Timing Is Everything—A Repeat CT Protocol for TBI

Written by Rebecca DiFabio

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Approaches to repeat CT scans in traumatic brain injuries (TBIs) are highly variable. This study recommends a risk-stratified approach based upon injury severity, patients’ clinical factors, and timing of initial CT.

Fickle findings for a common problem
Despite TBIs being a major cause of morbidity and mortality, repeat imaging practices remain disputed. Guidelines are silent about when to perform follow-up imaging, resulting in inconsistent practice patterns. 

This systematic review of 26 studies evaluated timing strategies for repeat CT scans and proposed an algorithm for imaging timing in adult TBI patients. Hemorrhage progression varied widely (0.4–65%), with substantial variability in predictive factors. Consistent radiologic predictors of progression included early initial CT (<2–3 hours post-injury), concomitant subarachnoid (OR 3.28), subdural (OR 4.35), or epidural (OR 1.47) hemorrhages, and CTA contrast extravasation (OR 11.81). Unsurprisingly, clinical factors associated with progression included older age, lower initial GCS, coagulopathy, and antiplatelet use. Progression also correlated with TBI severity, occurring in 0.4–42% of mild (GCS 13-15) and 42.3–61% of moderate-severe cases, with neurosurgical intervention required in 0.13–0.9% of mild cases and 8.9–24% of moderate-severe cases. 

There are multiple limitations to the data used in this review, including no standardized definition of “hemorrhage progression,” a lack of external validation among proposed predictive tools, inconsistent findings for certain risk factors (e.g. some studies found higher rates of progression with smaller initial volumes versus others with larger initial volumes), and undefined best practices for repeat imaging timeframes. 

How does this change my practice?
This study did a great job of reviewing high-risk factors, and the proposed algorithm is a step in the right direction on CT timing to augment validated tools such as BIG. However, more high-quality data is needed. The authors acknowledge the need for large, prospective, multicenter studies with standardized definitions and protocols, and I agree. However, I’ll use still this information, in conjunction with my local department and neurosurgical recommendations, for future TBI patients. 

Source
Timing Is Everything: A Systematic Review of Optimal Repeat Computed Tomography Protocols in Traumatic Brain Injury. J Neurotrauma. 2025 Nov 24. doi: 10.1177/08977151251401545. Epub ahead of print. PMID: 41293885.