CAJ | 학술논문

目的探讨Philips GEMINI PET/CT五种常规图像重建算法对PET图像质量的影响.方法对Jaszack模型进行PET/CT显像,分别运用滤波反投影Hanning滤波(FBP-Hanning)、滤波反投影Butterworth滤波(FBP-Butterworth)、有序子集最大期望值法(OSEM)、行处理最大拟然算法(RAMLA)及三维行处理最大拟然算法(3D-RAMLA)对模型显像的各组原始数据进行图像重建.比较模型显像在不同重建算法及不同计数状态时图像分辨率、图像均匀性、图像对比度以及重建时间的差异.结果模型显像中,3D-RAMLA、RAMLA、OSEM、FBP-Hanning及FBP-Butterworth所需重建时间分别为180 s、130 s、120 s、85 s、80 s.在高计数状态下,FBP-Butterworth最小可分辨4.8 mm的"热区"立柱,FBP-Hanning、OSEM、RAMLA及3D-RAMLA最小可分辨6.4 mm的"热区"立柱.在各种重建算法中,3D-RAMLA的图像对比度明显优于其他算法,RAMLA及3D-RAMLA的图像均匀性指标优于其他算法.随着采集计数的减少,各重建算法均出现图像分辨率、图像均匀性以及图像对比度的下降,其中以FBP-Butterworth下降最为显著.结论不同重建算法及不同计数状态下PET图像质量存在不同程度的差异,在临床显像中应根据需要选择适当的图像重建算法.
목적 탐토Philips GEMINI PET/CT오충상규도상중건산법대PET도상질량적영향.방법 대Jaszack모형진행PET/CT현상,분별운용려파반투영Hanning려파(FBP-Hanning)、려파반투영Butterworth려파(FBP-Butterworth)、유서자집최대기망치법(OSEM)、행처리최대의연산법(RAMLA)급삼유행처리최대의연산법(3D-RAMLA)대모형현상적각조원시수거진행도상중건.비교모형현상재불동중건산법급불동계수상태시도상분변솔、도상균균성、도상대비도이급중건시간적차이.결과 모형현상중,3D-RAMLA、RAMLA、OSEM、FBP-Hanning급FBP-Butterworth소수중건시간분별위180 s、130 s、120 s、85 s、80 s.재고계수상태하,FBP-Butterworth최소가분변4.8 mm적"열구"립주,FBP-Hanning、OSEM、RAMLA급3D-RAMLA최소가분변6.4 mm적"열구"립주.재각충중건산법중,3D-RAMLA적도상대비도명현우우기타산법,RAMLA급3D-RAMLA적도상균균성지표우우기타산법.수착채집계수적감소,각중건산법균출현도상분변솔、도상균균성이급도상대비도적하강,기중이FBP-Butterworth하강최위현저.결론 불동중건산법급불동계수상태하PET도상질량존재불동정도적차이,재림상현상중응근거수요선택괄당적도상중건산법.
Objective To evaluate the effects of different reconstruction algorithms on image quality for Philips GEMINI PET/CT. Methods Jaszczak phantom were scanned on the GEMINI PET/CT system, and the raw data were reconstructed using filtered-back projection with Hanning filter (FBP-Hanning), filtered-back projection with Butterworth filter (FBP-Butterworth), ordered subset expectation maximization (OSEM), row-action maximum likelihood algorithm (RAMLA) and three-dimensional row-action maximum likelihood algorithm (3D-RAMLA), respectively. The resolution, uniformity, contrast of images and the time of different reconstruction algorithms were compared. Results The reconstruction time was 180 s, 130 s, 120 s, 85 s and 80 s for 3D-RAMLA, RAMLA, OSEM, FBP-Hanning and FBP-Butterworth respectively in phantom studies. The smallest rods with diameter of 4.8 mm of the phantom could be observed for FBP- Butterworth and 6.4 mm for other algorithms in case of high counts. The image contrast of 3D-RAMLA were better than that other algorithms, and the image uniformity of 3D-RAMLA and RAMLA were better than those of other algorithms. The resolution, uniformity and contrast of images with all algorithms decreasd in case of low counts, and the image quality of FBP-Butterworth was not good enough for clinical studies. Conclusion Image quality is variable with different reconstruction algorithms. For clinical PET imaging, it is necessary to choose proper algorithms.