Evaluating a novel MR imaging biomarker for retinal hemorrhage

Abstract

Background: Dilated fundus examination is the clinical reference standard for retinal hemorrhage diagnosis. Obtaining a timely examination may be challenging in emergent and inpatient settings, and retinal hemorrhage may go undetected. An imaging biomarker is therefore desirable.

Objective: To evaluate the frequency of ringlets of hyperintensity in orbital fat on axial fat-suppressed T2-weighted fast spin echo MR images in children with ophthalmologically-confirmed retinal hemorrhage and in a comparison group of children with benign macrocrania.

Materials and methods: This retrospective single-center study included cases aged > 6 weeks- < 3 years with ophthalmologist-confirmed retinal hemorrhage from 07/2011-12/2019 who underwent full brain MR imaging and reference patients aged > 6 weeks- < 3 years with benign macrocrania who underwent brain MR imaging during the same period. Images were reviewed by two pediatric neuroradiologists blinded to patient group; a subset was randomly selected for duplicate reads. Descriptive data were tabulated for each reviewer and adjudicated results.

Results: After adjudication, ringlets were observed in at least one eye in 67/70 retinal hemorrhage cases (96%) and 3/74 benign macrocrania patients (4%; P < 0.0001). Similar results were observed upon stratification by presence of visible retinal hemorrhage on imaging, and by magnet strength. Intrarater reliability and interrater reliability were high (all κ ≥ 0.86), with concordance rates ≥ 93% across duplicate reads.

Conclusion: Ringlets of hyperintensity are present at high frequency in children with confirmed retinal hemorrhage and are neither an MR imaging artifact, nor a normal developmental finding in infants and young children. As such, they may aid in retinal hemorrhage detection following abusive head trauma.

Keywords: Biomarker; Craniocerebral trauma; Magnetic resonance imaging; Pediatrics; Retinal hemorrhage; Screening; Sensitivity and specificity.