Determination of single-kidney glomerular filtration rate (GFR) with CT urography versus renal dynamic imaging Gates method
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To present a single-kidney CT-GFR measurement and compare it with the renal dynamic imaging Gates-GFR.
Materials and methods
Thirty-six patients with hydronephrosis referred for CT urography and 99mTc-DTPA renal dynamic imaging were prospectively included. Informed consent was obtained from all patients. The CT urography protocol included non-contrast, nephrographic, and excretory phase imaging. The total CT-GFR was calculated by dividing the CT number increments of the total urinary system between the nephrographic and excretory phase by the products of iodine concentration in the aorta and the elapsed time, then multiplied by (1- Haematocrit). The total CT-GFR was then split into single-kidney CT-GFR by a left and right kidney proportionality factor. The results were compared with single-kidney Gates-GFR by using paired t-test, correlation analysis, and Bland-Altman plots.
Paired difference between single-kidney CT-GFR (45.02 ± 13.91) and single-kidney Gates-GFR (51.21 ± 14.76) was 6.19 ± 5.63 ml/min, p<0.001, demonstrating 12.1% systematic underestimation with ±11.03 ml/min (±21.5%) measurement deviation. A good correlation was revealed between both measurements (r=0.87, p<0.001).
The proposed single-kidney CT-GFR correlates and agrees well with the reference standard despite a systematic underestimation, therefore it could be a one-stop-shop for evaluating urinary tract morphology and split renal function.
• A new CT method can assess split renal function
• Only using images from CT urography and the value of haematocrit
• A one-stop-shop CT technique without additional radiation dose
KeywordsComputed tomography (CT) CT urography Glomerular filtration rate (GFR) Split renal function One-stop-shop technique
glomerular filtration rate
99mTc diethylenetriamine pentaacetic acid
CT number increments of the urinary system between the nephrographic and excretory phases.
Products of iodine concentration in the aorta and the time interval between the nephrographic and excretory phases.
This study has received funding by National Natural Science Foundation of China (NO. 81671680)
Compliance with ethical standards
The scientific guarantor of this publication is Yuan XiaoDong.
Conflict of interest
The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article.
Statistics and biometry
One of the authors (Yuan XiaoDong) has significant statistical expertise.
Institutional Review Board approval was obtained.
Written informed consent was obtained from all subjects (patients) in this study.
• performed at one institution
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