128层螺旋CT前门控技术在小儿复杂性先天性心脏病中的应用

Application of prospectively electrocardiograph-gated 128-slice spiral CT angiography in children with complex congenital heart disease

目的探讨128层CTA前门控技术在小儿复杂先天性心脏病（CHD）诊断中的价值。方法选取复杂CHD患儿80例，根据就诊时间先后分别采用后、前门控技术行128层CTA检查，每组各40例，所有患儿在CTA检查前1周内均行心脏超声心动图（UCG）检查。采用独立样本t检验和x。检验对图像的有效辐射剂量和质量进行统计分析；以手术结果为诊断标准，采用）（2检验将术前CTA前、后门控扫描组与UCG诊断结果进行对照研究。结果前门控组的有效辐射剂量[（1．00±0．26）mSv]较后门控组[（7．37±0．52）mSv]降低了86％，差异有统计学意义（t=69．296，P〈0．01）。图像质量评估前、后门控2组：0级均为0例，1级分别为2和0例，2级分别为8和1例，3级分别为30和39例，2组间差异无统计学意义（X2=0．044，P〉0．05）。前、后门控组CTA在心外大血管畸形诊断符合率分别为98．3％（59／60）和98．3％（58／59），明显优于UCG[分别为76．7％（46／60）、76．7％（45／59）]，差异有统计学意义（x2值分别为13．144、12．644，P值均〈0．01），但前、后门控组间差异无统计学意义（）（。=0．001，P〉0．05）。前、后门控组CTA对心脏大血管连接异常诊断符合率均为100．0％，与UCG[分别为97．2％（35／36）、97．3％（36／37）]比较，差异无统计学意义（x2值分别为1．014、0．001，P值均〉0．05）。前、后门控组CTA对心内畸形诊断符合率分别为88．7％（47／53）和92．5％（49／53），与UCG[分别为98．1％（52／53）、98．1％（52／53）]比较，差异无统计学意义（x。值分别为3．824、1．889，P值均〉0．05），前、后门控组间差异也无统计学意义（x2=0．442，P〉0．05）。同时，MSCTA能观察所有患儿肺部情况，前、后门控2组共检出合并气道异常9例。结论128层CTA前门控技术在小儿复杂CHD术前诊断中具有很高的临床应用价值，有助于手术方案的制定和手术风险的评估。

Objective To evaluate the prospective electrocardiograph （ECG）-gated 128-slice spiral CT angiography in the diagnosis of complex congenital heart disease and airway abnormality in children. Methods Eighty children with congenital heart disease received prospective （n = 40 ） or retrospective ECG-gated 128-slice spiral CT angiography （n = 40）. All of the patients underwent ultrasound cardiogram （UCG） within one week before CTA exmination. The image quality and the effective radiation dose were statistically analyzed using independent samples t test and X2 test. The surgical results were taken as the diagnostic standards, and the preoperative prospective and retrospective CT angiography data were compared with UCG results using X~ test. Results The effective dose of prospective ECG-gated CT angiography[ （1.00 ±0. 26）mSv] was reduced by 86% as compared with the retrospective ECG-gated CT angiography[ （7.37 ±0. 52） mSv] （t =69. 296,P 〈0. 01 ）. Image quality was graded 0 in none patients, graded 1 in 2 patients who underwent prospective ECG-gated CT angiography, graded 2 in 8 and 1 patient who received prospective and retrospective ECG-gated CT angiography respectively, and graded 3 in 30 and 39 patients who underwent prospective and retrospective ECG-gated CT angiography, respectively. There was no significant difference in image quality between prospective and retrospective ECG-gated CT angiography （X2 = 0. 044, P 〉 0. 05 ）. The definitive diagnosis of extracardiac vascular anomalies was made in 98.3%（59/60） of patients by using prospective and retrospective ECG-gated CT angiography, which were significantly superior to UCG results[ （76.7% （46/60） ,76.7% （45/59） , respectively] （X2 = 13. 144, 12. 644, P 〈 0. 01 ）, and there was no significant difference in the definitive diagnosis between prospective and retrospective ECG-gated CT angiography （ x2 = 0. 001, P 〉 0. 05 ）. The definitive diagnosis of the cardiac/large-vessel malformations was made in 100% of the patients by both prospective and retrospective ECG-gated CT angiography, and there was no significant difference between 128-slice spiral CT angiography results and UCG results [ 97. 2% （35/36）, 97. 3% （36/37） , respectively ] （ x2 = 1. 014, 0. 001, P 〉 0. 05 ）. In the cardiac malformations, the definitive diagnosis by prospective and retrospective ECG-gated CT angiography was 88.7% （47/53） and 92. 5% （49/53）, and there was no significant difference between 128- slice spiral CT angiography results and UCG results [ 98. 1% （ 52/53 ）, 98.1% （ 52/53 ）, respectively ] （ X2= 3. 824, 1. 889, P 〉 O. 05 ） , and no significant difference in the definitive diagnosis was observed between prospective and retrospective ECG-gated CT angiography （ X2= 0. 442, P 〉 0. 05 ）. In addition, the 128-slice spiral CT angiography detected airway abnormality in 9 cases who underwent prospective or retrospective ECG-gated CT angiography. Conclusion The prospective ECG-gated 128-slice spiral CT angiography exhibits great application value in the preoperative diagnosis of complex congenital heart disease, which helps to develop surgical program and evaluate surgical risks.