PT - JOURNAL ARTICLE AU - Joseph E. Glaser AU - Na Song AU - Sridivya Jaini AU - Ruth Lorenzo AU - Charito Love TI - Photomultiplier Tube Artifacts on <sup>67</sup>Ga-Citrate Imaging Caused by Loss of Correction Floods Due to an Off-Peak Status of One Head of a Dual-Head γ-Camera AID - 10.2967/jnmt.111.097246 DP - 2012 Dec 01 TA - Journal of Nuclear Medicine Technology PG - 278--280 VI - 40 IP - 4 4099 - http://tech.snmjournals.org/content/40/4/278.short 4100 - http://tech.snmjournals.org/content/40/4/278.full SO - J. Nucl. Med. Technol.2012 Dec 01; 40 AB - γ-cameras use flood-field corrections to ensure image uniformity during clinical imaging. A loss or corruption of the correction data of one head of a dual-head camera can result in an off-peak artifactual appearance. We present our experience with the occurrence of such an incident on a 67Ga scan. Methods: A patient was referred for a whole-body 67Ga scan to evaluate for causes of neutropenic fever. Whole-body planar and static images of the head, chest, abdomen, pelvis, and lower extremities in multiple projections were obtained. Results: Whole-body images showed decreased image quality on the anterior view obtained with detector 1 and an unremarkable posterior image obtained with detector 2. A problem with detector 2 was suspected, and additional static images were obtained after rotation of the detector heads. The posterior images taken with detector 1 showed photomultiplier tube outlines. The anterior images taken with detector 2 showed improved count and image quality. It was later found that the uniformity map for detector 2 had been lost and that this software malfunction led to the resulting imaging problem. Conclusion: When artifacts with an off-peak appearance are seen on scintigraphic images, evaluation of possible causes should include not only isotope window settings but also an incorrect or corrupted uniformity map.