Identification of thorotrast by gamma-spectrometry and simplified autoradiography in pathological specimens

Simplified and reliable methods for identifying thorotrast are demonstrated. On gamma-ray spectrometry, as little as 0.1 g of liver tissue gives gamma-ray spectrum characteristics to the thorium decay series, despite a low net count. When conventional film for photography is kept in contact with a paraffin section of the liver for 4 months, it develops silver grains exactly corresponding to the area of granular deposition. By combining this method with clinical and pathological findings, a diagnosis of thorotrastosis can be established without the need for special instruments or materials.