99mTc-MAG3 renography: normal values for MAG3 clearance and curve parameters, excretory parameters, and residual urine volume.
OBJECTIVE
Specific quantitative measurements have been recommended to assist in the interpretation of technetium-99m mercaptoacetyltriglycine (MAG3) renal studies. Our objective was to define the sex- and age-specific normal ranges for these recommended parameters.


METHODS
Data were obtained from a retrospective analysis of 106 subjects who were evaluated for kidney donation. The MAG3 clearance was calculated using a common camera-based method. The relative uptake, prevoid/postvoid and postvoid/maximum count ratios were determined using whole-kidney regions of interest (ROIs). Time to peak, time to half-peak, 20 min/maximum and 20 min/2-3 min count ratios were determined for cortical and whole-kidney ROIs. Residual urine volume was calculated on the basis of the pre- and postvoid bladder counts and voided urine volume.


RESULTS
The mean camera-based MAG3 clearance was 321 +/- 69 mL/min/1.73 m2, essentially the same as the mean plasma sample MAG3 clearance in comparable populations. The percentages of relative uptake in the right and left kidneys were 49% and 51% +/- 4%, respectively; no difference was seen between men and women. Cortical values were lower than the whole-kidney values (p < 0.001); the mean cortical 20 min/maximum count ratio was 0.19 (SD, 0.07 and 0.04 for right and left kidneys, respectively). The mean postvoid/maximum whole-kidney count ratio was < 0.1, and the mean postvoid residual bladder volume was < 30 mL.


CONCLUSIONS
Normal limits adjusted for age and sex have been established. Applying normal ranges to quantitative MAG3 parameters may assist in the interpretation of MAG3 scintigraphy and facilitate appropriate patient management.
Esteves
Fabio P
FP
Department of Radiology, Division of Nuclear Medicine, Emory University Hospital, 1364 Clifton Rd. NE, Atlanta, GA 30322, USA.
Taylor
Andrew
A
Manatunga
Amita
A
Folks
Russell D
RD
Krishnan
Meghna
M
Garcia
Ernest V
EV
D000328:Adult; D000367:Age Factors; D005260:Female; D006801:Humans; D007668:Kidney / Q000737:chemistry / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011866:Radioisotope Renography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D012016:Reference Values; D012189:Retrospective Studies; D012737:Sex Factors; D017263:Technetium Tc 99m Mertiatide / Q000493:pharmacokinetics*; D014563:Urodynamics
D019275:Radiopharmaceuticals; D017263:Technetium Tc 99m Mertiatide