不同心率下体质量对双源CT冠状动脉造影强化效果的影响

Effect of body weight on arterial enhancement with deferent heart rate in coronary dual-source CT angiography

摘要:

目的 探讨不同心率下体质量对双源冠状动脉CT血管造影强化效果的影响。方法 前瞻性纳入射血分数(ejection fraction, EF)正常（EF为50%～70％）的患者136例，根据心率分为4组，A组： 50～59次/min；B组： 60～69次/min；C组： 70～79次/min；D组： 80～89次/min。对比剂的剂量根据体质量进行调整(230mgI/kg)，注射速率5mL/s，随后以相同速率追加30mL生理盐水。计算4组中左主干（left main, LM）的平均CT值。先整体评估所有患者的体质量和心率与LM的CT值的相关性，再于每一组内评估体质量与LM的CT值的相关性。结果 整体评估所有患者，显示LM的CT值与心率呈负相关（r=-0.211，P<0.05），与体质量呈负相关（r=-0.250，P<0.05）。组内分析，显示A组和B组中LM的CT值与体质量呈负相关（A组： r=-0.561，P<0.05；B组： r=-0.380，P<0.05）。C组和D组中LM的CT值与体质量无明显相关性（C组： r=-0.075，P=0.650；D组： r=-0.073，P=0.766）。结论 在根据体质量调整对比剂量的注射方案中，心率较低的患者组，冠状动脉的强化效果与体质量呈负相关；心率较高的患者组，体质量不同的患者冠状动脉强化均一性好。

Abstract:

Objective To study the effect of body weight(BW) on the arterial enhancement among the patients with different HR(heart rate) in coronary CT angiography. Methods One hundred thirty six patients with normal EF(ejection fraction)(50%70%) were enrolled and assigned to four groups by HR,(group A: HR 5059bpm, group B: HR 6069bpm, group C: HR 7079bpm; group D: HR 8089bpm). The dose of contrast media(CM) was tailored to BW(230mgI/kg), followed by a chaser bolus of 30mL saline at the same rate(5mL/s). The mean attenuation of the left main coronary artery(LM) was calculated in four groups. The correlations of BW and HR with the attenuation of LM were evaluated in all patients, and the correlation between body weight and the attenuation of LM was also evaluated in each group. Results The overall evaluation showed that the attenuation of LM was negatively correlated with HR(r=-0.211, P<0.05) and BW(r=-0.250, P<0.05). For each group, the attenuation of LM was negatively correlated with BW in group A(r=-0.561, P<0.05) and in group B(LM: r=-0.380, P<0.05); there were no significant correlations with BW in group C(LM: r=-0.075, P=0.650) and in group D(LM: r=-0.073, P=0.766). Conclusion When the contrast dose is tailored to BW, the attenuation of coronary artery is negatively correlated with BW in patient with lower HR; however, for patient with higher HR, the coronary artery enhancement is similar among patients with different BW.