肺动脉CT血管成像中不同呼吸指令对肺动脉强化效果的影响

The effect of breathing instructions on artery enhancement in pulmonary artery CT angiography

目的:探讨肺动脉CT血管成像(CTPA)中不同呼吸指令对肺动脉强化效果的影响。方法:连续纳入因疑诊肺栓塞行CTPA检查的患者192例,随机采用3种不同呼吸指令:深吸气后屏气(A组,84例)、平静呼吸轻屏气(B组,52例)和平静呼吸不屏气(C组,56例)。所有患者均采用相同扫描参数及对比剂注射方案,判断有无肺栓塞、一过性对比剂中断(TIC)或明显呼吸运动伪影,评估肺部图像质量,并比较3组肺动脉干CT值。结果:3组间一般资料及肺栓塞检出率差异均无统计学意义(均P>0.05)。A组TIC发生率高于B、C组,C组呼吸运动伪影发生率高于A、B组,差异均有统计学意义(均P<0.017)。3组肺部图像质量均能满足诊断,A组整体肺部图像质量优于B、C组(均P<0.017)。3组肺动脉干CT值分别为(311.42±77.49)、(341.94±82.10)、(345.77±66.16)HU,差异有统计学意义(P<0.05);两两比较,A组肺动脉CT值小于B、C组,差异均有统计学意义(均P<0.05),B、C组差异无统计学意义(P>0.05)。结论:平静呼吸轻屏气或不屏气状态下CTPA扫描较深吸气后屏气扫描肺动脉强化效果更好,建议将平静呼吸轻屏气作为CTPA扫描的常规呼吸指令。

Objective:To investigate the effect of different breathing instructions on artery enhancement during pulmonary artery CT angiography (CTPA). Methods:A total of 192 patients with suspected pulmonary embolism undergoing CTPA examination were included consecutively and randomly divided into three groups according to different breathing instructions:breath holding after deep inspiration (Group A,84 cases),quiet breathing with slight breath holding (Group B,52 cases) and quiet breathing without breath holding (Group C,56 cases). Same scanning parameters and contrast medium injection were used in all patients. Pulmonary embolism,transient contrast interruption (TIC) or marked respiratory motion artifacts were detected,the image quality was evaluated,the CT values of pulmonary artery trunk were compared among the three groups. Results:There were no significant differences in general data and detecting rate of pulmonary embolism among the three groups (all P>0.05). The incidence of TIC in Group A was higher than that in Group B and C,and the incidence of respiratory motion artifacts in Group C was higher than that in Group A and B (all P<0.017). Image quality in 3 groups met diagnostic requirements,while the image quality in Group A was better than that in Group B and C (both P<0.017). The CT values of pulmonary artery trunk in Group A,B and C were (311.42±77.49),(341.94±82.10) and (345.77±66.16)HU,respectively,with a significant difference (P<0.05). The CT value of pulmonary artery in Group A was lower than that in Group B and C (P<0.05),but there was no significant difference between Group B and Group C (P>0.05). Conclusions:CTPA scanning using quite breathing with slight breath holding or without breath holding can obtain better pulmonary artery enhancement than that using conventional breath holding after deep inspiration. Quiet breathing with slight breath holding can be recommended as a routine breathing instruction for CTPA.