The usefulness of Tc-99m DMSA SPECT and three-dimensional surface rendering in an asymptomatic patient with a single kidney in the pelvis.

The diagnostic problems in a clinically asymptomatic patient with a previously unknown ectopic single kidney in the pelvis and the diagnostic utility of three-dimensional surface rendering of Tc-99m DMSA SPECT for delineating ectopic functional renal parenchyma are reported. Inconclusive dynamic planar Tc-99m MAG3 renal scintigraphy was performed with the field of view centered at the upper abdomen. Twenty-four hours later, static planar Tc-99m DMSA scintigraphy 3 hours after injection delineated functional renal parenchyma only in the pelvis but did not reveal the shape of the organ. Three-dimensional surface rendering exposed a single ectopic kidney in the pelvis. This case is the first description of the advantages of three-dimensional surface rendering of Tc-99m SPECT in the diagnosis of an ectopic kidney.