Comparison of Tc-99m pyrosphosphate and Tc-99m hydroxymethylene diphosphonate in acute myocardial infarction: concise communication.

A clinical comparison between a new bone seeking radiopharmaceutical, Tc-99m hydroxymethylene diphosphonate (TcHMDP) and the standard agent, Tc-99m pyrophosphate (TcPPi), was performed in 18 patients with acute myocardial infarction. Each patient was imaged initially with either TcHMDP or TcPPi, and imaged 24 hr later with the other tracer. All 18 patients had images positive for acute myocardial infarction with TcPPi, whereas 16 of 18 patients (89%) had positive studies with TcHMDP.

Plasmacytoma simulating meningioma on brain scan.

The flow study and static images of the brain scans of two patients with plasmacytoma of the skull were identical to the pattern most commonly seen with meningioma. There was a prominent blush on dynamic imaging which did not wash out combined with an intense uptake on static views adjacent to a meningeal surface. In patients with known multiple myeloma, the diagnosis of plasmacytoma of the skull or cranial cavity should be considered when this characteristic pattern is seen.