摘要
目的探讨中低心率对双源CT低管电压冠状动脉成像的图像质量及辐射剂量的影响。方法对85例体质量指数（BMI）为17．51～30．00kg／m2、心率在91次／min（bpm）以下的可疑冠心病患者进行双源CT低管电压（100kVp）回顾性心电门控冠状动脉成像增强扫描，检查前不使用β受体阻滞剂控制心率。按患者扫描时的心率进行分组，≤59bpm为A组（27例），60—69bpm为B组（29例），／〉70bpm为C组（29例）。评价各组的最佳重建时相图像，记录各组的增强扫描序列的螺距、CT容积剂量指数（CTDIvol）、剂量长度乘积（DLP）及有效剂量（ED）值。应用单因素方差分析比较3组患者的扫描螺距、图像质量评分和辐射剂量值等。分析心率对冠状动脉成像图像质量及辐射剂量的影响。结果A、B、C组螺距分别为0．241±0．025、0．286±0．034、0．335±0．036；3组图像质量评分分别为（4．78±0．26）、（4．66±0．56）、（4．70±0．46）分；CTDIvol值分别为（18．06±5．16）、（19．62±7．15）和（17．50±7．13）mGy，ED值分别为（4．23±1．16）、（4．59±1．75）、（4．12±1．39）mSv。3组的螺距差异有统计学意义（F=60．00，P=0．00）；3组间的图像质量评分差异无统计学意义（F=0．53，P=0．59）；3组间CTDIvol差异无统计学意义（F=0．83，P=0．44），ED差异也无统计学意义（F=0．86，P=0．43）。结论中低心率对双源CT低管电压冠状动脉成像的图像质量影响很小，在自动心电门控剂量窗时，对辐射剂量的影响也很小。
Objective To evaluate the imaging quality and radiation doses of dual-source computed tomography （DSCT） coronary angiography at a low tube voltage in patients with medium and low heart rate . Methods Eighty-five patients [heart rate （HR） 〈91 beats per minute（bpm） ;body mass index（BMI） 17.51-30. 00 kg/m2] suspected of coronary artery disease received retrospectively ECG-gating coronary angiography with dual-source CT scanner （Somatom Definition, Siemens） at a tube voltage of 100 kVp. For all patients, no beta-blocker was used before CT scan. According to the HR, the patients were divided into three groups： Group A, HR ≤〈 59 bpm, n = 27; Group B, HR 60-69 bpm, n = 29; Group C, HR ≥70 bpm, n = 29. All images were transferred to a workstation for postprocessing. The best R-R interval reconstruction images of all groups were evaluated. The value of pitch, CT volume dosage index （CTDIvol）, dose length product （DLP）and effective close （ED）were recorded. The pitch, the score of imaging quality of coronary artery segments and the radiation dose were compared with one-way ANOVA. The influence of HR on image quality and radiation doses of coronary artery was analyzed. Results The value of pitch in Group A, Group B and Group C was 0.241 ±0.025, 0.286 ±0.034 and 0.335 ±0.036, respectively. The mean score of imaging quality of coronary artery segments in Group A, Group B and Group C was 4. 78 ± 0. 26, 4. 66 - 0. 56 and 4. 70 ± 0. 46, respectively. The value of CTDIvoi in Group A, Group B and Group C was （ 18.06 ±5. 16）, （ 19. 62 ±7. 15） and （ 17. 50 ±7. 13） mGy, respectively. The value of ED in group A, Group B and Group C was （4.23 ± 1.16）, （4.59 ± 1.75） and （4.12 ± 1.39） rosy, respectively. There was statistical difference in value of pitch among the three groups （ F =60. 00, P = 0. 00）. There were no statistical difference in score of imaging quality, CTDIvoI and value of ED among the three groups （ F=0. 53, P = 0. 59 ; F = 0. 83, P = 0. 44 ; F = 0. 86, P = 0. 43 ）. Conclusion Medium and low HR have little influences on image quality of dual-source CT coronary angiography at a low tube voltage. When the auto ECG-gating is selected,there is little influence on radiation dosage as well.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2011年第3期279-283,共5页
Chinese Journal of Radiology
关键词
辐射剂量
冠状血管
体层摄影术
X线计算机
心率
Radiation dosage
Coronary vessels
Tomography, X-ray computed
Heart rate
