Computed tomography limitations and the emerging role of blood biomarkers in mild traumatic brain injury

Abstract

Background: Mild traumatic brain injury (mTBI) accounts for the majority of traumatic brain injury presentations in emergency departments, yet its diagnostic assessment remains challenging because clinically significant intracranial lesions are relatively uncommon, while missed injuries may still lead to important clinical consequences. Computed tomography (CT) is therefore routinely used as the first-line imaging modality due to its rapid acquisition, broad availability, and established utility in detecting acute hemorrhage. However, concerns persist regarding its low diagnostic yield when applied to broadly selected mTBI populations and its inability to detect subtle or non-hemorrhagic brain injuries that may be associated with persistent symptoms and functional impairment. Objective: This study aimed to critically evaluate the limitations of CT in mTBI and to analyze the potential role of blood biomarkers as complementary tools to improve imaging triage and clinical decision-making. Methods: A structured literature review was conducted using PubMed, Scopus, and Web of Science, prioritizing English-language studies published within the last ten years that addressed CT utilization in emergency settings, diagnostic yield in mTBI, radiation exposure implications, and the clinical validation of blood biomarkers. Original studies, systematic reviews, and multicenter cohort studies assessing biomarkers such as glial fibrillary acidic protein (GFAP) and ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) were included, and the evidence was qualitatively synthesized according to diagnostic performance and clinical applicability. Results: Available data from large emergency department cohorts indicate that traumatic intracranial hemorrhage is identified in approximately 8% of patients with mTBI undergoing CT, demonstrating the mismatch between high imaging utilization and relatively low rates of positive findings. This practice contributes not only to unnecessary radiation exposure but also to greater healthcare costs and emergency department burden. In parallel, studies evaluating GFAP and UCH-L1 suggest that these biomarkers present high sensitivity and very high negative predictive value for CT-detectable intracranial injury, supporting their potential use in identifying patients at low risk who may safely avoid immediate CT scanning. Conclusion: Overall, current evidence supports a more refined and multimodal diagnostic strategy integrating structured clinical evaluation, selective imaging, and biomarker-informed assessment in order to improve efficiency, safety, and resource allocation in mTBI management.