不同能量放射性核素在PET/CT及SPECT采集中的相互影响

目的 利用模型探讨99TcmO4-与18F-氟脱氧葡萄糖(FDG)在图像采集中的相互影响,讨论同一患者是否可以同日分别采用PET/CT及SPECT两种仪器行高低两种能量放射性核素显像.材料与方法 利用统一规格、相同容积( 500ml)的5个塑料瓶(编号A、B、C、D、E),其内均注入500ml蒸馏水制作成模型.A瓶注入0.5mCi 18F-FDG行PET/CT显像;B瓶注入1mCi99TcmO4-行SPECT显像;C瓶内同时注入混合好的0.5mCi18F-FDG和1mCi99TcmO4-;D瓶内先注入1mCi99TcmO4-后再注入0.5mCi18F-FDG;E瓶先注入0.5mCi18F-FDG后再注入1mCi99TcmO4-.然后对C、D、E瓶分别行PET/CT显像和SPECT显像,并判断图像效果.结果 A瓶PET/CT显像和B瓶SPECT显像图像效果为1级;C、D瓶SPECT及PET/CT显像图像均为2级;E瓶SPECT显像图像为3级,PET/CT显像图像为1级.结论 同时加入18F-FDG和99TcmO4-对PET/CT和SPECT图像质量均有影响.先加入18F-FDG后加入99TcmO4-对PET/CT图像质量影响小,但SPECT图像不能分辨.先加入99TcmO4-后加入18F-FDG对PET/CT和SPECT图像质量均有影响.

Interaction Between PET/CT and SPECT in Different Energies of Radioisotopes

Purpose To evaluate interaction between 99 Tc m O 4-and 18 F-FDG in the image acquisition,and to discuss if the patient is eligible to perform radionuclide imaging with high-energy and low-energy by SPECT and PET/CT respectively on the same day.Materials and Methods The cardiac models were made by 5 plastic bottles with uniform specification and the same volume (500 ml).All the bottles were filled in 500 ml water and numbered A,B,C,D and E,respectively.18 F-FDG was added to bottle A and performed PET/CT.99 Tc m O 4-was added to bottle B and performed SPECT.Mixed 0.5mCi 18 F-FDG and 1mCi 99 Tc m O 4-was added to bottle C,and for bottle D,1mCi 99 Tc m O 4-was added first and followed by 0.5mCi 18 F-FDG.For bottle E,0.5mCi 18 F-FDG was added first and followed by 1mCi 99 Tc m O 4-.Then all of C,D,E bottles performed PET/CT and SPECT imaging respectively,and the grades of images were evaluated.Results PET/CT imaging quality were grade Ⅰ for bottle A and SPECT imaging quality were gradeⅠfor bottle B.Both of PET /CT and SPECT imaging quality were grade Ⅱ for bottle C and bottle D.SPECT imaging quality were grade Ⅲ,and PET /CT images quality were grade Ⅰ for bottle E.Conclusion If 99 Tc m O 4-and 18 F-FDG are adding at the same time,both image quality of PET/CT and SPECT will be reduced.If 18 F-FDG is adding first and followed by 99 Tc m O 4-,PET /CT image quality will be slightly reduced,but SPECT images cannot be distingushed.If 99 Tc m O 4-is adding first and followed by 18 F-FDG,both PET /CT and SPECT imaging quality will be reduced.