[Measurement of glomerular filtration rate with renal dynamic imaging: comparison with two-sample method].
OBJECTIVE
To compare the estimation of glomerular filtration rate (GFR) by renal dynamic imaging with that estimated by two-sample method and evaluate the reliability of measurement of GFR by renal dynamic imaging.


METHODS
The study was performed in 54 patients (33 males and 21 females; aged 15 to 82 years) with primary or secondary chronic nephrosis. The patients were intravenously bolus injected with 185 MBq /1mL of (99)Tc(m)-DTPA 20 min after drinking 300 mL of water. Renal dynamic imaging was performed and the image was processed according to standard procedure (Gates' method) to obtain GFR. 3 mL of blood was withdrawn 2 h and 4 h postinjection, respectively, and radioactivity of 1mL plasma was measured. GFR was calculated by the formula of two-sample method. The correlation of GFRs measured by renal dynamic imaging and by two-sample method was analyzed using regression analysis. The correlations of GFRs determined by the two methods with urea and creatinine were also measured.


RESULTS
The GFR measured by renal dynamic imaging was slightly lower than that measured by two-sample method. Excellent correlation was obtained by two methods with r= 0.881 5 and P<0.01. The linear regression equation was GFR (renal dynamic imaging method)=0.661 4GFR (two-sample method) +21.89. The related lines of GFRs measured by the two methods with urea or creatinine were similar, which indicated the two methods were similar in identifying the changes in renal function. GFRs measured by the two methods showed good agreement for most of patients except three patients who were too thin or too fat.


CONCLUSIONS
Generally, GFR obtained by renal dynamic imaging is reliable for identifying the changes in renal function and correlated well with GFR obtained by two-sample method. But great error may be obtained with specific individuals, such as too thin or too fat subjects.
Zhang
Chun-li
CL
Deptartment of Nuclear Medicine, Peking University First Hospital, Beijing 100034, China. ups1000@sina.com
Li
Qian
Q
Zuo
Li
L
Cui
Ying
Y
Wang
Yan-fu
YF
Guo
Feng-qin
FQ
Zhao
Guang-yu
GY
Zhang
Xu-chu
XC
Zhou
Yu-hong
YH
Wang
Rong-fu
RF
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D009401:Nephrosis / Q000175:diagnosis / Q000503:physiopathology*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016284:Technetium Tc 99m Pentetate; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D019275:Radiopharmaceuticals; D003404:Creatinine; D016284:Technetium Tc 99m Pentetate