Objective To observe the value of self-made self-coagulating denture power helmet for PET/CT scanning of adult rats.Methods Eleven adult healthy male SD rats with body weight of 290-300 g were selected.Taken 1 rat's head as a reference,a self-made helmet with a thickness of 2 mm was obtained using self-coagulating denture powder to fix the rat's head.Then the other 10 rats were randomly divided into group A and group B(each n=5).The heads of rats were fixed with helmets,and 18F-FDG PET(scanning time 20 min)and CT images were acquired.Pain models were constructed using rats in group B through injection of 5％formaldehyde solution 0.10 ml at the right foot at the 11th minute during PET collection.The imaging quality of 18F-FDG PET/CT in group A was observed,and CT gray values of the olfactory bulb covered by helmet and soft tissue area posterior occipital region without helmet coverage in group A were compared.The quality of PET images before and after pain induction in group B were analyzed to evaluate the fixation effect of helmet.Based on PET images,the changes of 18F-FDG standard uptake value ratio(SUVR)in primary somatosensory cortex hindlimb region(S1HL)in group B after pain induction were observed.Results PET and CT images in group A were clear,with no obvious foreign body artifacts.CT gray values of olfactory bulb and soft tissue in posterior occipital region in group A was 257.0±50.7 and 194.4±55.4,respectively,being not significantly different(P=0.054).PET images before and after pain induction in group B showed no obvious artifacts,and the continuity between covered area of helmet and non-covered area was good.After pain induction,S1HL on the contralateral side of pain induction in group B significantly activated.The ratio of SUVRafter pain induction/SUVRbefore pain induction in S1HL on the contralateral side of pain induction was 1.19±0.07,and SUVRafter pain induction was higher than SUVRbefore pain induction(P=0.001).Conclusion Self-made self-coagulation denture powder helmet could effectively fix head of adult rat during PET/CT scanning.

Objective To observe the value of self-made self-coagulating denture power helmet for PET/CT scanning of adult rats.Methods Eleven adult healthy male SD rats with body weight of 290-300 g were selected.Taken 1 rat's head as a reference,a self-made helmet with a thickness of 2 mm was obtained using self-coagulating denture powder to fix the rat's head.Then the other 10 rats were randomly divided into group A and group B(each n=5).The heads of rats were fixed with helmets,and 18F-FDG PET(scanning time 20 min)and CT images were acquired.Pain models were constructed using rats in group B through injection of 5％formaldehyde solution 0.10 ml at the right foot at the 11th minute during PET collection.The imaging quality of 18F-FDG PET/CT in group A was observed,and CT gray values of the olfactory bulb covered by helmet and soft tissue area posterior occipital region without helmet coverage in group A were compared.The quality of PET images before and after pain induction in group B were analyzed to evaluate the fixation effect of helmet.Based on PET images,the changes of 18F-FDG standard uptake value ratio(SUVR)in primary somatosensory cortex hindlimb region(S1HL)in group B after pain induction were observed.Results PET and CT images in group A were clear,with no obvious foreign body artifacts.CT gray values of olfactory bulb and soft tissue in posterior occipital region in group A was 257.0±50.7 and 194.4±55.4,respectively,being not significantly different(P=0.054).PET images before and after pain induction in group B showed no obvious artifacts,and the continuity between covered area of helmet and non-covered area was good.After pain induction,S1HL on the contralateral side of pain induction in group B significantly activated.The ratio of SUVRafter pain induction/SUVRbefore pain induction in S1HL on the contralateral side of pain induction was 1.19±0.07,and SUVRafter pain induction was higher than SUVRbefore pain induction(P=0.001).Conclusion Self-made self-coagulation denture powder helmet could effectively fix head of adult rat during PET/CT scanning.