RT Journal Article SR Electronic T1 Artifact from 131I contaminated mask in post-radioiodine therapy scintigraphy JF Journal of Nuclear Medicine Technology JO J. Nucl. Med. Technol. FD Society of Nuclear Medicine SP jnmt.121.262438 DO 10.2967/jnmt.121.262438 A1 Betti, Francesca A1 Antonacci, Luca A1 Volterrani, Duccio YR 2021 UL http://tech.snmjournals.org/content/early/2021/07/30/jnmt.121.262438.abstract AB An occurrence of an artifact due to contamination is reported. A patient wearing the mandatory face mask because of the ongoing COVID-19 pandemic underwent post-radioiodine therapy scintigraphy. The spot view of the neck showed an area of intense iodine uptake with an unusual appearance. Suspecting a possible artifact due to iodine contamination, the patient was given a new mask to wear and the scan was repeated. Results. The subsequent images revealed that the previously detected hotspot was caused by mask contamination. Conclusions. This finding has led to updating the scan procedure for post-therapy scintigraphy by replacing the patients’ masks before the scan acquisition.