Utility of Diffusion Tensor Imaging in Preterm Infants with Germinal Matrix Hemorrhage and Intraventricular Hemorrhage: A Systematic Review

Introduction: Intraventricular hemorrhage (IVH) and germinal matrix hemorrhage (GMH) are the most common brain injuries in preterm infants. Neonates with these injuries are at greater risk of impaired neurodevelopmental outcome. While current guidelines recommend screening with cranial ultrasound (CUS), this is prone to missing subtle injuries.

Methods: A systematic review of PubMed, Ovid MEDLINE, and Ovid EMBASE was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Included manuscripts were methodically scrutinized for quality; diffusion tensor imaging (DTI) use; neurologic outcome.

Results: Twenty studies with 1574 infants who underwent DTI were included. There were 574 preterm infants with GMH-IVH on DTI. Twelve studies documented decreased fractional anisotropy (FA) while six demonstrated structural segregation and asymmetrical white matter myelination in these infants. Seven studies documented concurrent CUS use with two studies comparing DTI findings to CUS findings. In both studies, DTI more accurately detected presence of GMH, especially within the cerebellum. Among GMH-IVH preterm infants, 58.5% demonstrated cognitive, intellectual, and language delays at follow-up (mean: 32.4 months). Additionally, lower FA values on initial DTI were associated with cognitive, language, and motor delays.

Conclusion : Childhood motor and cognitive outcomes are associated with structural changes influenced by GMH-IVH. DTI may offer a refined understanding of the impact of microstructural changes within GMH-IVH. Studies that compared DTI and CUS accuracy do agree that DTI is more sensitive than CUS and this observation may help guide future clinical practice in select patients.