RESUMEN
OBJECTIVES: The objectives of this study were to clarify which biological manganese exposure indices reflect the pallidal signal intensities in magnetic resonance imaging (MRI) in liver cirrhotics. METHODS: We examined whole blood, plasma, RBC and urinary manganese concentrations, as well as, brain MRI in 22 cirrhotic patients and 10 healthy controls. From MRI scans we calculated the signal intensity of the globus pallidus using the pallidal index (PI), the ratio of the globus pallidus to subcortical frontal white-matter signal intensity in axial T1-weighted MRI planes multiplied by 100. In addition, we studied the relationships between PI and other measurements. RESULTS: The high signal intensity in the globus pallidus on T1-weighted MRI was observed in 18 (81.8%) patients. There was a significant correlation between whole blood and RBC manganese concentration, and PI on MRI. According to multiple linear regression, whole blood and RBC manganese concentration reflected PI on MRI better the other indices did. CONCLUSIONS: Whole blood and RBC manganese concentrations could be useful as biological manganese exposure indices that reflect PI on MRI.