Niobium powder - a new contrast medium for tracheobronchography

In inhalation tracheobronchography with niobium powder in rabbits and a voluntary physician, excellent contour bronchograms with detailed imaging of the mucosa structure were obtained. With methodically proper application the niobium particles of 20-40 μm do not penetrate into the alveoles and are quickly (within 1-5 days) eliminated from the bronchi. Investigations with mice have shown, that niobium powder is insoluble, does not irritate tissues, and is not resorbed, and is therefore suggested to be non-toxic. (author)