Background: Dilated fundoscopic exam is considered the gold standard for detecting retinal hemorrhage, but expertise in obtaining this exam is not always immediately available. MRI can detect retinal hemorrhages, but correlation of the grade or severity of retinal hemorrhage on dilated fundoscopic exam with retinal hemorrhage visibility on MRI has not been described.
Objective: To determine the value of standard brain protocol MRI in detecting retinal hemorrhage and to determine whether there is any correlation with MR detection of retinal hemorrhage and the dilated fundoscopic exam grade of hemorrhage.
Materials and methods: We conducted a retrospective chart review of 77 children <2 years old who were seen for head trauma from April 2007 to July 2013 and had both brain MRI and dilated fundoscopic exam or retinal camera images. A staff pediatric radiologist and radiology resident reviewed the MR images. Retinal hemorrhages were graded by a chief ophthalmology resident on a 12-point scale based on the retinal hemorrhage type, size, location and extent as seen on review of retinal camera images and detailed reports by ophthalmologists. Higher scores indicated increased severity of retinal hemorrhages.
Results: There was a statistically significant difference in the median grade of retinal hemorrhage examination between children who had retinal hemorrhage detected on MRI and children who did not have retinal hemorrhage detected on MRI (P = 0.02). When examination grade was categorized as low-grade (1-4), moderate-grade (5-8) or high-grade (>8) hemorrhage, there was a statistically significant association between exam grade and diagnosis based on MRI (P = 0.008). For example, only 14% of children with low-grade retinal hemorrhages were identified on MRI compared to 76% of children with high-grade hemorrhages. MR detection of retinal hemorrhage demonstrated a sensitivity of 61%, specificity of 100%, positive predictive value of 100% and negative predictive value of 63%. Retinal hemorrhage was best seen on the gradient recalled echo (GRE) sequences.
Conclusion: MRI using routine brain protocol demonstrated 61% sensitivity and 100% specificity in detecting retinal hemorrhage. High-grade hemorrhage was more often detected on MRI than low-grade hemorrhage, 76% vs. 14%. GRE images were the most sensitive for detection of retinal hemorrhages. A dilated fundoscopic exam can be difficult to obtain in infancy, especially in critically ill or non-sedated children. MRI is a useful modality for added documentation of retinal hemorrhage and can be used as an alternative exam when ophthalmologic expertise or retinal camera images are unavailable. Additionally, identification of retinal hemorrhage on MRI can raise the possibility of abuse in children presenting with nonspecific findings.