Efficacy of nonionic low-osmolar gadodiamide injection in animals with intracranial mass lesions.

Gadodiamide injection is a nonionic, low-osmolar formulation of a paramagnetic metal chelate complex consisting of gadodiamide and caldiamide sodium. The efficacy of gadodiamide injection as a magnetic resonance (MR) imaging enhancement medium was evaluated by imaging intracranial 9L-glioma lesions induced in rats and naturally occurring lesions in dogs. T1- and T2-weighted spin-echo images were obtained before and after administration of gadodiamide injection at doses of 0.1 and 0.2 mmol/kg. On the precontrast T1-weighted images, the intracranial lesions were not well seen, appearing isointense to normal brain parenchyma. Although the presence of disease was shown unequivocally on the T2-weighted images, the margins of the masses could not be delineated. Postcontrast T1-weighted images were characterized by marked enhancement of the tumor, with no change in signal intensity in the surrounding edematous brain tissue. Gadodiamide injection was efficacious in identifying areas of blood-brain barrier breakdown associated with intracranial masses.