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目的探讨双源CT的CARE-kV扫描技术对冠状动脉成像(CTCA)的辐射剂量及图像质量的影响。方法回顾性分析行CTCA检查的患者393例,根据管电压设置方法分为两组:A组189例,应用CARE-kV技术智能选择管电压;B组204例,根据患者的体重指数(BMI)确定管电压,两组均应用CARE Dose 4D技术自动选择管电流。测量并记录主动脉根部及左、右冠状动脉主干的CT值及其标准差(SD),并进一步计算对比噪声比(CNR)和信噪比(SNR)值,以用于客观图像质量评估。然后由两名医师通过5分评价法对两组图像质量进行主观评价,取其均值纳入统计学分析。比较两组CNR,SNR,CT剂量指数(CTDIvol),剂量长度乘积(DLP)。结果 A组客观图像质量优于B组(P<0.05),主观图像质量差异无统计学差异(P=2.18);A组较B组CTDIvol降低32.4%[(20.08±18.20)mGy vs(26.49±21.55)mGy,P=0.003],DLP降低22.93%[(279.88±268.55)mGy·cm vs(363.15±297.0)mGy·cm,P=0.043],且A组较B组明显增加了80 kV管电压的应用率(χ2=73.289,P<0.05)。结论应用CARE-kV智能最佳kV扫描技术进行冠状动脉成像,不仅能降低受检者接受的辐射剂量,而且能同时提高图像质量。
Objective To investigate the effects of dual-source CT scanning with CARE-kV on the radiation dose and image quality of coronary artery imaging (CTCA). Methods A retrospective analysis of 393 patients undergoing CTCA was performed and divided into two groups based on the tube voltage setting method: 189 cases in group A and CARE-kV technique were used to select the tube voltage intelligently. In group B, 204 patients were selected according to body mass index (BMI) The tube voltage was determined and both groups were automatically selected for tube current using the CARE Dose 4D technique. The CT values and standard deviations (SDs) of the aortic root and the left and right coronary arteries were measured and recorded, and the CNR and SNR values were further calculated for objective image quality assessment. Subjective evaluation was then made by two physicians on the five groups using the five-point evaluation method, and the mean was taken for statistical analysis. CNR, SNR, CT dose index (CTDIvol) and dose length product (DLP) were compared between the two groups. Results The objective image quality of group A was better than that of group B (P <0.05), and there was no significant difference in subjective image quality between group A and group B (P = 2.18); the CTDIvol of group A was reduced by 32.4% [(20.08 ± 18.20) mGy vs 21.55) mGy, P = 0.003], DLP decreased 22.93% [(279.88 ± 268.55) mGy · cm vs (363.15 ± 297.0) mGy · cm, P = 0.043] The application rate (χ2 = 73.289, P <0.05). Conclusion Coronary artery imaging using CARE-kV intelligent best kV scanning technique can not only reduce the radiation dose received by the examinee, but also improve the image quality at the same time.