Solitary defect on liver sulfur colloid imaging secondary to focal fatty infiltration

Radionuclide liver-spleen imaging using Tc-99m SC may identify focal defects on routine examinations. Fatty infiltration has generally been described as a diffuse process in the liver that may be manifested on Tc-99m SC liver imaging as a nonhomogeneous pattern of radiopharmaceutical distribution or multiple small defects. This case demonstrates a focal defect on radionuclide imaging, simulating a space-occupying lesion that ultimately proved to be focal fatty infiltration. Although not an uncommon finding on CT, to the authors' knowledge this has not been reported in the nuclear medicine literature to date.