| 摘要: |
| 目的 探讨在320排CT上应用70 kV管电压、低造影剂用量、低造影剂流速的扫描方案对BMI≤30 kg/m2患者行冠状动脉CT血管成像检查的可行性。方法 连续纳入我院2021年1－4月BMI≤30 kg/m2、拟诊或确诊冠状动脉疾病的患者52例，均通过宽体探测器CT前瞻性心电门控轴位扫描模式采集数据。将52例患者随机分为两组： 70 kV组（采用70 kV管电压及低造影剂用量和流速）和120 kV组（采用120 kV管电压及常规造影剂用量和流速）。两组均采用混合迭代算法重建图像。统计分析患者的年龄、体重、BMI、心率、造影剂用量及造影剂流速等，评估冠状动脉各节段血管的客观和主观图像质量，并分析比较两组的辐射剂量。结果 70 kV组患者造影剂用量及流速均低于120 kV组［（27.15±3.70） mL vs（48.92±5.08） mL、（2.71±0.37） mL/s vs（4.50±0.35） mL/s，P均＜0.001］。两组患者的客观图像质量指标中冠状动脉平均CT值、信噪比及对比噪声比差异均无统计意义（P均＞0.05），而70 kV组的图像噪声高于120 kV组［（31.50±5.74） HU vs（28.26±5.17） HU，P＝0.037］。共770个冠状动脉节段纳入主观评估，2名观察者之间的图像主观评分一致性较好（Kappa值＝0.772）； 70 kV组与120 kV组冠状动脉平均评分及优良率差异均无统计学意义［（1.17±0.38）分vs（1.21±0.43）分、100.00%（384/384）vs 98.96%（382/386），P均＞0.05］。70 kV组有效辐射剂量、CT容积剂量指数与辐射剂量长度乘积均低于120 kV组［（0.80±0.16） mSv vs（3.13±0.67） mSv、（4.51±0.98） mGy vs（17.36±3.19） mGy、（57.32±11.32） mGy·cm vs（223.61±47.64） mGy·cm，P均＜0.001］。结论 在320排CT上采用70 kV管电压对BMI≤30 kg/m2患者行冠状动脉血管成像检查是可行的，在亚毫希沃特条件下可获得满足临床诊断的图像，且较常规扫描方案降低了碘造影剂用量和流速。 |
| 关键词: 冠状动脉疾病 冠状动脉计算机断层扫描血管成像 宽体探测器 造影剂 低管电压 |
| DOI：10.16781/j.CN31-2187/R.20210855 |
| 投稿时间：2021-08-30修订日期：2022-01-06 |
| 基金项目:国家重点研发计划(2016YFC0104610). |
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| Application of 320-slice CT ultra-low tube voltage in coronary angiography patients with body mass index ≤30 kg/m2 |
| JIA Zi-jun,YIN Wei,HU Xin-xin,LI Jia-yu,LU Jian-ping,WANG Min-jie* |
(Department of Radiology, The First Affiliated Hospital of Naval Medical University (Second Military Medical University), Shanghai 200433, China
*Corresponding author) |
| Abstract: |
| Objective To explore the feasibility of coronary artery computed tomography (CT) angiography in patients with body mass index (BMI)≤30 kg/m2 using 320-slice CT with 70 kV tube voltage and low contrast agent dose and flow rate.Methods Fifty-two consecutive patients with BMI≤30 kg/m2 and suspected or diagnosed coronary artery diseases were enrolled in our hospital from Jan.to Apr.2021.The data were collected by wide detector CT prospective electrocardiographically-gated axial scan mode.All the patients were randomly divided into 2 groups:70 kV group (using 70 kV tube voltage and low contrast agent dose and flow rate) and 120 kV group (using 120 kV tube voltage and conventional contrast agent dose and flow rate).In both groups,images were reconstructed using a hybrid iterative algorithm.Patients’ age,weight,BMI,heart rate,amount of contrast agent and flow rate were statistically analyzed to evaluate the objective and subjective image quality of the vessels in each segment of the coronary arteries,and radiation doses of the 2 groups were analyzed and compared.Results The contrast agent dose and flow rate in the 70 kV group were significantly lower than those in the 120 kV group (［ 27.15±3.70］ mL vs［ 48.92±5.08］ mL,［ 2.71±0.37］ mL/s vs［ 4.50±0.35］ mL/s,both P＜0.001).There were no significant differences in coronary mean CT values,signal to noise ratio or contrast to noise ratio between the 2 groups of patients in objective image quality measures (all P＞0.05),while the image noise of the 70 kV group was significantly higher than that of the 120 kV group (［31.50±5.74］ HU vs［28.26±5.17］ HU,P＝0.037).A total of 770 coronary artery segments were included for the subjective assessment,and the image subjective rating agreement between the 2 observers was good (Kappa＝0.772).There were no significant differences in coronary artery subjective quality average score or excellent and good rate between 70 and 120 kV groups (1.71±0.38 vs 1.21±0.43,100.00%［ 384/384］ vs 98.96%［382/386］,both P＞0.05).The effective dose,CT volume dose index and dose-length product were significantly lower in the 70 kV group than those in the 120 kV group (［0.80±0.16］ mSv vs［3.13±0.67］ mSv,［4.51±0.98］ mGy vs［17.36±3.19］ mGy,［57.32±11.32］ mGy·cm vs［223.61±47.64］ mGy·cm,all P＜0.001).Conclusion It is feasible to use 320-slice CT with 70 kV tube voltage for coronary angiography in patients with normal BMI.Under the condition of sub-mSv,images meeting the clinical diagnosis can be obtained,and the dose and flow rate of iodine contrast agent are greatly reduced compared with the conventional scan mode. |
| Key words: coronary artery diseases coronary computed tomography angiography wide detector contrast agents low tube voltage |
