Comparison of computerized digital and analog radiography for detection of bronchial pattern in dogs

Background: Analog radiography has been replaced with digital radiography for canine diagnostic imaging in many veterinary clinics. There is no data comparing these modalities in a veterinary clinical setting to detect bronchial pattern signs in dogs. Objectives: In this study, computerized digital radiography (CR) and analog radiography were compared for diagnosis of bronchial pattern in dogs. Methods: Forty-five healthy (based on clinical examination and history taking) mixed breed dogs were divided into 3 age groups: up to two, two-six and more than 6 years old. Each group contained fifteen dogs. DR and FSR in right to left lateral (RL) and ventrodorsal (VD) views were taken. Two expert radiologists interpreted the radiographs based on counting bronchial ring and tram line signs in a double blinded scheme. Results: The statistical analysis of results, with Sign Test, shows that more bronchial ring and tram-like signs were counted with both radiologists using digital radiography. In addition, countable bronchial signs on right lateral position by digital and analog radiography were significantly more than in ventrodorsal view. In comparison with analog images, a greater number of bronchial ring and tram-like signs are associated with greater diagnostic confidence in digital modality. Conclusions: This study shows superior ability of digital radiography for detecting details in thoracic radiography of normal dogs in comparison with analog radiography. Since digital radiography is getting to be more commonly used by veterinary practitioners, it is necessary to understand the shortcomings of current classification of pulmonary pattern approach in digital radiology.