单扇区扫描联合三段团注技术在实现64排CT胸痛三联“双低”检查中的应用

Application of Snapshot Segment Combined with Triphasic Bolus Injection Technique in “Triple Rule-out” 64-row CT Imaging for Double-low Scanning of Chest Pain

目的：探讨单扇区扫描联合三段团注技术在64排螺旋CT胸痛三联检查中的应用价值。方法：将50例临床表现急性胸痛并行64排螺旋CT胸痛三联CTA检查患者随机分为两组,两组均采用回顾性心电门控技术,扫描心率范围50~75次/min,身体质量指数范围18~28。A组为实验组,采用单扇区采集重建技术,管电压100 k V,对比剂三段式团注,用量60~70 m L。B组为对照组,采用多扇区采集重建技术,管电压120 k V,对比剂两段式团注,用量90~100 m L。比较两组上腔静脉、肺动脉、冠状动脉、主动脉及肺静脉的CT值和CNR（对比信噪比）,同时比较两组肺动脉、冠状动脉图像质量及辐射剂量的差别。结果：两组病例经t检验显示上腔静脉、肺动脉、冠状动脉、主动脉及实验组内肺动脉、肺静脉CT值均具有统计学差异（P〈0.05）。两组图像质量、噪声、CNR值无统计学差异（P〉0.05）,辐射剂量具有统计学差异（P〈0.05）,实验组较对照组辐射剂量降低40.19%。结论：单扇区扫描联合三段团注技术使对比剂用量和辐射剂量明显降低,图像质量改善,具有较大临床实用价值。

Objective： To investigate the clinical value of Snapshot segment（or single sector reconstruction） combined with triphasic bolus injection in ＂Triple Rule-Out（TRO）＂ 64-row CT imaging for double-low scanning of chest pain. Methods： A total of 50 patients with acute chest pain who underwent 64-row CT imaging for TRO CT angiography（TRO-CTA） examination were randomly divided into two groups. All patients underwent retrospective ECG-gated chest TRO-CTA scanning. The heart rates ranged from 50 to 70 bmp. The body mass index（BMI） of the patients ranged from 18 to 28. Group A was identified as experimental group, which were underwent Snapshot segment reconstruction technique at the voltage of 100 k V, and received triphasic bolus contrast media injection at a volume of 60-70 m L. Patients in Group B were included as the control, which were underwent multi-sector reconstruction technique at the voltage of 120 k V, and received dualphasic bolus contrast media injection at a volume of 90-100 m L. The CT values and contrast noise ratio（CNR） of superior vena cava, pulmonary arteries, coronary arteries, and thoracic aorta between the two groups were compared. Besides, the image quality of pulmonary arteries and coronary arteries, and the radiation dose were compared. Results： There were significant differences in the CT values of superior vena cava, pulmonary arteries, coronary arteries, and thoracic aorta were detected between two groups with Student＇s test was used（P 〈0.05）. There was statistical differences between the CT values of pulmonary arteries and veins in experimental group（P〈 0.05）. No significant differences were found in the image quality, noise, or CNR between two groups（ P 〉0.05）, whereas the radiation dose in experimental group was significantly reduced by 40.19% when compared to that of in the control group（P 〈0.05）. Conclusion： Snapshot segment combined with triphasic bolus injection technique could greatly reduce the contrast media and radiation dose as well as improved image quality, and it implied its great practicing value in the clinic.