Correlation of Transcranial Ultrasound and Magnetic Resonance Imaging in Evaluation of Imaging Patterns of Clinically Diagnosed Hypoxic Ischaemic Encephalopathy in Neonates

Author(s): Susmita Giri1 , Raman Sau2 , Sudipto Das3 , Runa Das4 , Priyadarshini Sur5 , Ananya Mondal6 , Rajatsubhra Haldar7 , Sudhish Hazra8

BACKGROUND Hypoxic Ischaemic Injury (HII) is an important common cause of neonatal encephalopathy in newborns. Decreased cerebral blood flow and oxygen leads to acidosis, release of inflammatory mediators and excitatory neurotransmitters, and formation of free radicals. Initially, there is primary energy failure followed by a brief period of latency and secondary energy failure. The pattern of brain injury depends on duration, and severity of insult at the time of brain maturation. Clinical staging- Sarnat and Levene classification- was commonly used. Most authors describe a pattern of injury in neonates who are less than 36 weeks’ gestation that is distinct from the pattern in neonates 36 weeks or older. We wanted to determine and compare the role of Transcranial USG and MRI brain, in the evaluation of HIE in neonates with regard to its nature and extent. METHODS Consecutive fifty neonates clinically diagnosed with hypoxic-ischemic encephalopathy (HIE) by Levene’s classification were included. All cases had undergone transcranial ultrasound study of the brain. MRI Brain was performed in all patients after USG and findings were compared. The study was conducted between May 2015 and September 2017. They were collected from the Neonatology Intensive Care Unit (NICU) and Sick Newborn Care Unit (SNCU) at Burdwan Medical College & Hospital, Dept of Paediatrics. RESULTS Our study found that stages I and II showed predominantly mild to moderate HIE, presented with peripheral pattern and with white matter injuries, while stage III revealed severe HIE presented with predominantly central pattern of injury, i.e. Basal Ganglia and Thalamus (BGT). CONCLUSIONS TCUS helps in evaluation of various imaging patterns depending upon gestational age, severity, duration of insult, as depicted above. However, findings need to be corroborated with both conventional and diffusion weighted MRI findings. Both modalities are recommended as diagnostic protocol.