Radiation Dose Reduction in Different Digital Radiography Systems: Impact on Assessment of Defined Bony Structures in Bearded Dragons (Pogona vitticeps)

SIMPLE SUMMARY: Digital radiography has long been established in veterinary clinics, leading to increased use of digital systems in reptile species as well. In this study, we used different digital radiography systems on cadavers of bearded dragons (Pogona vitticeps). We aimed to examine the impact of a radiation dose reduction on the image quality and the assessment of defined skeletal structures. We employed a blinded assessment and a defined scoring system to evaluate the techniques tested. Our results demonstrate that both a 50% and a 75% reduction in the radiation dose significantly decreased image assessments. These findings highlight the need for correct radiation dose protocols to produce high-quality radiographs in reptile species. ABSTRACT: Three different digital detector systems were used to study the effect of a defined radiation dose reduction on the image quality of digital radiographs in bearded dragons (Pogona vitticeps). A series of radiographs of seven bearded-dragon cadavers with a body mass ranging from 132 g to 499 g were taken in dorsoventral projection. The digital systems employed included two computed radiography systems (CR) (one system with a needle-based and one with a powdered-based scintillator) and one direct radiography system (DR). Three levels of the detector dose were selected: A standard dose (defined based on the recommended exposure value of the CR(P), D/100%), a half dose (D/50%), and a quarter dose (D/25%). Four image criteria and one overall assessment were defined for each of four anatomic skeletal regions (femur, rib, vertebra, and phalanx) and evaluated blinded by four veterinarians using a predefined scoring system. The results were assessed for differences between reviewers (interobserver variability), radiography systems, and dosage settings (intersystem variability). The comparison of the ratings was based on visual grading characteristic (VGC) analysis. Dose reduction led to significantly lower scores in all criteria by every reviewer, indicating a linear impairment of image quality in different skeletal structures in bearded dragons. Scores did not differ significantly between the different systems used, indicating no advantage in using a computed or direct radiography system to evaluate skeletal structures in bearded dragons. The correlation was significant (p ≤ 0.05) for interobserver variability in 100% of the cases, with correlation coefficients between 0.50 and 0.59. While demonstrating the efficacy of the use of digital radiography in bearded dragons and the similar quality in using different computed or direct radiography systems, this study also highlights the importance of the appropriate level of detector dose and demonstrates the limits of post-processing algorithm to compensate for insufficient radiation doses in bearded dragons.