[Radiographic visualization of pleural space under negative pleural pressure]

Although many imaging modalities have developed in the area of pulmonary medicine, information about the condition of pleural surface is limited. In this study, we carried out contrast pleurography under negative pleural pressure in dogs and humans to evaluate the condition of the pleural space including adhesion between the two pleural layers, incomplete fissure and features of the pleural surface. After insertion of a flower-type catheter into the pleural space under ultrasonic guidance, contrast material (60% Meglumine iotalamate, Conray 60, 0.5-1.0 ml/kg) was injected into the pleural space through the catheter. In dogs with intact pleura, contrast material distributed to the pulmonary surface, including interlobar spaces, rapidly. In dogs with pleural adhesion which was induced artificially with talc, affected areas were visualized as defects of contrast material. In humans, this contrast pleurography provided information about pleural adhesion, pulmonary lobulation, extent of cancer to neighbouring lobes, irregular pleural surface due to bullae formation and pleural indentation by cancerous lesion. There was no serious complication in dogs and human studies. This contrast pleurography is unique because it is possible to evaluate the pleural space physiologically under negative pressure condition. It may be concluded that this method of pleurography is useful for the clinical evaluation of the condition of the pleura in various lung diseases.