[Clinical evaluation of asymmetric film-screen system for thoracic lesions]

We investigated the clinical usefulness of the asymmetric film-screen system on postero-anterior chest roentgenograms for thoracic lesions. The asymmetric film-screen system, the so-called Kodak Insight thoracic imaging system, records a different image on each side of double-emulsion film. An image displaying the lung field is captured on the anterior side of the film, while one displaying the mediastinal, retrocardiac and retrodiaphragmatic structures is captured on the posterior side. The clinical usefulness of the asymmetric film was evaluated in 20 patients for visibility of the anatomical structures and abnormal lesions in comparison with conventional film. In the asymmetric film-screen system, the front and rear screens were HC (high contrast) and Regular, respectively. Chest radiography was performed at 200mA and 100kVp. As conventional film, we used SRC film (Konica, orthotype film), and chest radiography was performed at 100mA and 130kVp. The chest roentgenograms obtained with the asymmetric film-screen system provided better information on normal structures and abnormal lesions in the lung field, but slightly inferior information on mediastinal structures. In conclusion, it was considered that the asymmetric film-screen system was useful for thoracic lesions.