Quick answer
A normal CT scan means the scan did not show a fracture, bleeding, bruising or swelling that required attention.[1] It does not rule out a concussion. NINDS states that MRI “is more sensitive and can pick up more subtle brain changes that a CT scan may miss,”[1] and a multicenter study found that 27% of mild TBI patients with a normal CT had an abnormal early MRI.[2]
What CT is used for
According to NINDS, “CT imaging can show a skull fracture and any brain bruising, bleeding, or swelling.”[1] Medical providers use imaging to evaluate the extent of an injury and determine whether surgery is needed.[1] CT is the usual first test because it answers those urgent questions quickly.
How often CT is normal
A 2020 TRACK-TBI study reports that 80% to 90% of TBI patients who come to the emergency department have a mild TBI, and that fewer than 10% of that group have abnormalities on head CT.[3]
MRI after a normal CT
In a prospective multicenter study of 135 people with mild TBI published in the Annals of Neurology, researchers reported that “twenty-seven percent of MTBI patients with normal admission head CT had abnormal early brain MRI.”[2] One or more brain contusions on MRI, and four or more foci of hemorrhagic axonal injury, were each independently associated with poorer outcomes at 3 months.[2]
The limits of all current tests
Even MRI is not definitive. NINDS states that current imaging, blood tests and other measures “can’t always detect damage from mild, concussive injuries.”[1] A concussion is diagnosed clinically, based on how the injury happened and the symptoms and signs that follow.
In a claim
A normal CT is frequently cited by insurers as evidence that no brain injury occurred. The medical sources above describe what CT is and isn’t designed to detect. Records showing the symptoms the person reported, the clinician’s diagnosis and any follow-up testing are what usually establish a concussion. See advanced imaging and blood tests.
Frequently asked questions
Does a normal CT mean I don’t have a concussion?
No. NINDS states that imaging can’t always detect damage from mild, concussive injuries.[1]
Is MRI better than CT for concussion?
NINDS describes MRI as more sensitive than CT for subtle brain changes,[1] but MRI can also be normal after a concussion.
This page provides general information from the sources listed below. It is not legal or medical advice, and reading it does not create an attorney-client or provider-patient relationship. Laws vary by state and change over time. See our legal disclaimer.
Sources
- National Institute of Neurological Disorders and Stroke. “Traumatic Brain Injury (TBI).” https://www.ninds.nih.gov/health-information/disorders/traumatic-brain-injury-tbi
- Yuh EL, et al. “Magnetic resonance imaging improves 3-month outcome prediction in mild traumatic brain injury.” Annals of Neurology, 2013;73(2):224-235. https://pubmed.ncbi.nlm.nih.gov/23224915/
- Okonkwo DO, et al. “Point-of-Care Platform Blood Biomarker Testing of Glial Fibrillary Acidic Protein versus S100 Calcium-Binding Protein B for Prediction of Traumatic Brain Injuries: A TRACK-TBI Study.” Journal of Neurotrauma, 2020. https://pmc.ncbi.nlm.nih.gov/articles/PMC7698990/
Sources last checked: October 11, 2026
