Exposure indicator degradation from CR plate processing delays

Abstract

Purpose: To determine the percentage of exposure indicator (EI) degradation that occurs during a delay between exposure and processing of the imaging receptor.

Methods: Twenty-six images of a hand phantom, stepwedge and resolution test tool were created using a computed radiography (CR) system (Agfa Impax 6.3.1 SU5 CR, Agfa-Gevaert NV, Mortsel, Belgium). To control variables, exposures were made using the same technique, resulting in an EI of 2.0. The radiographic equipment, Agfa algorithms and processor and display monitor were held constant, and all imaging plates (IPs) were exposed and processed initially to rule out EI variation. Consecutive experimental exposures were made and each IP labeled by number and the time processed. To control ambient conditions, the exposed IPs were secured at room temperature in a radiation-free area until they were processed.

Results: The EI degraded 8% within the first hour of delay in processing. After 24 hours, degradation was 16%, demonstrating that the EI initially drops quickly following exposure, but degrades at a slower pace as the processing delay increases.

Conclusion: This study supports current literature by showing that more than half of the degradation that occurs in the first 24 hours happens within the first hour of delay in processing.