Renal function study by sup(99m)Tc-DMSA renal scintigraphy in non-obstructive upper urinary tract infection

Kidney function study was carried out in 90 patients with non-obstructive upper urinary tract infection using sup(99m)Tc-DMSA (dimercaptosuccinic acid) renal scintigraphy. sup(99m)Tc-DMSA renal scintigram demonstrated well pyelonephritic cortical lesions which were not easily visualized on IVP. A variety of sup(99m)Tc-DMSA renal uptake paralleled the grading of pyelonephritic changes in IVP, however, there was a discrepancy between some of grade II pyelonephritic changes in reflux kidneys and DMSA renal uptake. This may be partly attributed to hydrodynamic effects of VUR in addition to inflammatory changes. The severity of reflux and changes in pelviocaliceal system on VCG also paralleled DMSA renal uptake in reflux kidneys. A ratio of sup(99m)Tc-DMSA renal uptake in the healthy side to that in pathological side was observed in 23 cases with VUR before and after the anti-VUR operation was performed. In patients with more than 3.5 of preoperative DMSA uptake ratio, there were few increments postoperatively in kidney functions of the pathological side, while the contralateral healthy kidney showed a compensatory increase in kidney function. This DMSA renal uptake ratio between healthy and pathological side seems to be one of predictable determinants for postoperative recovery of the pathological side. Thus, by comparing the DMSA uptake between right and left kidney in the chronic course or pre- and postoperative periods, an effect of renal function in the pathological side on that in the healthy side was investigated from the point of renal counterbalance. (author)