摘要目的:TOF-PET(Time of flight-positron emission tomography,TOF-PET)和PSF-PET(Point spread function-PET,PSF-PET)是用于提高PET性能的最新技术。本研究目的是比较TOF-PET和PSF-PET对脑、肝脏正常组织以及胸腹部肿瘤病灶组织对18F-FDG标准摄取率最大值(Standard uptake value maximum,SUVmax)的影响。以指导临床更好使用TOF-PET和PSF-PET技术。材料和方法:35例患者(男19例,女16例,年龄(58.69±12.88)岁),体质量指数(BMI)25.18±4.32。35例患者肺部病灶29个,腹部12个。CT测量病灶直径范围5~40 mm。使用GE Discovery PET/CT Elite和AW工作站。选择SharpIR+VUE Point HD,TOF+VUE Point HD 和SharpIR+VUE Point HD+TOF重建PET图像。SharpIR和VUE Point HD是分别PSF和迭代重建的商品名。结果:TOF与非TOF比较,胸部、腹部病灶SUVmax分别提高7.1%(n=29,P<0.001)、5.54%(n=12,P<0.006)。BMI>25组TOF与非TOF相比较,胸部、腹部病灶SUVmax分别提高15.6%(n=12,P<0.001)和20.6%(n=4,P<0.035)。同一组病灶(n=6)采用VUE HD+SharpIR、VUE HD+TOF、VUE HD+SharpIR+TOF处理后与VUE HD相比较,SUVmax分别提高了17.69%、2.3%和22.54%。对于所有病灶、脑正常组织,TOF-PET和PSF-PET均能提高SUVmax,但是对于BMI>25的病灶,TOF-PET提高SUVmax更明显。PSF-PET与TOF-PET相比较,PSF-PET对SUVmax提高的幅度明显大于TOF-PET。肝脏正常组织受TOF-PET技术影响并不明显。讨论:TOF-PET和PSF-PET均能提高病灶和脑正常组织的SUVmax,但是PSF-PET优于TOF-PET。对于BMI>25的患者的胸部、腹部病灶,TOF-PET技术对病灶SUVmax的提高更为显著。
Abstract:Objective: TOF-PET(Time of flight-positron emission tomography, TOF-PET) and PSF-PET (Point spread function-PET, PSF-PET) were used to improve the PET performance of the latest technology. The purpose of this study was to compare TOF-PET and PSF-PET on normal tissue of brain, liver, as well as the thoracic and abdominal tumor lesions on 18F-FDG standard uptake value maximum(SUVmax) effect, so that to guide the clinical use of TOF-PET and PSF-PET technique better. Materials and methods: Thirty-five patients(male 19, female 16 cases, age 58.69±12.88 years old) with BMI 25.18±4.32 were studied. The 35 patients had 29 pulmonary lesions and 12 abdominal lesions. CT measurement of lesion diameter was in the range of 5~40 mm. GE Discovery PET/CT Elite and AW workstation was used. The SharpIR+VUE Point HD, TOF+VUE Point HD and SharpIR+VUE Point HD+TOF reconstruction method of PET images were selected. SharpIR and VUE Point HD were commercial names for PSF and iterative reconstruction respectively. Results: Compared with NO-TOF reconstruction SUVmax value of chest and abdominal lesions with TOF were increased by 7.1%(n=29, P<0.001) and 5.54%(n=12, P<0.006). In the group of BMI>25, SUVmax values of chest and abdominal lesions with TOF increased by 15.6%(n=12, P<0.001) and 20.6%(n=4, P<0.035) compared with NO-TOF. For the same group of lesions(n=6), SUVmax value by VUE HD+SharpIR, VUE HD+TOF, VUE HD+SharpIR+TOF were increased by 17.69%, 2.3%, 22.54% compared with VUE HD. For all the lesions and normal brain tissue, SUVmax values were increased by both TOF-PET and PSF-PET, but for patients with BMI greater than 25 lesions, TOF-PET raised SUVmax more obviously. Compared with TOF-PET, PSF-PET enhanced SUVmax more significantly than TOF-PET. Normal liver tissue was not affected by TOF-PET technology. Conclusion: Our results indicate that TOF-PET and PSF-PET can improve the brain lesions and normal tissue SUVmax, but PSF-PET is superior to TOF-PET. For the patients with BMI greater than 25, TOF technology increases the SUVmax value of chest and abdominal lesions more obviously.