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

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.

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.

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.

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.