Neuroimaging in Neonates: Newer Insights

Neuroimaging plays a key role in management of critically ill neonates with neurological problems. Magnetic Resonance Imaging (MRI) is the most commonly used neuroimaging modality in evaluation of neonatal encephalopathy even though other modalities like Cranial Ultrasound (CUS) and Computerised Tomography (CT) scan are available, because MRI provides better image quality and accurate delineation of the lesion. Newer modalities of MRI like Diffusion Weighted Imaging (DWI), Diffusion Tensor Imaging (DTI) are useful in identifying the brain lesion and also in predicting the neurodevelopmental outcome. Magnetic Resonance Angiography (MRA) and Magnetic Resonance Venography (MRV) are used to assess the cerebral arteries and veins with or without the use of contrast material. Arterial Spin Labelling (ASL) MRI and Phase Contrast (PC) MRI are newer modalities of MRI used to assess the cerebral perfusion without the use of contrast material. Magnetic Resonance Spectroscopy (MRS) is a functional MRI modality used to assess the level of brain metabolites which help us in diagnosing neuro metabolic disorders, peroxisomal disorders and mitochondrial disorders. Several predictive scores are available based on the size and location of lesions in MRI, and these scores are used to predict the neurodevelopmental outcome in term neonates with encephalopathy. MRI at term equivalent age in preterm neonates used to predict neurodevelopmental outcome in later life. Even though MRI requires stronger magnetic field and time consuming which limits its usage in critically ill neonates, these limitations were overcame with the availability of MRI compatible ventilators and newer sequences requiring lesser time for image acquisition