Development of a screening MRI for infants at risk for abusive head trauma.

Background: Abusive head trauma (AHT) is an important cause of morbidity in infants. Identifying which well-appearing infants are at risk for AHT and need neuroimaging is challenging, and concern about radiation exposure limits the use of head CT. Availability of an MRI protocol that is highly sensitive for intracranial hemorrhage would allow for AHT screening of well-appearing infants without exposing them to radiation.

Objective: To develop a screening MRI protocol to identify intracranial hemorrhage in well-appearing infants at risk for AHT.

Materials And Methods: Infants enrolled in a parent study of well-appearing infants at increased risk for AHT were eligible for the current study if they underwent both head CT and conventional brain MRI. A derivation cohort of nine infants with AHT was used to identify sequences that provided the highest sensitivity for intracranial hemorrhage. A validation cohort of 78 infants including both controls with normal neuroimaging and cases with AHT was used to evaluate the accuracy of the selected sequences.

Results: Three pulse sequences - axial T2, axial gradient recalled echo (GRE) and coronal T1-W inversion recovery - were 100% sensitive for intracranial hemorrhage in the derivation cohort. The same sequences were 100% sensitive (25/25) and 83% specific (44/53) for intracranial hemorrhage in the validation cohort.

Conclusion: A screening MRI protocol including axial T2, axial GRE and coronal T1-W inversion recovery sequences is highly sensitive for intracranial hemorrhage and may be useful as a screening tool to differentiate well-appearing infants at risk for AHT who should undergo head CT from those who can safely be discharged without head CT. Additional research is needed to evaluate the feasibility of this approach in clinical practice.