[Estimation of 99mTc-dimercaptosuccinic acid renal uptake using single photon emission computed tomography]

Renal function was assessed by measurement of 99mTc-dimercaptosuccinic acid (DMSA) uptake by the kidney based on the transsectional tomographic image obtained by single photon emission computed tomography (SPECT). The renal uptake was expressed as percentage of the total radioactivity detected in the kidney, the volume of which was measured by convolution method, against the amount dosed. Absorption was corrected by GE-STAR method using cut off level of 42%. In order to determine normal range, measurement was made for 40 kidneys of each of 10 male and female volunteers confirmed of having normal kidneys both morphologically and functionally. The average volume of the kidney was 220.4 ml for the right and 239.3 ml for the left for males, and 205.9 ml and 236.5 ml, respectively for females. The renal uptake of radioactivity (at 2 h after injection), was 26.8% for the right and 27.6% for the left for males, with corresponding figures for females being 26.4% and 27.9%, respectively. Distribution range of renal volume and renal uptake was obtained by bivariate analysis with 90% and 95% probability. From these results, our method of renal function determination based on renal uptake of 99mTc-DMSA obtained from renal transactional tomogram by SPECT is considered to be accurate and potentially useful for clinical purpose.