correlations and differences in glomerular filtration rates calculated through in-house and non-in-house workstations of scintigraphic gamma cameras

Background: technetium-99m diethylene triaminepentaacetic acid (tc-99m dtpa) renal scintigraphy using modified gate’s method is commonly adopted to calculate glomerular filtration rate (gfr). objectives: the purpose of this study was to find the correlations between gfrs, which are calculated by the in-house and non-inhouse workstations from gamma cameras (gc) manufactured by different firms. patients and methods: medical records of patients receiving tc-99m dtpa renal scan between january and december 2016 were analyzed. patients were allocated randomly to a gc (1 or 2). the calculated gfrs were conducted by the in-house workstation (group a: workstation 1/ gc 1; group b: workstation2/ gc 2) and the non-in-house workstation from the gc (group c: workstation 2/ gc 1; group d: workstation 1/ gc 2). all patients had their creatinine levels checked to calculate the estimated grf (egfr) as the reference data. comparison of correlation and difference between gfr calculations (group a, b, c and d), egfrs and clinical parameters was analyzed. results: forty patients (24 men, 16 women) were enrolled in this study. the average of egfrs was 63.0  38.5 ml/min/1.73m2. the gfrs (group a to d) calculated were all significantly correlated with the egfr. however, there was a significant difference between group c and egfr (p = 0.0021), and group d and egfr (p = 0.0262). eight patients (20%) had changed stage of chronic kidney disease when using non-in-house workstations, compared to in-house workstations from gc. conclusion: gfrs calculated by the non-in-house workstation were significantly different from egfr. use of workstation and gc from the same manufacturer would provide more accurate data in the clinical setting.