MRI in mild pediatric traumatic brain injury: diagnostic overkill or useful tool?

Magnetic resonance imaging (MRI) is a sensitive imaging tool which lacks the burden of ionizing radiation. It is not established as primary diagnostic tool in traumatic brain injury (TBI). The purpose of this study was to evaluate the usefulness of MRI as initial imaging modality in the emergency management of mild pediatric TBI.

Children (0-18 years, sub-divided in four age-groups) with mild TBI who received MRI in the emergency department were identified. Clinical characteristics and trauma mechanisms were evaluated retrospectively. Univariate and multivariate logistic regression analyses were used to identify clinical factors that might be indicative for trauma sequelae on MRI scans.

An institutional case series of 569 patients (322 male/247 female; age < 18years; (GCS ≥ 13), who received MRI for mild TBI, was analyzed. Multi-sequence imaging (including T2, T2*, FLAIR, and diffusion-weighted sequences) was feasible without sedation in 96.8% of cases (sedation, 1.8%; general anesthesia, 1.4%). MRI revealed trauma-associated findings in 13% of all cases; incidental findings were detected in 4.7%. In our cohort, GCS deterioration, scalp hematoma, clinical signs of skull base fractures, and horseback riding accidents were related to structural trauma sequelae on MRI.

MRI is a practical primary imaging tool for evaluating children with mild TBI in the emergency department. The presented analyses demonstrated that in our institution, MRI imaging is performed frequently in the emergency department. It resulted mostly in normal findings. This may reflect uneasiness of when to perform imaging in mild TBI and appears retrospectively as an "overdo." There are clinical factors that are more likely associated with MRI-positive findings. Their reliability has to be evaluated in prospective studies in order to formulate further decision rules of when to perform MRI imaging or not.