Validity of Tc-99m-DMSA renal uptake by planar posterior-view method in children

Renal uptake of Tc-99m-DMSA has been quantified by various methods. The aim of this study is to obtain a normal value for Tc-99m-DMSA renal uptake cal culated by the posterior view method and age variation, and to assess its c linical validity. Scintigrams of 238 children (0-12 years) with Tc-99m-DMSA were reviewed. All the children had a clinical history of primary vesicour eteral reflux and/or neurogenic bladder, ureteral or urethral anomalies. Th eir kidneys were divided into two groups, "normal" and "abnormal" according to their scintigraphic findings and split renal functions. Percent renal u ptake per injected dose (% RU) was quantitated from planar images at 2 hour s after injection of an age-adjusted dose (26-95 MBq) of Tc-99m-DMSA. Calcu lated total % RU, individual % RU of the right and left kidneys (mean +/- s d) in patients with normal kidneys were 40.7 +/- 5.0%, 20.2 +/- 3.0%, 20.4 +/- 2.7%, respectively. There was no significant correlation between % RU a nd age (r = 0.231). Longitudinal variation in the % RU in 9 patients ranged from 1.2% to 18%. Our conventional method for quantifing % RU is simple, p ractical and feasible in routine clinical practice, especially for children under follow up.