排序方式： 共有3条查询结果，搜索用时 62 毫秒
1
1.
Objectives: To directly compare the quality of harmonic imaging (HI) and fundamental imaging (FI) in fetal echocardiography and to determine any differences in image quality between the two modalities. Methods: Fetal echocardiograms were performed with the use of FI and HI in 58 fetuses, image quality and visualization of left and right atria, left and right ventricles, mitral and tricuspid valves, aortic and pulmonary valves, left and right ventricular outflow tracts were evaluated and compared between FI and HI. Results: Mean HI scores were higher than mean FI scores (2.73±0.43 vs 2.16±0.69, P<0.001)for all the cardiovascular structures evaluated. Compared with FI, HI improved the image quality and visualization of fetal cardiac structures in subjects with both good (2.73±0.43 vs 2.88±0.32, P<0.001) and suboptimal (1.65±0.41 vs 2.58±0.47, P<0.001) echocardiographic windows. The interobserver correlation coefficient for the grading scores was 0.74 (P<0.001). Conclusions: harmonic imaging enhances and improves the image quality of fetal echocardiography; and has important potential role in cardiac imaging in the fetus. 相似文献
2.
INTRODUCTIONHarmonicimaging (HI)isoneofthemostimportantultrasoundimagingproceduresdevel opedrecently,differingfromfundamentalimag ing (FI)bytransmittingultrasoundatonefre quencyandreceivingitattwoormoretimesthetransmittedfrequency .Clinicalapplicationshad… 相似文献
3.
重庆市乡村旅游运营效率评价与空间战略分异研究 总被引：3，自引：0，他引：3
基于重庆市38个区县2014年乡村旅游运营资本投入、劳动力投入、乡村旅游资源投入数据和农村经济效益、社会效益和环境效益产出数据,综合运用超效率SBM模型与ArcGIS空间分析平台,考察分析重庆38个评价单元乡村旅游运营效率及其空间分异,并回溯刻画了各评价单元效率损失主导因素及空间差异。研究发现：①从效率数理特征来看,重庆乡村旅游发展仍处于初级阶段,且呈现资本、劳动力与服务机构投入不足状态;②从效率空间分异特征来看,都市功能区已处于规模效益递减阶段,且普遍存在由于投入过量而导致的效率损失,渝东北、渝东南地区仍处于规模效益递增阶段,且普遍存在由于投入不足而导致的效率损失,主城近郊、渝西、渝东地区普遍存在由于非期望产出过量而导致的效率损失。在上述研究基础上,根据市域乡村旅游运营效率及其损失的空间分异,提出了“一核一圈两翼七大板块”的乡村旅游空间战略格局优化方案,并构建了差别化发展策略。 相似文献
1