Table 1. Key studies discussed in the systematic review.

TBI: traumatic brain injury, SWI: susceptibility-weighted imaging, CT: computed tomography, SAH: subarachnoid hemorrhage, MRS: magnetic resonance spectroscopy, GFAP-BDP: glial fibrillary acidic protein and its breakdown products, AUC: area under the curve, FLAIR: fluid attenuated inversion recovery, MRI: magnetic resonance imaging

Lead author	Study type	Population	Sample size	Key findings	Clinical relevance
McMahon et al., 2015 [9]	Multi-center, prospective, cohort study	Patients aged 16-93 years presenting with suspected TBI	215 patients	GFAP-BDP demonstrated very good predictive ability for intracranial injury on CT (AUC=0.87). It showed significant discrimination of injury severity with an odds ratio of 1.45 (95% CI, 1.29-1.64). Using GFAP-BDP could reduce unnecessary CT scans by 12-30% when used alongside other clinical information.	GFAP-BDP can help in establishing or excluding the diagnosis of radiographically apparent intracranial injury across the spectrum of TBI and may reduce unnecessary imaging procedures.
Sigmund et al., 2007 [10]	Comparison of neuroimaging modalities in pediatric TBI	40 children with TBI	40 patients	T2, FLAIR, and SWI MRI sequences showed no significant difference in lesion volume between normal and mild outcome groups but did indicate significant differences between normal and poor and between mild and poor outcome groups. CT revealed no significant differences in lesion volume between any groups.	MRI techniques (T2, FLAIR, SWI) are more effective than CT in assessing the severity of brain injuries in pediatric patients and predicting long-term outcomes. CT remains crucial for acute assessments to determine the need for neurosurgical interventions.
Wu et al., 2010 [11]	Comparison of SWI and CT for evaluating traumatic SAH	20 acute TBI patients with SAH identified by CT	20 patients	SWI identified 55 areas of SAH, matching CT findings, and detected 13 additional areas not seen on CT. CT identified 10 areas not visible on SWI. SWI was particularly effective in highlighting the unique morphology and signal intensity of SAH, showing five more cases of intraventricular hemorrhage than CT.	SWI provides complementary information to CT in detecting small amounts of SAH and intraventricular hemorrhage, demonstrating its potential for detailed assessment in TBI cases. SWI's sensitivity to blood products offers a nuanced view of hemorrhage that can enhance diagnostic accuracy and inform clinical decisions. SWI can be a valuable addition to standard CT imaging in the evaluation of traumatic subarachnoid hemorrhage.
Garnett et al., 2000 [12]	MRS study comparing cellular damage in normal-appearing white matter in head-injured patients	19 head-injured patients who were clinically stable post-TBI	19 patients	The study found a reduced N-acetylaspartate/creatine ratio and an increased choline/creatine ratio in the normal-appearing white matter of TBI patients compared to controls, correlating with injury severity. Even mildly injured patients showed significant alterations in these biomarkers.	Proton MRS provides valuable insights into the metabolic changes in white matter following TBI that are not visible on conventional MRI, offering a potential tool for early detection of cellular damage that could predict long-term neurological outcomes. This technique can be particularly useful in assessing patients with mild to moderate injuries who may experience delayed symptoms.