Free Technetium: Potential Pitfall in the Diagnosis of Renovascular Hypertension

A 22-year-old woman had renography, including baseline and angiotensin-converting enzyme (ACE) inhibitor-assisted studies, in an evaluation for renovascular hypertension (RVH). Baseline renal scintigraphy performed with Tc-99m mercaptoacetyltriglicine (MAG3) was interpreted as normal. The study performed after ACE inhibitor administration showed abnormal time-activity curves suggesting the possibility of RVH. However, abnormal uptake in the left upper quadrant of the abdomen raised the possibility of inadvertent administration of free Tc-99m. A definitive diagnosis could not be made. An ACE inhibitor-assisted scan repeated 6 days later was normal.