Routine imaging of the preterm neonatal brain

Abstract

Routine brain imaging to detect injuries affecting preterm infants is used to predict long-term outcomes and identify complications that might necessitate an intervention. Although magnetic resonance imaging may be indicated in some specific cases, head ultrasound is the most widely used technique and, because of portability and ease of access, is the best modality for routine imaging. Routine head ultrasound examination is recommended for all infants born at or before 31+6 weeks gestation. For preterm neonates born between 32+0 to 36+6 weeks gestation, routine head ultrasound is recommended only in presence of risk factors for intracranial hemorrhage or ischemia. Brain imaging in the first 7 to 14 days postbirth is advised to detect most germinal matrix and intraventricular hemorrhages. Repeat imaging at 4 to 6 weeks of age is recommended to detect white matter injury.

Neuroimaging at Term Equivalent Age: Is There Value for the Preterm Infant? A Narrative Summary

“…In addition, it offers an imaging modality free of exposure to ionizing radiation as opposed to computerized tomography (CT) scans [ 21 ]. A routine imaging schedule for preterm infants less than 32 weeks gestational age (GA) with the cranial US is now followed in neonatal intensive care units (NICU) [ 5 , 18 ]. In order to standardize the descriptions of injury documented on the cranial US, grading systems were developed by Papile et al [ 22 ] Table 1 and Volpe [ 23 ], with that from Papile being the most widely used to date.…”

“…CT has been used to assess for calcifications, hemorrhage, brain injury, and edema secondary to hypoxia-ischemia, venous sinus thrombosis, masses, and structural abnormalities, but this modality is now primarily supplanted by MRI due to the ionizing radiation required for imaging. Except for emergencies, CT scans are now generally avoided for newborn imaging [ 5 ]. Therefore, CT is no longer considered a part of routine imaging techniques of the preterm brain.…”

“…Cranial US remains the NICU’s primary imaging tool worldwide [ 5 , 18 , 56 ]. This is related to its ease of use and cost-efficiency.…”

“…The developing preterm brain is uniquely vulnerable to hypoxic, hemorrhagic, and/or inflammatory injury. The two most frequently reported findings include intracranial hemorrhage and white matter abnormalities (WMA) [ 4 , 5 ]. Both are associated with substantial neurodevelopmental challenges, including cerebral palsy (CP) and mild motor dysfunction, neurosensory impairment, cognitive, language, as well as behavioural disorders such as attention-deficit–hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) [ 6 , 7 , 8 ].…”

“…This narrative summary will review the history and current state of brain imaging, focusing on cranial ultrasound and magnetic resonance imaging (MRI) in the preterm population to predict later neurodevelopmental outcomes. The updated guidelines from the American Academy of Neurology (AAN) [ 17 ], the American Academy of Pediatrics (AAP), and the Canadian Pediatric Society (CPS) [ 5 , 18 ] regarding MRI screening in this population will also be summarized.…”