Studying neonatal bilirubin encephalopathy with conventional MRI, MRS, and DWI.

INTRODUCTION: The purpose of this study was to evaluate the diagnostic value of conventional magnetic resonance imaging (MRI), proton magnetic resonance spectroscopy ((1)H-MRS), and diffusion-weighted imaging (DWI) for neonatal bilirubin encephalopathy.
METHODS: We collected conventional MRI in 24 neonates with neonatal bilirubin encephalopathy. We performed (1)H-MRS and DWI sequences to nine of the 24 patients and seven age-matched healthy control subjects. Multiple-voxel (1)H-MRS data were acquired using PRESS pulse sequence with TE = 135 ms and TR = 1500 ms. The spectroscopic regions of interest were the bilateral basal ganglia and thalamus with a 1.0 mL spatial resolution. The data from DWI were collected by using a single shot-spin echo-echo planar imaging sequence with TR/TE: 2900/98, and imaging regions were also focused on the bilateral basal ganglia and thalamus.
RESULTS: Nineteen of the 24 patients had abnormal T(1)-weighted image hyperintensity in the globus pallidus, but these lesions appeared as normal T(2)-weighted image intensity in the same region. Ten of the 24 patients had T(1)-weighted image high signal intensity in the subthalamic nucleus and appeared as normal intensity in the region for the T(2)-weighted images. The peak area ratios of NAA/Cho and NAA/Cr were significantly decreased (t-test, P < 0.05) in the patients compared to the controls in the basal ganglia.
CONCLUSION: Conventional MR imaging and (1)H-MRS are important complementary tools in the diagnosis of neonatal bilirubin encephalopathy. The study provides important information for applying these MR modalities to evaluate neonates with bilirubin encephalopathy.