Quantitative SPET 99Tcm-DMSA uptake by the kidneys: age-related decline in healthy males

To evaluate if 99Tcm-dimercaptosuccinic acid (99Tcm-DMSA) uptake by the kidneys is related to age and creatinine clearance in males with normal renal function, quantitative single photon emission tomography (SPET) of DMSA uptake by the kidneys was performed in 18 volunteers aged 20-79 years. The quantitative uptake of DMSA in the right kidney was 13.9 +/- 2.9% and in the left kidney 14.2 +/- 3.0%. There was no statistically significant difference between left and right kidney uptake (t = 1.2, N.S.). Global kidney uptake (right + left) was 28.1 +/- 5.9%. There was a statistically significant age-related decline in global DMSA uptake. The estimated DMSA uptake (%) was given by -0.27 x age + 42 (r = -0.87, P < 0.001). A good correlation was found between creatinine clearance and global DMSA uptake (r = 0.87, y = 2.8x + 28.3, P < 0.001). The results suggest that normal values of DMSA uptake by the kidneys are age-dependent.