Radiology of Digital Technology applied to painting: Assessment of Images’ quality obtained through clinical x-Ray systems

Abstract

Introduction: The area’s studies have a great relevance in artwork. Laboratories committed to this purpose are scarce and employ professionals without specific knowledge in handling of ionizing radiation. It is not known to what extent, in Portugal, clinical radiological centers could provide added value to technology of digital radiography applied to painting, in order to expand their business areas and the performance of radiographers, thus enhancing synergies between these two areas. Goals: It was intended to analyse a possible applicability, to painting, of the Digital Radiology systems (CR and DR), used in the clinic settings, through the evaluation of the variable “radiographic image quality”, since the systems Clinical radiological tests, with indirect or direct conversion detectors of different energies and photodetectors of the electrical signal, show significant improvements in imaging patterns. Material and Methods: 21 radiographs were obtained from exposures made over three paintings in three different radiological systems with an emphasis on exposure parameters (potential difference (kV) and current intensity (mAs)). The sample was directed to works that presented different techniques, materials and compositions and selected by a museologist. The quality of the radiographs, operationalized by the analysis’s dimensions used in the evaluation of artworks: preservation of the support; distinction of details; contrast; contour definition; creative and technical process and components / materials. Four observers (2 specialists in medical image and 2 in art), under conditions of independence, evaluated the radiographs acquired according to a 4-point Likert scale. The analysis dimensions were organized into 11 criteria and the conditions for structured observation of the radiographs were standardized for display on a 15.6 ”GeChic 1503H monitor. Results: The most graded images were obtained with the Computerized Radiography (CR) system (mode: 3) given that this technology, in the opinion of the observers, provided a better view of the analysis criteria previously defined. The results were presented using descriptive statistics and discrete categorical variables, grouped into modal classes. Conclusions: Clinical digital radiography, especially Computed Radiography (CR), applied to painting, showed considerable dimensions of image quality and its use can contribute to the conservation, restoration, validation, analytical study, dating and authentication of artworks.