基于压缩感知技术的快速自旋回波扩散加权成像在颅底成像中的应用  

Application of Compressed Sensing Technology in the Fast Spin Echo Diffusion Weighted Imaging of the Skull Base

作　　者：张浩南 宋清伟[1] 张楠 宋宇 浦仁旺[1] 王楠[1] ZHANG Haonan;SONG Qingwei;ZHANG Nan(Department of Radiology,The First Affiliated Hospital of Dalian Medical University,Dalian,Liaoning Province 116011,P.R.China)

机构地区：[1]大连医科大学附属第一医院放射科,116011 [2]四川大学华西第二医院放射科,成都610041

出　　处：《临床放射学杂志》2022年第2期340-345,共6页Journal of Clinical Radiology

基　　金：辽宁省教育厅2021年度科学研究经费项目(编号:LJKZ0855);大连医科大学附属第一医院横向课题基金项目(编号:2021HZ006)。

摘　　要：目的探讨压缩感知(CS)加速因子(AF)对颅底部快速自旋回波扩散加权成像(TSE-DWI)图像质量的影响。方法招募健康受检者22名、固定义齿受检者22例,颅底部病变受检者11例,平均年龄为(53.42±18.00)岁、(57.77±19.65)岁、(48.55±18.31)岁,分别为A、B、C组。所有志愿者均行平面回波成像扩散加权成像(EPI-DWI)扫描时间32 s;以及结合传统平行采样技术(SENSE)或CS的TSE-DWI。SENSE采用AF为2.6,CS采用AF为2.6、3.6、5.6和7.6,对应扫描时间分别为146 s、146 s、114 s、89 s和75 s。A、B组在EPI-DWI与TSE-DWI b=1000 s/mm^(2)图像小脑最大层面及上下各一个层面两侧小脑和脑干脑桥实质区域划定感兴趣区(ROI)测量表观扩散系数(ADC)值和信号强度(SI);C组在b=1000 s/mm^(2)图像病灶最大层面及上下各一个层面划定ROI测量ADC值和SI。并在齿状核最大层面测量两侧齿状核SI和噪声强度(SD),计算信噪比(SNR)和对比噪声比(CNR)。由两名观察者对图像质量进行四分法主观评分。Kappa检验两观察者评分的一致性,若一致性良好,选择高年资医师主观评分进行后续分析。使用Friedman检验A、B、C组TSE-DWI不同AF两侧小脑、脑干脑桥、病变ADC值、SNR、CNR及主观评分的差异性。若差异性有统计学意义,使用Wilcoxon检验进行两两比较。后续选择最优AF与EPI-DWI进行比较。结果两观察者图像质量主观评分一致性良好(Kappa值0.772、0.831、0.828)。TSE-DWI不同AF比较,A组右侧小脑和脑桥脑干ADC,B组右侧小脑和左侧脑干脑桥ADC差异无统计学意义。两两比较,A组当AF为CS 5.6时,其左侧小脑CNR、右侧脑桥脑干SNR、CNR以及图像评分较SENSE 2.6差异有统计学意义(P<0.05);B组AF为CS 5.6时,左侧小脑和脑桥脑干SNR、CNR、右侧小脑和脑桥脑干CNR及图像评分较SENSE 2.6差异有统计学意义(P<0.05);C组AF为5.6时,病变处CNR较SENSE 2.6差异有统计学意义(P<0.05)。后续TSE-DWI CS 3.6与EPI比较,B、C�Objective Exploring the effect of the compression sensing acceleration factor on the image quality of TSE-DWI in the skull base area. Methods The study population consisted of 22 healthy subjects(53.42±18.00)years,22 subjects with dentures(57.77±19.65)years and 11 subjects with skull base lesions(48.55±18.31)years, defined as group A,B and C,respectively.All subjects underwent the EPI-DWI and TSE-DWI scan of Skull Base.Scan durations of EPI-DWI was 32 s.TSE-DWI adopted a routine clinical setup of SENSE acceleration factor(AF) 2.6,and CS factors of 2.6,3.6,5.6 and 7.6.Scan durations of each sequences were 146 s、146 s、114 s、89 s、75 s, respectively.In the b=1000 s/mm^(2)image, the largest level of the cerebellum and the upper and lower levels of the cerebellum and the brain stem and pons on the left and right sides of the brain parenchymal regions delineate the regions of interest to measure the ADC value and signal intensity.In group C,ROI was delineated to measure the ADC value and signal intensity at the largest layer of the b=1000 s/mm^(2) image lesion and the upper and lower layers.The signal intensity and noise intensity of the dentate nuclei on both sides are measured at the largest level of the dentate nucleus, based on which Signal to Noise Ratio(SNR) and Contrast to Noise Ratio(CNR) were calculated for all volunteers.The two observers used a four-point scoring method to evaluate the quality of the images.The Kappa test was adopted to evaluate the consistency of the scores from the two radiologists.If the consistency was in good agreement, the corresponding images would be adopted for further analysis by senior physicians.In the following analysis, the Friedman test was used to test the differences of the cerebellum, brainstem and pons, ADC value, SNR,CNR,and subjective scores on the two sides of TSE-DWI in groups A,B,and C,and the Wilcoxon test was employed to make a pairwise comparison.The optimal AF was selected subsequently for comparison with EPI-DWI. Results The scores by the two observers

关 键 词：颅脑 扩散加权成像 磁共振成像 压缩感知 

分 类 号：R445.2[医药卫生—影像医学与核医学]