Evaluation of PET Mainstream Scattering Correction Methods / 中国医疗器械杂志

OBJECTIVE@#Current mainstream PET scattering correction methods are introduced and evaluated horizontally, and finally, the existing problems and development direction of scattering correction are discussed.@*METHODS@#Based on NeuWise Pro PET/CT products of Neusoft Medical System Co. Ltd. , the simulation experiment is carried out to evaluate the influence of radionuclide distribution out of FOV (field of view) on the scattering estimation accuracy of each method.@*RESULTS@#The scattering events produced by radionuclide out of FOV have an obvious impact on the spatial distribution of scattering, which should be considered in the model. The scattering estimation accuracy of Monte Carlo method is higher than single scatter simulation (SSS).@*CONCLUSIONS@#Clinically, if the activity of the adjacent parts out of the FOV is high, such as brain, liver, kidney and bladder, it is likely to lead to the deviation of scattering estimation. Considering the Monte Carlo scattering estimation of the distribution of radionuclide out of FOV, it's helpful to improve the accuracy of scattering distribution estimation.

Promoting effects of Guavenoic acid (GA)on proliferation,insulin synthesis and secretion in INS-1 cells and their mechanism / 中国药理学通报

Aim To investigate the effects of Guaveno-ic acid (GA)on proliferation,insulin synthesis and secretion in INS-1 cells and their possible mechanism. Methods INS-1 βcells were cultured in vitro.Control group,medium group,model group,drug groups and positive group were set.INS-1 cells were treated with GA (0.3,1 ,3,1 0,30 nmol·L -1 )for 48 h.The cell proliferation was tested by MTT assay.Acid-alco-hol was used to extract the insulin in the cells and the amount of insulin synthesis of INS-1 cells was tested by RIA.5.6,1 6.7 mmol·L -1 glucose was used to chal-lenge INS-1 cells for 1 h to the insulin secretion model (BIS and GSIS)was tested,and the insulin secretion of INS-1 cells was tested via RIA.The mRNA expres-sion of insulin gene,PDX-1 and MafA was tested by q-PCR.Results Compared with medium group,GA could promote the proliferation of INS-1 cells signifi-cantly (P <0.01 )and promote the synthesis of insulin in INS-1 cells significantly (P <0.01 ).GA(0.3 ~30 nmol· L -1 )could promote the BIS,GSIS of INS-1 cells significantly (P <0.05 or P <0.01 ).GA (3,30 nmol·L -1 )could up-regulate the mRNA expression of insulin gene,PDX-1 ,MafA in INS-1 cells signifi-cantly (P <0.01 ).Conclusions GA could signifi-cantly improve the proliferation of INS-1 cells and pro-mote the insulin synthesis and secretion of INS-1 cells, which may be associated with up-regulation of insulin gene,PDX-1 ,MafA mRNA expression.