Comparison of camera-based 99mTc-MAG3 and 24-hour creatinine clearances for evaluation of kidney function.
OBJECTIVE
The 24-hour creatinine clearance is the standard clinical technique for measuring kidney function; however, this measurement is cumbersome and inconvenient for patients. We hypothesized that a camera-based technetium-99m mercaptoacetyltriglycine (MAG3) clearance obtained simultaneously with a standard MAG3 scan would correlate well with the 24-hour creatinine clearance and could serve as a simple marker of kidney function.


METHODS
Data were obtained from a retrospective analysis of 28 patients with varying degrees of kidney dysfunction and 85 subjects evaluated for kidney donation. The MAG3 clearance was calculated using a camera-based technique without blood or urine sampling. The creatinine clearance was measured using the plasma creatinine and a 24-hour urine collection. The MAG3 and creatinine clearances were corrected for body surface area, and clearance values in healthy subjects and patients were compared using the paired Student's t test. The linear association between the MAG3 and creatinine clearances was expressed by Pearson's correlation coefficient.


RESULTS
The mean MAG3 clearance in the potential kidney donors was 321 +/- 95 mL/min/1.73 m2 (95% CI, 171-546 mL/min/1.73 m2), significantly higher than the mean creatinine clearance of 152 +/- 51 mL/min/1.73 m2 (79-278 mL/min/1.73 m2, p < 0.001). The mean MAG3 clearance in patients was 153 +/- 70 mL/min/1.73 m2 (32-316 mL/min/1.73 m2) and was also significantly higher than the mean creatinine clearance of 74 +/- 36 mL/min/1.73 m2 (21-138 mL/min/1.73 m2, p < 0.001). The ratio of the mean creatinine clearance to the mean MAG3 clearance was essentially the same for volunteers and patients, 0.47 and 0.48, respectively. The Pearson's correlation between the MAG3 and creatinine clearances was 0.80 (0.72-0.86).


CONCLUSIONS
The camera-based 99mTc-MAG3 clearance correlates well with the 24-hour creatinine clearance and can provide a simple and convenient index of kidney function.
Esteves
Fabio P
FP
Department of Radiology, Division of Nuclear Medicine, Emory University School of Medicine, 1364 Clifton Rd. NE, Atlanta, GA 30322, USA.
Halkar
Raghuveer K
RK
Issa
Muta M
MM
Grant
Sandra
S
Taylor
Andrew
A
D000328:Adult; D003404:Creatinine / Q000378:metabolism*; D005260:Female; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging* / Q000502:physiology*; D007674:Kidney Diseases / Q000000981:diagnostic imaging; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D017263:Technetium Tc 99m Mertiatide; D014019:Tissue Donors
D019275:Radiopharmaceuticals; D017263:Technetium Tc 99m Mertiatide; D003404:Creatinine