【摘要】 目的探讨智能管电压辅助(kV Assist)技术降低腰椎CT检查辐射剂量的可行性及应用价值。方法前瞻性纳入临床拟诊为腰椎疾病需进行腰椎CT检查的病人60例,其中男55例,女5例,年龄(38.2±2.7)岁,体质量指数(BMI)为(21.8±1.1) kg/m~2。将病人随机分为A、B 2组,每组30例。A组采用常规模式扫描(120 kV,230 mA);B组采用kV Assist模式扫描。分别记录2种扫描模式的单次容积CT剂量指数(CTDIvol)、剂量长度乘积(DLP)、有效剂量(ED)。采用5分评分法对2组的影像质量进行主观评分,并计算骨算法骨窗及标准算法软组织窗影像的对比噪声比(CNR)和信噪比(SNR)。采用独立样本t检验比较2组病人的年龄、BMI及影像的CTDIvol、DLP、ED、SNR、CNR;采用Wilcoxon秩和检验比较2组影像的主观评分。结果 B组CTDIvol、DLP、ED均低于A组(均P<0.05),B组的辐射剂量降低约45%。B组骨算法骨窗影像的主观评分及CNR、SNR均高于A组(均P<0.05)。2组标准算法软组织窗影像的主观评分及CNR、SNR差异均无统计学意义(均P>0.05)。结论应用kV Assist技术进行腰椎CT检查能够降低辐射剂量且提高影像质量。更多还原

【Abstract】 Objective To explore the feasibility and application value of kV Assist technology in reducing radiation dose for lumbar CT examination. Methods Sixty patients with suspected of lumbar disease and requiring lumbar CT examination were prospectively enrolled in the study(55 males, 5 females, age 38.2±2.7 years, BMI 21.8±1.1 kg/m~2). The patients were randomly separated into two groups: group A(n=30) scaned using conventional mode(120 kV and 230 mA),and group B(n=30) scaned using kV assist. The volumetric CT dose index volume(CTDIvol), dose-length product(DLP), and effective dose(ED) were recorded. Subjective image quality was evaluated by a 5-grade scale. The contrast noise ratio(CNR)and signal to noise ratio(SNR) in the bone and soft tissue windows were calculated. The age, BMI, CTDIvol, DLP, ED, SNR,and CNR were compared with independent samples-t test, and the subjective image quality was compared with Wilcoxon rank sum test between the two groups. Results The group B had significant lower(over 45%) CTDIvol, DLP, and ED than the group A(all P<0.05). In the bone window, The group B had significantly higher CNR, SNR, and subjective image quality than the group A(all P <0.05). However, there were no statistically significant differences in CNR, SNR, and subjective image quality between group A and group B in the soft tissue window(P >0.05). Conclusion In lumber CT examination,application of kV Assist technique can reduce radiation dose and improve image quality.更多还原