光影摄影创作在实践中的应用

光影摄影,是在夜晚通过相机长时间的曝光,运用摄影手法与技巧记录光在镜头下的变化,最终呈现出肉眼不易观察到的奇妙效果。如何巧妙利用光源,从而在夜间光影摄影作品中发挥更大的创意,本文将从光源的运用、摄影手法与技巧、表现形式三个方面来讨论这个问题。

光与影在产品摄影中的探索与实践

光和影与摄影创作紧密相连,正确认识光线,摸透它的变化规律,结合被摄体的特点,才能巧妙地运用不同特点的光线,创造出优美的画面。文章通过阐述:光影描绘的审美特征;光和影在摄影创作中的重要性;光和影在摄影创作中的运用来说明摄影者既可以通过寻找合适的光与影的组合来定格精彩的瞬间,也可以通过不同的光与影的组合来创作出一幅又一幅优秀的摄影艺术作品。文章将主要围绕光与影在摄影创作中的影响及运用展开探讨,期望可以更加正确的运用光影因素进行摄影创作。

Positron emission tomography/computed tomography with ^(18)F-fluorodeoxyglucose identifies tumor growth or thrombosis in the portal vein with hepatocellular carcinoma

Patients suffering from hepatocellular carcinoma (HCC) with tumor thrombus in the portal vein generally have a poor prognosis. Portal vein tumor thrombus must be distinguished from portal vein blood thrombus, and this identification plays a very important role in management of HCC. Conventional imaging modalities have limitations in discrimination of portal vein tumor thrombus. The application of positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) for discrimination between tumor extension and blood thrombus has been reported in few cases of HCC, while portal tumor thrombosis and portal vein clot identified by 18F-FDG PET/CT in HCC patients has not been reported so far. We present two HCC cases, one with portal vein tumor thrombus and one thrombosis who were identified with 18F-FDG PET/CT. This report illustrates the complimentary value of combining the morphological and functional imaging in achieving a correct diagnosis in such clinical situations.