Application Of The Flash DSCT In The Assessment Of The Pulmonary Valve And Pulmonary Arteries In Congenital Heart Disease With Diminished Pulmonary Blood Flow

Part one Flash no ECG-gated versus prospective ECG-triggering the flash dual-source CT imaging in the diagnosis of pulmonary valve and pulmonary arteryObjective:To evaluate the dual-source CT imaging in the diagnosis of pulmonary valve and pulmonary artery with congenital heart diseases.Methods:We retrospectively evaluated90dual-source CT images that were obtained using two different protocols (Flash helical no ECG-gated [n=45] versus Prospective non-helical ECG-triggering [n=45]) in patients with congenital heart disease younger than13years old. Two radiologists evaluated the image quality, using a3-or-5point scale,in terms of the subjective image contrast, the visualization of the pulmonary valve,the degree of homogeneity of vascular enhancement, the stair-step artifacts.The objective image noise (standard deviation of attenuation) was calculated. We compared the mean score of image quality and the estimated radiation dose. P value<0.05was considered to indicate a significant difference.Results:The overall image quality in the both groups meet the diagnostic requirements of congenital heart disease. The mean score of the image contrast and the visualization of the pulmonary valve in the prospcetive group was better than those scores in the flash group (P<0.05).The mean scores of the stair-step artifacts and the homogeneity of vascular enhancement in the flash group were better than those scores in the prospcetive group (P<0.05). As a parameter of objective image noise,the mean standard deviation of attenuation in the prospcetive group was lower than that in the flash group (19.25±4.42vs.15.80±2.29,P<0.05). the mean estimated effcetive dose was higher for the prospcetive ECG-gated scan than that for the flash no ECG-gated helieal scan(0.45vs.0.19mSv respectively, P<0.001).Conclusion:1. Flash no ECG-gated and Prospective ECG-triggering CTA can effectively reduce the infant and childrens’radiation dose without compromising image quality. But the radition dose of Flash no ECG-gated scan is lower than that of Prospective ECG-triggering2. Flash no ECG-gated scan cannot better visualize the pulmonary valve, so we recommend the Prospective ECG-triggering scan in infant and children with pulmonary valve stenosis. Part two Application prospective ECG-triggering of the flash DSCT in the assessment of the pulmonary valve and pulmonary arteries in congenital heart disease with diminished pulmonary blood flowObjective:To investigate the clinical value of DSCT with prospective ECG-triggering mode preoperation in the assessment of pulmonary valve and the pulmonary arteries in congenital heart disease with diminished pulmonary blood flow and compared with echocardiography.Methods:40patients suspected or definited congenital heart disease with diminished pulmonary blood flow were examined by DSCT with prospective ECG-triggering.Original data were reconstructed in5%steps throughout the30-90%R-R interval to observe the leaflet munber and shape of the pulmonary valve.The valve ring were concerned at the image of end-systole. At the image of end-systole,5aspects reflecting Pulmonary artery developmental capacity were concerned, including the pulmonary artery trunk,left pulmonary artery, right pulmonary artery, descending aorta at the diaphragma level, McGoon index, whose results were subjected to statistical analysis using Pearson’s correlation and t-test analysis compared with that of echocardiography.Results:The leaflet number and shape of the pulmonary valve could be clearly observed from the multi-planar reconstruction image and multi-stage reconstruction image.There were significant difference between DSCT and TTE for the noninvasive assessment of leaflet munber of the pulmonary valve (P<0.05). The pulmonary arterier could be clearly observed from original images and reconstruction images. There were no significant difference between DSCT and TTE (P>0.05), but signifieant difference for the diagnosis of aortopulmonary collateries (P<0.05). The measurement parameters,including the valve ring,the pulmonary artery trunk,left pulmonary artery, right pulmonary artery and the McGoon index,correlating well with each other by DSCT and TTE,and there were no significant difference between each other by DSCT and TTE (P>0.05).Conclusion:The flash DSCT with prospective ECG-triggering mode can clearly display the leaflet number and shape of the pulmonary valve.There were no significant difference between DSCT and TTE for measuring the valve ring, and pulmonary arteries.DSCT is superior to TTE on the display of aortopulmonary collateries.Therefore it would be helpful to evaluate the pulmonary valve and the pulmonary arteries development condition preoperation of congenital heart disease with diminished pulmonary blood flow.