第三代双源CT不同扫描模式抑制下颈部伪影的对比

Comparison on the suppression of the artifacts in lower neck artery examination by the third-generation dual-source CT in different scanning mode

目的:通过对比下颈部CT常规扫描、双能量模式扫描、无预设值CARE kV联合CARE Dose 4D自动控制曝光技术,探索下颈部CT扫描抑制伪影的个性化方案.方法:随机选取进行下颈部CT检查的患者99例,分成3组,A组:固定千伏、毫安扫描;B组:无预设值CARE kV联合CARE Dose 4D自动控制曝光技术扫描;C组:双能量模式扫描,分别将图像质量评分、噪声值、信噪比及容积CT剂量指数进行对比.结果:C组图像质量评分(3.70±0.51)高于B组(3.36±0.50),P<0.05,B组图像质量评分(3.36±0.50)明显高于A组(3.00±0.59),P<0.01;B组容积CT剂量指数(6.38±1.40)mGY明显低于A组(9.29 mGY),P<0.01;A组容积CT剂量指数(9.29mGY)明显低于C组(12.58±4.74)mGY,P<0.01;C组噪声值(7.51±2.29)明显低于A组(12.03±3.52)、B组(12.18±4.47),两者P<0.01;C组信噪比(7.57±2.20)明显高于A组(5.19±1.86)、B组(5.51±1.86),两者P<0.01;A、B组噪声值、信噪比无明显统计学意义(分别为P=0.86,P=0.52).结论:建议常规下颈部CT扫描使用无预设值CARE kV联合CARE Dose 4D自动控制曝光技术,可获得辐射剂量最低、图像质量较优的影像,而双能量扫描模式能更大程度抑制下颈部伪影,在诊断下颈部疑难病变、定位细微病灶时,或在征得病人同意的情况下,可使用双能量模式获得更高质量的影像.

Objective:To explore a an individualized program for suppressing artifact in CT scan of the cervix through comparing the difference of the CT routine scan,dual energy mode scan,the non-presetting intelligent optimal tube voltage scanning(CARE KV)combined with automatic tube current modulation(CARE Dose 4D)technology on the cervix.Methods:Nighty-nine patients received the cervix CT examination in our hospital were randomly selected and divided into 3 groups,33 cases each.Patients in group A received the conventional fixed kilovolt and milliampere CT scan,and patients in group B received the non-presetting intelligent optimal tube voltage scanning(CARE KV)combined with automatic tube current modulation(CARE Dose 4D)technology,and patients in group C received dual energy mode CT scan.Eventually the image quality(noise,SNR,subjective ratings)and radiation dose(CTDI vol)of the three groups were compared.Results:The image quality score of group C(3.70±0.51)was higher than that of group B(3.36±0.50)(P<0.05),and the image quality score of group B(3.36±0.50)was higher than that of group A(3.00±0.59)(P<0.01).The CT Volume dose index of group B(6.38±1.40 mGY)was lower than that of group A(9.29 mGY)(P<0.01),and the CT volume dose index of group A(9.29 mGY)was lower than that of group C(12.58±4.74 mGY)(P<0.01).The noise of group C(7.51±2.29)was obviously lower than that of group A(12.03±3.52)and group B(12.18±4.47)(P<0.01),while the SNR between group C(7.57±2.20)was obviously higher than that of group A(5.19±1.86)and group B(5.51±1.86)(P<0.01).The noise and SNR of group A and B showed no significant difference(group A P=0.86,group B P=0.52).Conclusion:It suggests that routine cervix scan using the non-presetting intelligent optimal tube voltage scanning(CARE KV)combined with automatic tube current modulation(CARE Dose 4D)technology in order to obtain the image with the lowest radiation dose and the higher quality.While diagnosing perplexing neck lesions and locating small lesions,dual energy mode scan can be used to obtain image of even higher quality with the consent of the patients.