【摘要】 目的 探讨64排螺旋CT肺动脉成像(CTPA)与应用低管电压结合高管电流技术在CTPA中碘对比剂用量、辐射剂量及图像质量对比性的研究。方法 随机将本院60例临床怀疑肺栓塞要求行CTPA分为3组：Ⅰ组20例，采用120 kV、180 mA,对比剂量为70 mL;Ⅱ组20例，采用100 kV、280 mA,对比剂量为50 mL;Ⅲ组20例，采用80 kV、自动管电流调制技术300～500 mA,对比剂量为30 mL。分别测量每组肺动脉3处中心区及1处段支的CT值和图像噪声；对2组图像的客观指标、主观图像质量评价、CT容积剂量指数(CTDIvol)、剂量长度乘积(DLP)和有效剂量(ED)进行比较，以评价低kV结合高mA、低对比剂量应用在MSCTPA扫描中的可行性。使用方差分析及t检验对3组数据进行两两比较分析。结果 与标准法的CTPA相比较，两低剂量组CTPA在所有肺动脉干中均具有较好的显示，3组在5分图像质量评分差异无统计学意义(P>0.05),而3组CT值、噪声、信噪比(SNR)、对比噪声比(CNR)均有统计学意义(P<0.01)。Ⅱ组、Ⅲ组CT辐射剂量CTDIvol、DLP均低于Ⅰ组，差异有统计学意义(P<0.01)。结论 在80 kV扫描条件下采用小剂量对比剂预注射法与传统方法比较，降低对比剂量同时可明显减少上腔静脉内对比剂的硬化伪影对右肺动脉观察的干扰，有利于减轻患对比剂肾病的危险且降低了患者的辐射剂量。更多还原

【Abstract】 Objective To compare the iodine contrast agent dosage,radiation dose and image quality in CT pulmonary angiography(CTPA) with low tube voltage and high tube current in 64-slice spiral CT.Methods 60 patients with suspected pulmonary embolism in our hospital were randomly chosen and divided into three groups:Group Ⅰ:20 patients,using 120 kV,180 mA,contrast dose of 70 mL.Group Ⅱ:20 patients,using 100 kV,280 mA,contrast dose of 50 mL.Group Ⅲ:20 patients,using 80 kV,automatic tube current modulation techniques(300-500 mA),comparative dose of 30 mL.CT values and image noise of three pulmonary central areas and a segment branch were measured in each group.Objective indicators,subjective image quality assessment,CT dose index volume(CTDIvol),dose-length product(DLP) and effective absorbed dose(ED) were compared in three groups to evaluate the value of low kV,high mA with low-contrast dose in CTPA.Analysis of variance and t-test was used for data analysis.Results Compared with those of the standard method of CTPA,all pulmonary dry in two groups of low dose were well displayed.There was no statistical significance between each two groups in image quality score(P> 0.05),but was statistical significance in CT values,noise,SNR and CNR(P<0.01).The CT radiation dose,CTDIvol and DLP of Group Ⅱ and Group Ⅲ were significantly lower than those of Group Ⅰ(P<0.01).Conclusion Compared with traditional methods,low dose contrast agent injections under 80 kV could reduce the dose of contrast agent and the effect of hardening artifacts due to contrast agent in superior vena cava on right pulmonary artery.It is helpful to reduce the risk of contrast induced nephropathy and reduce patients’ exposure to X-ray radiation.更多还原