Steiner Natalie, Ludewig Eberhard, Tebrün Wiebke, Pees Michael
Department of Small Mammal, Reptile and Avian Diseases, University of Veterinary Medicine, 30559 Hanover, Germany.
Division of Diagnostic Imaging, Department of Small Animals and Horses, University of Veterinary Medicine, 1210 Vienna, Austria.
Animals (Basel). 2023 May 11;13(10):1613. doi: 10.3390/ani13101613.
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 (). 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, 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 ( ≤ 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.
使用三种不同的数字探测器系统，研究了特定辐射剂量降低对鬃狮蜥数字X线片图像质量的影响。对七只体重在132克至499克之间的鬃狮蜥尸体进行了一系列背腹位投影的X线片拍摄。所使用的数字系统包括两个计算机X线摄影系统（CR）（一个基于针状闪烁体，一个基于粉末状闪烁体）和一个直接X线摄影系统（DR）。选择了三个探测器剂量水平：标准剂量（根据CR的推荐曝光值定义，D/100%）、半剂量（D/50%）和四分之一剂量（D/25%）。针对四个解剖骨骼区域（股骨、肋骨、椎骨和指骨）中的每一个定义了四个图像标准和一个总体评估，并由四名兽医使用预定义的评分系统进行盲法评估。评估结果以确定审阅者之间（观察者间变异性）、X线摄影系统和剂量设置（系统间变异性）之间的差异。评级比较基于视觉分级特征（VGC）分析。剂量降低导致每位审阅者在所有标准下的得分显著降低，表明鬃狮蜥不同骨骼结构的图像质量呈线性受损。所使用的不同系统之间得分无显著差异，表明在使用计算机或直接X线摄影系统评估鬃狮蜥骨骼结构方面没有优势。观察者间变异性在100%的病例中具有显著相关性（≤0.05），相关系数在0.50至0.59之间。该研究在证明数字X线摄影在鬃狮蜥中的应用效果以及使用不同计算机或直接X线摄影系统时的相似质量的同时，也强调了适当探测器剂量水平的重要性，并证明了后处理算法在补偿鬃狮蜥辐射剂量不足方面的局限性。
