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

Objective: 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. Current guidelines recommend screening infants with cranial ultrasound (CUS); however, this is prone to missing subtle injury patterns, particularly within the posterior fossa. The present report sought to discuss the utility of diffusion tensor imaging (DTI) in preterm infants. 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, DTI use, and 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, whereas 6 demonstrated structural segregation and asymmetrical white matter myelination in these infants. Seven studies documented concurrent CUS use with 2 studies comparing DTI findings with 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 fractional anisotropy values on initial DTI were associated with cognitive, language, and motor delays. Conclusions: Although DTI is more sensitive for picking up subtle injury patterns, CUS remains the standard of care when screening for injuries that would necessitate surgical intervention. DTI offers a refined understanding of the sequelae of GMH-IVH with microstructural changes found on DTI being associated with childhood motor and cognitive outcomes.