摘要
目的 通过测量多层螺旋CT和单源能谱CT在下肢骨折病例图像的噪声及对比噪声比（Contrast to noise ratio,CNR）,比较其在辐射剂量上的差异,评估单源能谱CT扫描的临床应用价值.方法 收集临床诊断下肢骨折病例39例,术前或术后行多层螺旋CT扫描,术后或术后随访行单源能谱CT扫描,分别获得两组图像,测量并比较常规CT组与能谱组130千电子伏特（kev）（在之前研究中显示消除金属伪影、图像主观评分最高的光子能级）无明显伪影区松质骨的背景噪声及图像的对比噪声比（CNR）和辐射剂量的差异,并行配对样本t检验.结果 两组数据为同一患者术前、术后或术后复查图像,其体质量指数（BMI）差异忽略不计,常规组的CT容积剂量指数为（7.94±1.69） mGy,术后能谱CT组容积剂量指数为（7.04±0.97）mGy,差异有统计学意义（t=2.71,P＜0.05）;常规组、能谱组图像噪声分别为（44.36±15.66） Hu和（15.04±8.23）Hu,差异有统计学意义（t=15.26,P＜0.05）;常规组的骨CNR为（3.96±1.78）,能谱组的骨CNR为（4.62±2.80）,其差异有统计学意义（t=-2.14,P＜0.05）.结论 与常规多层螺旋CT成像相比,单源能谱CT在降低辐射剂量的前提下,提高了图像对比噪声比,明显消除金属伪影,更好地显示下肢骨折术后复杂结构.
Objective To assess the clinical application value of single-source dual energy CT（SSDE）,by measuring the multi-slice CT（MSCT） and single-source dual energy CT（SSDE） lower limb fractures image noise and contrast noise ratio（CNR）,comparing the difference in the radiation dosage.Methods 39 cases of lower extremity fractures by clinical diagnosis were included in the study.Preoperation or postoperation the patients underwent MSCT scans,postoperation or postoperative follow-up SSDE CT scans were conducted,two sets of images were achieved.We measured and compared conventional CT group with 130 key energy spectrum group （prior studies showed the elimination of metal artifacts,images,subjective scoring the highest photon energy level） no significant artifacts cancellous bone area,compared the image background noise and contrast noise ratio （CNR）,and radiation dosage,using paired sample t-test.Results Two sets of data for the same patient before and after surgery or after review of images,which body mass index （BMI） was negligible.The CTDIvol value of the conventional MSCT was （7.94 ± 1.69） mGy,the dual-energy CT was （7.04 ± 0.97） mGy,with significant difference （t =2.71,P 〈 0.05） ; The image noise of the conventional MSCT was （44.36 ± 15.66） Hu,the dual-energy CT was （15.04 ± 8.23） Hu,with significant difference （t =15.26,P 〈 0.05） ; The CNR of the conventional MSCT was （3.96 ± 1.78）,the dual-energy CT was （4.62 ± 2.80）,with significant difference （t =-2.14,P 〈 0.05）.Conclusion Compared with conventional MSCT,single source dual-energy CT imaging provides improved image CNR,obviously eliminate metal artifacts,to better show the complex structure for lower limb fracture surgery,and reduction in radiation dosage.
出处
《中国基层医药》
CAS
2015年第4期500-503,I0002,共5页
Chinese Journal of Primary Medicine and Pharmacy
基金
浙江省温州市科技局课题编号：Y2013S00097
关键词
骨折
体层摄影术
X线计算机
辐射剂量
Fractures,Bone
Tomography,X-Ray Computed
Radiation Dosage
