Abstract: Objective　To compare the application effects of different doses of low-radiation manual trigger technology in multi-slice spiral CT pulmonary artery angiography. Methods　A total of 90 cases of pulmonary embolism treated in Luanzhou People's Hospital from April 2020 to April 2021 were selected and were divided into 2 groups according to the time of admission with 45 cases in each group. Both groups received multi-slice spiral CT scanning. In the control group, there were 20 males and 25 females, aged (49.98±10.03) years, and the conventional dose (60 ml) low-radiation manual trigger technique was used; in the observation group, there were 24 males and 21 females, aged (50.49±10.06) years, and the low-dose (30 ml) low-radiation manual trigger technique was used. The radiation dose, image quality, CT value, and contrast-to-noise ratio (CNR) were compared between the two groups. χ² test was used for the count data, and independent sample t test was used for the measurement data. Results　The CT volume dose, dose-length product, and effective dose in the observation group [(5.42±1.03) mGy, (112.98±20.45) mGy·cm, and (2.30±0.32) mSv] were significantly lower than those in the control group [(11.14±2.16) mGy, (313.76±25.43) mGy·cm, and (5.27±0.88) mSv], with statistically significant differences (all P<0.05). There were no statistically significant differences in the calculated signal-to-noise ratio, and signal intensity between the two groups (all P>0.05). The background noise and image quality score in the observation group [(15.67±0.48) Hu and (4.78±1.02) points] were higher than those in the control group [(8.31±0.35) Hu and (3.55±0.78) points], with statistically significant differences (both P<0.05). The CT value of the observation group was higher than that of the control group [(452.96±24.38) Hu vs. (387.12±43.09) Hu], and the CNR value of the observation group was lower than that of the control group [(33.17±3.54) vs. (36.21±4.36)], with statistically significant differences (both P<0.05). Conclusions　Different doses of low-radiation manual trigger technique can obtain the images of the same quality in multi-slice spiral CT scanning of pulmonary artery vessels. However, low-dose manual trigger technique can significantly reduce the dose of contrast agent and radiation, and improve the reasonable utilization of medical resources.

Key words: Pulmonary embolism, Low-radiation manual trigger technique, Multi-slice spiral CT, Dose, Angiography

摘要： 目的　对比不同剂量的低辐射手动触发技术在多排螺旋CT肺动脉血管成像中的应用效果。方法　选取2020年4月至2021年4月在滦州市人民医院接受治疗的肺动脉栓塞患者90例，按照入院时间分为两组，各45例。均给予多排螺旋CT扫描，其中对照组男20例、女25例，年龄（49.98±10.03）岁，选择常规剂量（60 ml）低辐射手动触发技术；观察组男24例、女21例，年龄（50.49±10.06）岁，选择小剂量（30 ml）低辐射手动触发技术。对比两组辐射剂量、图像质量、CT值及对比噪声比（CNR）值。计数资料采用χ²检验，计量资料采用独立样本t检验。结果　观察组CT容积剂量、剂量长度积及有效剂量［（5.42±1.03）mGy、（112.98±20.45）mGy·cm、（2.30±0.32）mSv］均显著少于对照组［（11.14±2.16）mGy、（313.76±25.43）mGy·cm、（5.27±0.88）mSv］，差异均有统计学意义（均P<0.05）。两组计算信噪比、信号强度比较，差异均无统计学意义（均P>0.05）；观察组背景噪声、图像质量评分［（15.67±0.48）Hu、（4.78±1.02）分］均高于对照组［（8.31±0.35）Hu、（3.55±0.78）分］，差异均有统计学意义（均P<0.05）。观察组CT值高于对照组［（452.96±24.38）Hu比（387.12±43.09）Hu］，CNR值低于对照组［（33.17±3.54）比（36.21±4.36）］，差异均有统计学意义（均P<0.05）。结论　不同剂量低辐射手动触发技术在多排螺旋CT扫描肺动脉血管中取得质量相同的图像时，小剂量的低辐射手动触发技术能够显著减少对比剂与辐射的使用剂量，提高了医疗资源的合理利用率。

关键词: 肺动脉栓塞, 低辐射手动触发技术, 多排螺旋CT, 剂量, 血管成像