An Unusual Cause of γ-Camera Contamination

This report is of an unusual case of radioactive contamination of a γ-camera after scanning 2 individuals who had been treated 3 d beforehand with ablative doses of ¹³¹I for thyroid cancer. A combination of observed half-life and pulse-height spectroscopy was used to identify the contaminant. The source of the contamination was eventually found to be a single human hair, presumably contaminated when the individual was sucking her hair while waiting for the scan to start. This case demonstrates that hair can be contaminated by saliva and potentially other bodily fluids in the postablation setting and that using physical measurements, in this case the observed half-life and pulse-height spectroscopy, can be useful in identifying the radioactive contaminant.