一种用于全身照射技术的全身模拟定位CT扫描与图像重建方法

目的：探索一种适用于全身照射（TBI）的CT重建方法，可同体位连续扫描后获得一套完整的全身模拟定位CT。方法：使用TBI CT重建方法对患者进行CT模拟定位，完成后于Eclipse v15.5计划系统中生成一套全身模拟定位CT，将其运用到TBI计划设计与评估。在应用过程中，基于Python系统开发出相应的图像重建软件，与手动图像重建结果进行对比。结果：该全身模拟定位扫描方案可在Eclipse v15.5中实现两套CT的重建。在工作效率上，手工重建方法生成全身模拟定位CT平均需要10 min，软件重建方法只需要5 s。两种CT重建方法在图像质量上无差异，重建CT与真实值相比误差小于1 mm。使用重建的全身模拟定位进行TBI计划设计与评估，靶区适形度指数（CI）=0.854，剂量均匀性指数（HI）=0.199。结论：本文介绍的TBI全身模拟定位CT扫描与图像重建的方法可以简单、快速地获得完整的全身模拟定位CT图像，适用于后期的TBI计划设计、优化和评估过程。

Total-body CT simulation and image reconstruction method for total-body irradiation

Abstract: Objective To explore a CT reconstruction method suitable for total-body irradiation (TBI), which can obtain a complete set of total-body CT images after continuous scanning at the same posture. Methods After CT simulation positioning using the TBI CT reconstruction method, a set of total-body CT images was generated in Eclipse v15.5 system, and it was applied to TBI planning and plan evaluation. Meanwhile, the corresponding image reconstruction software was developed based on Python system, and the reconstruction results were compared with manual image reconstruction results. Results The scanning protocol for the total-body simulation and positioning completed the reconstruction of two sets of CT images in Eclipse v15.5. The manual reconstruction method took 10 min on average to generate each set of total-body CT images, while the software only took 5 s. The image quality between the two CT image reconstruction methods did not differ significantly, and the error between the reconstructed CT and the real value was less than 1 mm. The TBI plan was formulated based on the reconstructed whole-body CT, and the plan evaluation showed that the conformity index and homogeneity index of target area were 0.854 and 0.199, respectively. Conclusion The total-body CT simulation and image reconstruction method for TBI can obtain a complete set of total-body CT images simply and quickly, which is suitable for the later TBI planning, optimization and evaluation.