Evaluation of Role of Magnetic Resonance Imaging in Newborns with Suspected Hypoxic Ischaemic Injury and its Association with Clinical Staging: A Cross-sectional Study

Introduction: Hypoxic Ischaemic Injury (HII) also known as Hypoxic Ischaemic Encephalopathy (HIE) is one of the most common causes of neonatal morbidity and mortality in most countries of the world. Perinatal asphyxia being the most frequent cause of HII, some of its long-term sequelae includes impaired neurological development, cerebral palsy, recurrent seizures, etc. Magnetic Resonance Imaging (MRI) has been found to be most sensitive in detecting lesions in the brain of neonates with HII.

Aim: To evaluate the role of MRI in assessing neurologic damage in newborns with suspected HII and its association with clinical staging.

Materials and Methods: An institution-based descriptive cross-sectional study was conducted in a tertiary care Government Hospital in Guwahati, Assam, India for a duration of 15 months from May 2017 to July 2018 on 50 neonates with history of perinatal asphyxia. Assessment of conventional T1 and T2 weighted images, Diffusion Weighted Imaging (DWI) and Susceptibility Weighted Imaging (SWI) was done and association of MRI findings with gestational maturity, Appearance, Pulse, Grimace, Activity and Respiration (APGAR) scores and clinical staging (Sarnat and Sarnat Staging system) was studied.

Results: In majority of cases with clinically mild HII, MRI findings were either normal or of mild degree whereas in cases of clinically advanced stages of HII, MRI findings were moderate-to-severe, suggesting a positive association between clinical grading and severity of brain injury. Term neonates sustained injuries mostly in cortical-subcortical/watershed zones of brain whereas preterm neonates were seen to sustain mainly periventricular lesions. Basal ganglia, thalamic and midbrain lesions were seen to be associated with severe degree of HII in term neonates whereas germinal matrix haemorrhage was observed in preterm neonates with severe HII. A positive association was seen between severity of brain lesions with both low APGAR scores and gestational prematurity.

Conclusion: MRI is helpful to study the pattern of brain involvement in term and preterm neonates with suspected HII and to assess the severity of injury. MRI findings are seen to correlate well with clinical staging.