Written by Ben Thayer, Co-Founder & Co-Owner · 3 min read

Clinical reviewer: Dr. Jon Kimball, MD, Co-Founder, Clinical Lead · Review date added after clinical review

Published

Educational information only. Not medical or legal advice. Questions? Book a 15-minute call or phone 813-709-3771.

Who this is for: Written for patients told their scan was normal and for attorneys and providers explaining what a CT is designed to show.

Key takeaways

  • CT is fast and very good at detecting urgent structural problems such as bleeding, fractures and significant swelling.
  • CT shows structure. It is not designed to measure how well the brain is functioning.
  • Under the 2023 ACRM criteria, a concussion can be diagnosed with normal imaging.
  • When symptoms persist despite normal imaging, standardized functional testing gives the treating provider measured information.
  • A normal first CT does not rule out later problems. Return to the ER for worsening symptoms.

What CT does well

In the emergency department, CT is fast, widely available and very good at detecting problems that may need urgent treatment: bleeding around or within the brain, skull fractures and significant swelling. ER physicians use examination and clinical decision rules to decide when a scan is needed. A normal CT is genuinely reassuring about those urgent structural problems.

A normal CT is genuinely reassuring about urgent structural problems. It does not measure function.

What CT isn't designed to show

An open journal with a pen resting on a blank page
A simple daily symptom log gives the treating provider a clear trend.

CT is a picture of structure. It is not designed to measure how well the brain is working: how quickly someone processes information, how accurately their eyes track, how their attention and memory perform. Under the 2023 ACRM diagnostic criteria, a concussion can be diagnosed without loss of consciousness and with normal imaging. That is why discharge paperwork so often tells patients to follow up if symptoms continue.

Why patients feel confused

Patients told "your scan is normal" sometimes conclude that their ongoing headaches, fog or dizziness must be imagined, or that no one will take them seriously. Explaining that a normal CT rules out certain emergencies but does not measure function helps them understand why follow-up evaluation can still make sense.

Related in this series: Can You Have a Concussion Without Losing Consciousness?, Standardized vs. Subjective Findings in Concussion Cases and Mild TBI vs. Concussion: Are They the Same?. For the full overview, start with our guide, TBI Diagnostics: What Tests and Reports Show.

Where MRI fits

MRI shows more structural detail than CT and may be ordered later by a treating provider in some situations. It is still primarily a structural test. Functional testing answers a different question.

“My CT was normal, but my symptoms continue. What could explain that, and would functional testing help?”

Where functional testing fits

Physician in a white coat speaking with a patient
The treating provider reviews the findings and decides on care.

When symptoms persist despite normal imaging, standardized functional testing of eye movement and neurocognitive performance, with brain-activity measures as one part of a physician-interpreted evaluation, gives the treating provider measured information. A physician reviews the results together with the symptom history. Braintree performs this testing at the provider's office, and a visit typically takes 30 to 60 minutes.

For attorneys

A normal CT in the records does not by itself describe a client's functional status. Read imaging, treating notes and any functional findings together. Our reports do not comment on legal significance.

A question to bring to your next visit

Ask your provider: "My CT was normal, but my symptoms continue. What could explain that, and would functional testing help?" That question opens the right conversation.

When to go back to the ER

A normal first CT does not rule out later problems. Return to the ER right away for a worsening headache, repeated vomiting, unusual drowsiness, a seizure, weakness or confusion.

Frequently asked questions

My CT was normal. Could I still have a concussion?

Yes. Under the 2023 ACRM criteria, a concussion can be diagnosed with normal imaging.

Should I ask for an MRI?

That's a decision for your treating provider.

What does functional testing add?

It measures how the brain is working, such as eye movement and cognition, which CT is not designed to show.

Related reading:
How mobile testing works Concussion & TBI testing For patients Service areas concussion and return to driving spanish speaking patients concussion testing

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Sources

This article is educational and is not medical or legal advice. If this is a medical emergency, call 911.