Experimental in vitro study to evaluate a flat-panel detector system

Abstract

To evaluate the contrast-detail performance of a flat-panel detector system, we performed a comparative study of this flat-panel system versus storage phosphor and conventional screen-film systems. Bone models made of human humeri were prepared with foreign bodies, fracture lines and drilled holes to create artificial fractures, osteolyses or metastases. Immersed in a water bath, hard copy images of these models were acquired with the same exposure dose (55 kV; 3.2 mAs) on the flat-panel detector, two state-of-the-art storage phosphor systems (PCR, ADC) and two conventional screen-film systems (Insight, T-Mat). Using a standardized protocol with a 4-point scale for a lesion, 220 different images were analyzed as to their appearance by 5 independent radiologists. The statistical significance of the differences between the used modalities and the observers was determined with a sign test. Especially the drilled holes showed differences between the modalities. The flat-panel detector showed significantly slightly better results locally than the two storage phosphor systems. The same applied to the Insight screen-film systems, but the intraindividual differences between the modalities were not clinically relevant. Under the conditions of the chosen experimental design, the flat-panel detector showed results comparable to the conventional screen-film and the state of the art storage phosphor radiographs. The use in skeletal radiography is possible.