,CS-AF4&200%,CS-AF4&250%,respectively defined as A-G group.Two observers demarcated the region of interest on the original coronal image of shoulder joint PDWI,measured the signal intensity and standard deviation,calculated the signal-to-noise ratio(SNR)and the contrast-to-noise ratio(CNR),and scored the image subjectively by using the five-point method.Intraclass correlation coefficient(ICC)and Kappa test were used to evaluate the consistency of measurements and subjective scores between the two observers.The SNR,CNR and subjective scores of the images were compared by one-way ANOVA analysis.Results:There was a good agreement between the measurement data and subjective scores of the two observers(ICC:0.830-0.928;Kappa:0.853-951).There were no significant differences in SNR,CNR and subjective scores among the groups.Conclusion:AF=CS3 and MV AQP 200%scanning protocols were used in PDWI of shoulder joint,which could not only ensure the image quality to meet the diagnostic requirements,but also reduce the scanning time by 24%(from 85 seconds to 65 seconds),which is worthy of recommendation for clinical routine examination.