Lanthanide-induced calcergy.

The subcutaneous injection of solutions of chloride salts of the rare earths is followed by calcification of the dorsal fascia in the mouse. The concentration of salt required to produce a constant, predictable response varies from salt to salt. The macroscopic outline of the reaction is generally irregular and therefore a quantitative radiological method has been developed to allow an accurate assessment of the dose/response relationship. This with the majority of salts is best described as a log regression and with three as a linear regression.