OCTA对青少年近视人群视网膜微血管密度的观察

目的：基于光学相干断层扫描血管成像（OCTA）技术探讨青少年儿童近视与视网膜表层微血管密度 及视网膜厚度的相关性。方法：横断面研究。共纳入2018年5─11月于四川大学华西医院眼科门 诊就诊的7～14岁青少年近视患者105例（193眼）。对所有受检者进行光学相干断层扫描（OCT）和 OCTA检查，量化分析黄斑中心凹视网膜厚度和各部位视网膜表层微血管密度。单因素方差分析比 较低、中、高度近视组各部位视网膜微血管密度及视网膜厚度的差异。采用Pearson相关系数探讨视 网膜厚度与各部位视网膜表层微血管密度的相关性。Spearman相关系数用于探讨等效球镜与中心凹、 旁中心凹视网膜表层微血管密度以及视网膜厚度的关系；分段多项式函数分析等效球镜度与外环及 直径6 mm完整视网膜表层微血管密度的关系。结果：旁中心凹、外环、直径6 mm完整区域视网膜 表层微血管密度在低、中、高度近视组间比较差异均具有统计学意义（F=11.651、14.499、14.232， 均P<0.001）。年龄与中心凹视网膜厚度之间有较弱正相关关系（r=0.187，P=0.011），与各部位微血管 密度均无相关性。等效球镜度与旁中心凹视网膜微血管密度有相关性（r=-0.301，P<0.001），与外环、 直径6 mm完整区域视网膜表层微血管密度呈曲线相关（r=-0.319，P<0.001；r=-0.307，P<0.001）。 但与中心凹视网膜表层微血管密度及视网膜厚度无显著相关性。此外，中心凹处视网膜厚度与微血 管密度呈正相关（r=0.691，P<0.001），与其余部位微血管密度无相关性。结论：青少年近视程度数 与旁中心凹、外环及直径6 mm完整区域视网膜表层微血管密度呈负相关；中心凹处视网膜厚度与年 龄、微血管密度呈正相关。     

Left ventricular and atrial strain imaging with cardiac computed tomography: Validation against echocardiography

BackgroundData on left ventricular (LV) deformation imaging using CT angiography (CTA) are scarce and the feasibility of atrial deformation analysis by CT has not been addressed. We aimed to compare 2D echocardiographic and CT derived LV and left atrial (LA) global longitudinal strain (GLS) obtained by using a novel feature tracking algorithm in patients following transcatheter aortic valve implantation.MethodsTwenty-eight patients were included who underwent retrospectively-gated 256-slice CTA and speckle-tracking echocardiography (STE) on the same day. CT datasets in 10% increments were reconstructed throughout the cardiac cycle. LV GLS and LA global peak reservoir strain (LA GS) was measured.ResultsMedian absolute values for LV GLS were 19.9 [14.8–22.4] vs. 19.9 [16.8–24.7], as measured by CT vs STE, respectively (p = 0.017). We found good inter-modality correlation for LV GLS (ρ = 0.78, p < 0.05) with a mean bias of −1.6. Regarding atrial measurements, the median LA GS was 19.0 [13.5–27.3] for CT vs. 28.0 [17.5–32.6] for STE (p < 0.001) with a mean bias of −5.6 between CT and STE and a correlation coefficient of ρ = 0.87, p < 0.001. CT measurements were highly reproducible: intra-observer intra-class correlation coefficient was 0.96 for LV GLS and 0.95 for LA GS.ConclusionWe detected good correlation between CTA and echocardiography-based LV and LA longitudinal strain parameters. CTA provides accurate strain measurements with high reproducibility. Feature tracking-based deformation analysis could provide a clinically important addition to CT examinations by complementing anatomical information with functional data.