Clinical evaluation of whole-body oncologic PET with time-of-flight and point-spread function for the hybrid PET/MR system
Clinical evaluation of whole-body oncologic PET with time-of-flight and point-spread function for the hybrid PET/MR system
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DOI：
10.1016/j.ejrad.2017.05.029
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发表时间：
2017-08-01
影响因子：
3.3
通讯作者：
Zhao, Guoguang
中科院分区：
文献类型：
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作者：
Shang, Kun;Cui, Bixiao;Zhao, Guoguang
目的：混合正电子发射断层扫描/磁共振（PET/MR）成像是一种新的多模态成像技术，可以同时提供结构和功能信息。本研究的目的是探讨飞行时间（TOF）和点扩散函数（PSF）对PET/MR图像从临床patient image sets.Materials和Methods中观察到的小病灶的影响：本研究评估了54个小病灶在14例患者谁经历了F-18-氟脱氧葡萄糖（FDG）PET/MR。病变直径达30 mm。PET数据采用基线有序子集期望最大化（OSEM）算法、OSEM + PSF、OSEM + TOF和OSEM + TOF + PSF进行重建。对PET图像质量和小病变进行目视评价，并采用3分制评分。然后使用小病变的平均和最大标准化摄取值（SUV）（SUV平均值和SUV最大值）进行定量分析。根据病变长轴直径和病变部位将病变分为两组，分别采用两种重建算法进行评价。结果：OSEM + TOF + PSF在视觉评价和定量分析中提供了最高值，OSEM + TOF或PSF的视觉评价和定量分析值均高于OSEM。TOF和PSF联合应用使SUV平均值增加26.6%，SUV最大值增加30.0%。SUV（肝脏）不受PSF或TOF的影响。对于OSEM + TOF + PSF模型，直径< 10 mm的病变的SUV平均值和SUV最大值的变化分别为31.9%和35.8%，直径10-30 mm的病变的变化分别为24.5%和27.6%。结论：TOF和PSF技术的应用显著提高了PET/MR混合图像中小病灶的SUV值，提高了小病灶的检出率。
Purpose: Hybrid positron emission tomography/magnetic resonance (PET/MR) imaging is a new multimodality imaging technology that can provide structural and functional information simultaneously. The aim of this study was to investigate the effects of the time-of-flight (TOF) and point-spread function (PSF) on small lesions observed in PET/MR images from clinical patient image sets.Materials and methods: This study evaluated 54 small lesions in 14 patients who had undergone F-18-fluorodeoxyglucose (FDG) PET/MR. Lesions up to 30 mm in diameter were included. The PET data were reconstructed with a baseline ordered-subsets expectation-maximization (OSEM) algorithm, OSEM + PSF, OSEM + TOF and OSEM + TOF + PSF. PET image quality and small lesions were visually evaluated and scored by a 3-point scale. A quantitative analysis was then performed using the mean and maximum standardized uptake value (SUV) of the small lesions (SUVmean and SUVmax). The lesions were divided into two groups according to the long-axis diameter and the location respectively and evaluated with each reconstruction algorithm. We also evaluated the background signal by analyzing the SUVliver.Results: OSEM + TOF + PSF provided the highest value and OSEM + TOF or PSF showed a higher value than OSEM for the visual assessment and quantitative analysis. The combination of TOF and PSF increased the SUVmean by 26.6% and the SUVmax by 30.0%. The SUV(liver)was not influenced by PSF or TOF. For the OSEM + TOF + PSF model, the change in SUVmean and SUVmax for lesions < 10 mm in diameter was 31.9% and 35.8%, and 24.5% and 27.6% for lesions 10-30 mm in diameter, respectively. The abdominal lesions obtained the higher SUV than those of chest on the images with TOF and/or PSF.Conclusion: Application of TOF and PSF significantly increased the SUV of small lesions in hybrid PET/MR images, potentially improving small lesion detectability.