[Logistic regression analysis on risk factors of neonates T1WI hyperintensity at globus pallidus and subthalamic nucleus].

OBJECTIVE: To determine risk factors of T1WI high signal intensity at globus pallidus and subthalamic nucleus (GP and STN) of neonates.

METHODS: Brain MR images of 186 neonates with intact clinical files were retrospectively reviewed to identify whether there were T1WI high signal intensity at GP and STN. Among them, 15 neonates received followed-up MR imaging in 1-5 months after first MR examination. Statistic comparison of clinical features between neonates with and without T1WI high signal intensity at GP and STN were performed using univariate analyses. Then, multiple Logistic regression analysis was used to identify the risk factors of T1WI high signal intensity at GP and STN among those factors which were statistical significant at univariate analyses. ROC curve was employed to determine the cut-off value of the risk factors.

RESULTS: T1WI high signal intensity at GP and STN was identified in 74.2% neonates (138/186). At univariate analyses, the following factors were found with statistical difference between neonates with and without T1WI hyperintensity at GP and STN: transcutaneous bilirubin (TCB), (132±62) vs (91±55) µmol/L (t=3.935, P<0.01); gestational age, 36.0±2.6 weeks vs 34.8±3.4 weeks (t=2.263, P=0.027); age, 9±5 days vs 19±7 days (t=8.992, P<0.01). Multiple Logistic regression analysis revealed a significant negative contribution of age to T1WI hyperintensity at GP and STN (OR=0.795, 95% CI 0.739-0.856, P<0.01). T1WI hyperintensity at GP and STN was seen in the fifteen neonates with followed-up MRI at the first MR imaging. It was disappeared in the followed-up MR imaging and all the neonates developed well without any remarkable abnormalities at physical examinations. ROC curve determined the cut-off value of age was 20 days (The incidence of T1WI high signal intensity at GP and STN was 16.0% in neonates>20 days and 83.2% in those ≤20 days, respectively χ2=51.084, P<0.01).

CONCLUSIONS: T1WI high signal intensity at GP and STN of neonates' brain MR imaging is common, and is related to their age at examination. It should be regarded as a transient phenomenon instead of a sign of kernicterus and asphyxia.