Primary Liver Cell Carcinoma 24 Years after Intravenous Injection of Thorotrast

Thorium dioxide, when injected intravenously, is taken up by the reticulo-endothelial system and retained indefinitely, rendering the liver and spleen radio-opaque A 25% col- loidal solution of thorium dioxide was mar- keted under the name of "thorotrast" and used not only for hepatolienography but for retrograde pyelography, bronchography, and angiography generally, not to mention other uses, e.g., cerebral 'ventriculography,