Usefulness of (1) H-MRS in differentiating bilirubin encephalopathy from severe hyperbilirubinemia in neonates.

Objective: To evaluate the usefulness of (1) H-MRS in differentiating bilirubin encephalopathy from severe hyperbilirubinemia in neonates.

Methods: There were 11 patients enrolled in the neonatal bilirubin encephalopathy (NBE) group, 8 patients in the neonatal hyperbilirubinemia (NH) group, and 9 healthy, age-matched neonates were included as controls. All patients and controls underwent (1) H-MRS and conventional magnetic resonance (MR) sequences. The spectroscopic regions of interest were the bilateral basal ganglia and the thalamus, and a spatial resolution of 1.0 cm(3) was obtained.

Results: Peak-area ratios of NAA/Cr and NAA/ Cho in the basal ganglia were found to be significantly lower for the NBE group compared with the NH and control groups (P < 0.05). In contrast, there was no significant difference in the NAA/Cr ratios calculated for basal ganglia of the NH and control groups. Peak-area ratios of NAA/Cr and NAA/Cho in the thalamus were decreased for the NBE group compared with the NH and control groups, but the differences were not significant (P > 0.05). There was a significant correlation between NAA/Cr ratios for basal ganglia and the total serum bilirubin (TSB) peak level in the NBE group (P < 0.05).

Conclusions: (1) H-MRS is useful in the differential diagnosis of NBE from severe hyperbilirubinemia in neonates, especially when the symptoms of NBE are atypical (subtle) and MRI does not reveal clear abnormalities.