RESUMEN
Experimental study of a new paramagnetic complex Mn-DCTA is carried out. The complex (0.5 M manganese(II) solution with trans-1,2-diamine cyclohexane-N,N,N',N'-tetraacetic acid; Cyclomang) was used for contrast magnetic resonance imaging visualization of CNS involvement in dogs with severe forms of Babesia canis infection. CNS injuries were visualized in all cases, with highly intense contrasting at the expense of Mn-DCTA accumulation at the periphery of the damaged zone. Quantitative evaluation of the paramagnetic accumulation in the focus showed that the amplification index wa s 1.19±0.11 for the central areas and 1.47±0.17 for the peripheral ones. The pituitary (1.18±0.05) and vascular plexuses of the lateral ventricles (1.12±0.09) were also contrasted. Injection of the paramagnetic to dogs was not associated with any kinds of pathological or physiological reactions. Mn-DCTA complex allowed contrast visualization of the focal injuries to the CNS and could be regarded as a paramagnetic contrast agent for magnetic resonance imaging of brain injuries in dogs.
Asunto(s)
Babesiosis/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Enfermedades de los Perros/diagnóstico por imagen , Animales , Medios de Contraste/farmacocinética , Perros , Evaluación Preclínica de Medicamentos , Ácido Edético/análogos & derivados , Ácido Edético/farmacocinética , Imagen por Resonancia MagnéticaRESUMEN
Preclinical evaluation of a 0.5 M solution of the manganese(II)- trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetate complex (Mn-DCTA, Cyclomang) has been carried out with a view to substitution of potentially toxic gadolinium-containing paramagnetic contrast agents for clinical MRI routines. The toxicological tests of Mn(II)-DCTA were performed on mice and rats. Liquid phantoms were used for evaluating the relaxivity of Mn(II)-DCTA in comparison to that of Gd(III)-DTPA and Mn-DTPA. The diagnostic imaging properties of Mn(II)-DCTA were quantitatively assessed on dogs with cerebral meningeomas (n = 10). The LD50 upon single administration in rats was above 17 ml/kg, thus slightly exceeding the corresponding values for of Gd(III)-DTPA and Mn-DTPA. The relaxivity of Mn(II)-DCTA amounted to R1 = 3.68 (mM(-1) x s(-1)) and did not differ significantly from the values known for Gd-DTPA and Mn-DTPA. Mn(II)-DCTA ensured high-intensity contrast of tumor areas in brain of dogs. It is concluded that Mn(II)-DCTA can be employed as a paramagnetic contrast agent in routine MRI studies and is worth further clinical evaluation.