迭代模型重建技术在腰椎低剂量CT扫描中的应用  

Application of iterative model reconstruction technique in low-dose lumbar CT scanning

作　　者：朱维聪 曾慧芸 杜晨 吴雅婷 王彬 ZHU Weicong;ZENG Huiyun;DU Chen;WU Yating;WANG Bin(Department of Radiology,Dongguan Kanghua Hospital,Dongguan,Guangdong Province 523000,China)

机构地区：[1]东莞康华医院放射科,广东东莞523000

出　　处：《实用放射学杂志》2025年第2期323-327,共5页Journal of Practical Radiology

摘　　要：目的探讨迭代模型重建(IMR)技术在腰椎低剂量CT扫描中的应用价值。方法选取行腰椎CT平扫的患者48例,将其分为常规剂量组(A组)和超低剂量组(B组),A组采用管电压120 kV、自动管电流调制技术和iDose 4重建获得图像;B组管电压100 kV,管电流80 mAs,分别采用iDose 4和IMR,得到B1、B22组图像。在L3~L4椎体层面分别测量并计算骨松质、椎间盘、硬膜囊及腰大肌的标准差(SD)值(以SD值代表测量组织的噪声)、信噪比(SNR)和对比噪声比(CNR);2名诊断医师对图像进行质量评分;采用样本t检验及方差分析对测量结果和主观评分进行比较。结果椎间盘、硬膜囊及腰大肌噪声的比较均显示B2组<A组<B1组、主观评分的比较均显示A组>B2组>B1组,椎间盘及腰大肌SNR均显示B2组>A组>B1组。A组和B1组骨质评分的比较差异无统计学意义(P>0.05),而B2组骨质评分与iDose4重建获得的图像(A组、B1组)比较均有显著差异(P<0.05)。B组有效剂量(ED)较A组下降约70.28%。结论IMR能够显著降低图像SD、提高图像SNR和CNR,获得高质量图像,相比于iDose 4技术在软组织显示方面更有优势,而使用iDose 4技术获取图像观察骨质精细结构更有优势,iDose 4和IMR技术联合应用既保证了诊断所需的优质图像,又可显著降低患者辐射剂量。Objective To explore the application value of iterative model reconstruction(IMR)technique in low-dose lumbar CT scanning.Methods A total of 48 patients who underwent lumbar CT plain scan were selected and divided into regular-dose group(group A)and ultra-low dose group(group B).The group A underwent imaging with 12o kV tube voltage,automatic tube current modulation technology,and iDose 4 reconstruction.The group B was scanned with a tube voltage of 1oo kV and a tube current of 80 mAs,and the images of Bl and B2 groups were reconstructed by iDose 4 and IMR,respectively.The standard deviation(SD)value(the SD value represents the noise of the measured tissue),signal-to-noise ratio(SNR),and contrast-to-noise ratio(CNR)of cancellous bone,intervertebral disc,dural sac,and psoas muscle were measured and calculated at the L3-L4 vertebral body level.Two diagnosticians rated the image quality.Sample t-test and ANOVA were used to compare the measurement results and subjective scores.Results The comparison of SD for intervertebral disc,dural sac,and psoas muscle showed group B2<group A<group Bl,while the subjective score comparison indicated group A>group B2>group B1.The SNR for intervertebral disc and psoas muscle demonstrated group B2>group A>group B1.There was no significant difference in bone quality score between group A and group B1(P>0.05),but there was a significantly different between the bone quality scores of group B2 and those obtained with iDose 4 reconstruction(group A and group B1)(P<0.05).The effective dose(ED)of group B was reduced by approximately 70.28%compared with group A.Conclusion IMR can significantly reduce SD,improves SNR and CNR,resulting in high-quality images.Compared to iDose 4 technique,IMR has more advantages in soft tissue display,while iDose 4 technique is superior in observing fine bone structures.The combined application of iDose 4 and IMR technique ensures high-quality images for diagnosis,while significantly reducing the radiation dose to patients.

关 键 词：迭代模型重建 计算机体层成像 辐射剂量 腰椎 

分 类 号：R814.42[医药卫生—影像医学与核医学] R814.49[医药卫生—放射医学] R322.71[医药卫生—临床医学]