Congress:
EuroSafe Imaging 2021
Keywords:
Radioprotection / Radiation dose, Digital radiography, Equipment, Quality assurance
Authors:
P. Sänger, C. Lappe, M.-A. Weber, M. Lütgens
DOI:
10.26044/esi2021/ESI-10702
Methods or background
In 2017 the last phosphor storage plate systems (AGFA CR MD 4.0) were replaced by digital detectors (Fuji FDR D-EVO II) in our university medical center. Both phosphor storage plates and detectors are image-receiving systems that deliver digital images and are characterized by a particularly wide dynamic range. In addition, the detectors with indirect conversion have a very high quantum efficiency of 60-70% compared to the previously used phosphor storage plates (20-35%). In order to compare the influence of the detector system changeover on the patient doses, we analyzed examinations before (2013-2014) and after the changeover (2017-2019). The main focus was placed on the analysis of the dose reduction in pediatric X-rays at a Fuji FXR MultiSuite radiography workstation.
In order to objectively evaluate the image quality at reduced doses, constancy test specimen images were obtained. In routine clinical practice, these images are acquired under the following conditions: an exposure time product of 40 mAs and an X-ray tube accelerating voltage of 70 kV. The constancy test images were now obtained using the digital detector instead of the phosphor storage plate. While the voltage was kept constant, the exposure time product was successively reduced. Starting at an exposure time product of 40 mAs, this was lowered to 20, 10, and 4 mAS.