What happens if you delay scanning Digora phosphor storage plates (PSPs) for up to 4 hours?

OBJECTIVES: To assess, both objectively and subjectively, the effects of different combinations of storage conditions and delaying scanning for up to 4 h on digital images captured using Digora phosphor storage plates (PSPs). METHOD: Standardized images were obtained of an aluminium step wedge and dry mandible in acrylic using GE 1000 and phosphor storage plates (PSPs) from the Digora (Soredex) digital system. 12 plates were exposed and immediately scanned to produce the baseline gold standard. The plates were re-exposed and stored using three different storage combinations--(A) ambient temperature, (R) refrigeration and (S) low humidity, and then scanned after 10 min, 30 min, 1 h, 2 h, 3 h or 4 h. The objective analysis was carried out by pixel density measurements and the data analysed statistically using analysis of variance. Subjective analysis was carried out by three oral radiologists and the results analysed using the Mann Whitney U-test. RESULTS: Objective analysis showed loss of pixel density after 4 h using all storage combinations. Subjectively, this loss of density was not evident. CONCLUSION: There is a loss of image density at 4 h when using Digora PSPs which can not be detected clinically, but could compromise multisite research.