第3代双源CT 70 kV大螺距扫描冠状动脉CT血管成像在不同体质量指数患者中的应用

Application of 70 kV Third-generation High-pitch Dual-source Coronary CT Angiography in Patients with Different Body Mass Index

目的评估第3代双源CT 70 kV和超低对比剂用量方案下大螺距扫描冠状动脉CT血管成像(CTA)在不同体质量指数(BMI)患者中的应用情况。方法回顾性分析100例接受第3代双源CT大螺距扫描冠状动脉CTA检查且管电压值均自主选择为70 kV患者的临床资料,根据BMI分为A(BMI≤24 kg/m2)、B(24 kg/m2<BMI<28 kg/m2)、C(BMI≥28 kg/m2)3组,比较各组间的基本信息、图像质量及有效剂量(ED)。结果 3组患者在年龄(H=2.36,P=0.78)、心率(H=3.51,P=0.80)和ED(H=1.77,P=0.12)方面差异均无统计学意义。A组主动脉根部的噪声值为21.66±4.00,明显低于C组的23.61±4.20(F=2.05,P=0.03);A组主动脉根部的信噪比为18.61±5.28,明显高于C组的14.75±2.58(F=5.31,P=0.02);其余客观图像质量参数在3组间差异均无统计学意义(P均>0.05)。A、B、C组的平均主观图像质量评分分别为(1.13±0.11)、(1.16±0.14)和(1.76±0.44)分,A组(Z=2.91,P=0.004)和B组(Z=2.27,P=0.021)均明显低于C组,A、B两组间差异无统计学意义(Z=1.03,P=0.37)。结论在70 kV结合超低对比剂用量方案下,第3代双源CT大螺距扫描冠状动脉CTA检查在BMI<28 kg/m2患者中的效果可能优于BMI≥28 kg/m2的患者。

Objective To investigate the optimized range of body mass index（ BMI） selection for patients undergoing 70 kV high-pitch dual-source coronary CT angiography（ CCTA） on the third-generation dual-source CT（ DSCT）. Methods Patients undergoing prospective high-pitch ultra-low contrast media（ CM）CCTA on the third-generation DSCT using the automatic tube voltage selection at 70 kV were included and divided into three groups： group A, with BMI≤24 kg / m^2; group B,with 24 kg /m^2 〈BMI 〈28 kg / m^2; and group C,with BMI≥28 kg / m^2. The baseline data, image quality results, and effective dose（ ED） were evaluated and compared. Results No significant difference was found in age（ H = 2. 36, P = 0. 78）, heart rate（ H =3. 51, P = 0. 80）, and ED（ H = 1. 77, P = 0. 12） among three groups. The noise of the aortic root in group A was（ 21. 66 ± 4. 00） HU, which was significantly lower than that in group C [（ 23. 61 ± 4. 20） HU ]（ F =2. 05, P = 0. 03）. The signal to noise ratio of aortic root in group A（ 18. 61 ± 5. 28） was significantly better than that in group C（ 14. 75 ± 2. 58）（ F = 5. 31, P = 0. 02）. No other significant difference in quantitative image quality were found among the three groups（ all P〉0. 05）. Subjective image quality in group A（ Z =2. 91, P = 0. 004） and B（ Z = 2. 27, P = 0. 021） were both significantly better than that in group C. Conclusion The ultra-low tube voltage（ 70 kV） combined with ultra-low CM CCTA protocol on third-generation highpitch DSCT may be better for patients with BMI 28 kg / m^2 than those with BMI ≥28 kg / m^2 in China.