基于原始数据的迭代重建技术在眼眶CT平扫中的应用

目的 探讨基于原始数据的迭代重建(SAFIRE)技术在眼眶CT平扫中的价值。方法 对50例眼部外伤患者行眼眶CT平扫,分别采用用滤过反投影(FBP)和SAFIRE(强度1~5级)技术重建图像;对比分析6种重建图像的平均CT值、噪声、SNR、CNR、图像质量评分及病变检出率。结果 6种重建图像间,同种组织CT值差异无统计学意义(P均>0.05);与FBP图像相比,1~5级SAFIRE图像中视神经噪声分别降低15.69%、27.39%、36.17%、41.75%和53.99%,视神经SNR分别提高18.62%、37.46%、55.70%、69.55%和118.11%,CNR分别提高21.59%、32.90%、56.43%、83.91%和104.39%(P均<0.05);SAFIRE 1级和 5级图像的质量评分低于FBP图像,2~4级图像的质量评分高于FBP图像,SAFIRE 3级图像评分最高。结论 眼眶CT平扫中应用SAFIRE能有效降低噪声和提高图像质量。

Application of sinogram affirmed iterative reconstruction technique in orbital CT scan

Objective To investigate the value of sinogram affirmed iterative reconstruction (SAFIRE) technique in orbital CT scan. Methods Totally 50 ocular trauma patients underwent orbital CT scan, and six groups images were reconstructed with FBP and SAFIRE (strength grade 1-5). CT value, noise, SNR, CNR, image quality scoring and lesion detection rate among FBP and SAFIRE images were compared. Results There was no difference among 6 groups reconstructed images on CT value of the same tissue (P>0.05). Compared with FBP image, noises of optic nerve in SAFIRE 1-5 image decreased by 15.69%, 27.39%, 36.17%, 41.75% and 53.99%, SNR of optic nerve increased by 18.62%, 37.46%, 55.70%, 69.55% and 118.11%, while CNR increased by 21.59%, 32.90%, 56.43%, 83.91% and 104.39%, respectively (all P<0.05). Quality scores of SAFIRE 1 and SAFIRE 5 image were lower, while SAFIRE 2-4 image were higher than that of FBP, and the score of SAFIRE 3 image was the highest. There was no obvious difference among all the images on the rate of lesion detection. Conclusion SAFIRE can effectively decrease the image noise and increase the image quality in orbital CT scanning.