④回顾性4D CT：自主呼吸下，系统根据呼吸波形低pitch值螺旋扫描，重建出10组相位图。 准确反映相位信息，最后进行 MIP 和Average重建。 综合以上分析，临床实际应用中多以回顾性4D CT为主，目前很多厂家都有4D CT技术，如瓦里安的RPM。

Browse MakeaGif's great section of animated GIFs, or make your very own. Upload, customize and create the best GIFs with our free GIF animator! See it. GIF it. Share it.

Four-dimensional computed tomography (4DCT) is a type of CT scanning which records multiple images over time. It allows playback of the scan as a video, so that physiological processes can be observed and internal movement can be tracked. The name is derived from the addition of time (as the fourth dimension) to traditional 3D computed tomography.

传统3d扫描只能扫描患者某个呼吸时相上的图像，而4d扫描可以根据患者的呼吸扫描全时相，更为准确的评估胸腹部肿瘤运动，具有减小靶区外放，降低放疗副作用等优点。

4DCBCT获取到影像后，可以观察肿瘤的运动情况，主要作用是观察肿瘤的活动度有没有超过照射范围（PTV）。 本质. 4DCT技术的本质，更像是辅助医生给定一个更合适的外放范围（不要太小，否则肿瘤就漏照射了；不要太大，否则正常组织照射过多），也就是保证靶区接受足够剂量照射的同时，尽量减少不必要的照射范围。 复习一下：上一篇介绍了胸腹部加压技术，通过腹压板/腹压带的加压来限制胸腹部的呼吸动度。 概括来说，ABC是深吸气屏气状态下放疗，也就是相 …

Browse MakeaGif's great section of animated GIFs, or make your very own. Upload, customize and create the best GIFs with our free GIF animator! See it. GIF it. Share it.

2016年10月19日 · This data collection consists of images acquired during chemoradiotherapy of 20 locally-advanced, non-small cell lung cancer patients. The images include four-dimensional (4D) fan beam (4D-FBCT) and 4D cone beam CT (4D-CBCT). All patients underwent concurrent radiochemotherapy to a total dose of 64.8-70 Gy using daily 1.8 or 2 Gy fractions.

Figure 4 shows the simulated 10-phase 4D-CT images for a regular respiratory trajectory profile (breathing period: 5 s) (Figure 4 (a)) and an irregular respiratory trajectory of a patient...

Recently, breathing-adapted 4D CT (i4DCT) was introduced into clinical practice, promising artifact reduction in in-silico and phantom studies. Here, we present an image quality comparison study, pooling clinical patient data from two centers: a new i4DCT and a conventional spiral 4D CT patient cohort.

With Tenor, maker of GIF Keyboard, add popular Ct Scan Gif animated GIFs to your conversations. Share the best GIFs now >>>