The Effects Of Radiopharmaceuticals On GFR Were Measured At Different Distances Before And After SPECT Renal Dynamic Imaging

Objective:To investigate the influence of radiopharmaceuticals measured at different distances on glomerular filtration rate（GFR）in SPECT renal dynamic imaging,in order to find a more suitable method for distance measurement of radiopharmaceuticals.Methods:SPECT renal dynamic imaging was performed on 40patients to determine GFR.Before and after SPECT imaging,radiopharmaceuticals were collected when the probe was 5cm,20cm,and30cm away from the moving bed（blocked by the moving bed）before and after the SPECT imaging（the syringe with the medicine before the renal dynamic imaging and the syringe after the injection after the renal dynamic imaging）Count and record the radioactivity counts of the 3 methods.Three groups of GFR were obtained by delineating the ROI according to the visually distinguishable area by the Gates method,and compared the GFR of the three methods with the double plasma method GFR（d GFR）.Results:The paired t-test between the 5cm,20cm,and 30cm groups respectively and the double plasma method group showed that the GFR measured by the 5cm group and the double plasma method group were significantly different（P<0.05）,and the 20cm,30cm group and the double plasma method group There is no significant difference（all p>0.05）;the Pearson correlation analysis results of the 5cm,20cm,and 30cm groups respectively and the double plasma method group indicate that the three methods are significantly correlated with the GFR measured in the double plasma group,but 30cm The correlation was highest in the group（r₁=0.809,r₂=0.823,r₃=0.838）;the GFR values of the 5cm,20cm,and 30cm groups were compared with the double plasma method group.The Bland Altman consistency analysis was（-4.2±12.6m L/min,-1.6±13.5m L/min,1.4±11m L/min）.In summary,it can be concluded that the three different distance measurement radiopharmaceuticals measured by SPECT renal dynamic imaging have a strong correlation with the GFR measured by the double plasma method group.The paired t-test between the radiopharmaceutical group measured at 5cm and the double plasma method is quite different.There is no significant difference between the radiopharmaceutical group measured at 20cm and 30cm and the paired t-test with double plasma method.The radiopharmaceutical group measured at 30cm has the highest correlation and consistency with the double plasma method.it is good.The difference between the GFR measured by the 5cm radiopharmaceutical group and the double plasma method group was the largest.The 30cm measurement radiopharmaceutical group is closer to the GFR measured in the double plasma group.Conclusion:SPECT renal dynamic imaging requires a certain distance to collect radiopharmaceutical counts.Measuring radioactivity counts at different distances will affect the results of renal dynamic imaging GFR.The best distance for measuring radiopharmaceuticals is 30cm,and it is not appropriate to choose a closer distance.