Vetter S, Heckmann H, Strecker E P, Busch H P, Kamm K F, Allmendinger H
Abteilung Röntgendiagnostik und Nuklearmedizin, Diakonissenkrankenhaus, Karlsruhe.
Aktuelle Radiol. 1998 Jul;8(4):191-5.
The relations between image quality in last image hold images and dose in grid controlled fluoroscopy in comparison to the continuous mode need to be characterised and recommendations for the clinical application of this technique should be given.
Spatial resolution, signal-noise ratio and, contrast-detail visibility were evaluated by phantom measurements in grid controlled pulsed and continuous fluoroscopy. Dose was measured at the image intensifier entrance. Image quality of last image hold (LIH) images of clinical examinations was graded in relation to single shot exposures.
Signal-noise ratio and contrast-detail visibility depend on the dose per puls. Spatial resolution and contrast-detail visibility in grid controlled fluoroscopy are superior than to in the continuous mode. Image quality of the LIH images from the grid controlled fluoroscopy was improved. Radiation exposure could be reduced to 10-46%.
Combinations of puls-dose and -frequency are recommended for achieving extensive dose reduction and improved image quality of LIH images.
与连续模式相比，需明确格栅控制荧光透视中末次图像保持图像的图像质量与剂量之间的关系，并给出该技术临床应用的建议。
通过在格栅控制脉冲和连续荧光透视中使用模体测量来评估空间分辨率、信噪比和对比细节可见度。在影像增强器入口处测量剂量。根据单次曝光对临床检查的末次图像保持（LIH）图像的图像质量进行分级。
信噪比和对比细节可见度取决于每脉冲剂量。格栅控制荧光透视中的空间分辨率和对比细节可见度优于连续模式。格栅控制荧光透视的LIH图像的图像质量得到改善。辐射暴露可降低至10 - 46%。
建议采用脉冲剂量和频率的组合，以实现大幅剂量降低并改善LIH图像的图像质量。
