Can a Blood Test Help Avoid CT Brain After Head Injury?
This systematic review and meta-analysis evaluated whether serum biomarkers can help identify intracranial injury in adults presenting to the Emergency Department with minor head trauma.
Two central nervous system proteins—glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase-L1 (UCH-L1)—are released into the bloodstream following brain injury. When measured together, these biomarkers may help clinicians decide whether a CT brain scan is necessary.
The analysis included 11 studies involving 5,529 adults with a Glasgow Coma Scale (GCS) score of 9 to 15. All patients underwent CT brain imaging, and blood samples were collected within 4 to 24 hours of injury. Only two studies used the Abbott i-STAT point-of-care device; the remainder relied on laboratory-based tests such as ELISA or CMIA.
The combined biomarkers showed excellent sensitivity and negative predictive value (both 100%), making them highly reliable for ruling out intracranial injury. However, specificity was low (29%), meaning many patients with a positive test would not have a CT abnormality. This approach is similar to how D-dimer is used to exclude pulmonary embolism in low-risk patients.
For rural and remote EDs without onsite CT imaging, this testing strategy is especially promising. It could reduce unnecessary interhospital transfers, easing strain on retrieval services and improving patient experience.
However, several limitations remain. The biomarkers must be used in the right clinical context; overuse could lead to unnecessary investigations. And CT may still be required for other injuries, such as cervical spine trauma.
Before implementation, further studies in Australian and New Zealand rural populations are essential. Cost-effectiveness, feasibility of point-of-care testing, and real-world safety data must also be established. Nevertheless, this emerging evidence represents a promising advance toward more efficient, locally delivered care for rural patients with minor head injuries.
First published in the RRECN Newsletter (August 2025).
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