肺灌注显像在紫绀型先心病血液分流中的应用

目的 利用放射性肺灌注显像对紫绀型先天性心脏病进行分流定量分析,探讨其与缺氧的关系。方法22例右向左分流的复杂型先天性心脏病行肺灌注显像;以脑、肾放射性指数（NPI）对分流定量;将肺放射性指数（PI）与血红蛋白（Hb）、红细胞（RBC）及血氧饱和度（SaO2）进行相关分析。结果 NPI和PI呈显著负相关（r=-0.95,P<0.01）;PI与Hb及RBC均呈显著负相关（r分别为-0.55和-0.58,P均<0.01）;PI与SaO2呈显著相关（r=0.83,P<0.01）。轻一中度及轻一重度PI组间的Hb有显著差异（t分别为2.8和3.8,P均<0.05）,而中一重度PI组别间的Hb无显著差异（t=0.5,P<0.05）结论　NPI可直接反映紫绀型先天性心脏病的右向左分流量。分流量越大,缺氧越严重;SaO2越低,Hb及RBC越高。但缺氧达一定程度后,两者的升高不能准确反映机体的缺氧状态。

The Evaluation of Lung Perfusion Imaging in the Shunt Application of the Cyanotic Congenital Heart Disease

Objective To quantify the shunt of cyanotic congenital heart disease(CHD) by lung perfusion imaging, and evaluate the relationship between the shunt and anoxemia. Methods Lung perfu-sion imaging with 99mTc - MAA was performed in 22 CHD patients with a right - to-left shunt to quantify the shunt by means of the brain and kidney index(NPI) and compare the pulmonary index( PI) with Hb and RBC respectively, as well as compare the Hb values in different PI groups. Results NPI was markedly related with PI(r=-0.95,P<0.01); PI was correlated well with Hb, RBC and SaO2 ( r =-0. 55,r=-0.58, r =0. 83 ,Pall <0. 01 ) . There were significant differences of Hb values in the mild - moderate group and in the mild - severe group(t=2. 8, t=3.8, Pall<0.05), but no significant difference between moderate - severe group (P >0. 05). Conclusions NPI can demonstrate the amount of right - to - left shunt in cyanotic CHD. The more the shunt, the more severe the anoxemia, and the lower the SaO2. Hb and RBC also increase with the shunt, but they will not represent the exact degree of anoxemia after approaching to a certain high level.