Would CT Or MRI Scan Show Structural Brain Damage?

Posted on Fri, 22 May 2015

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Fri, 22 May 2015 Answered on

Thu, 18 Jun 2015 Last reviewed on

Question : If a person had an injury where he was hit in the forehead with a lead pipe and was knocked to the ground where he hit his head and was knocked out and having a seizure, would a cat scan or MRI not show anything since they weren't done until 9 days later?

Answered by Dr. Olsi Taka (1 hour later)

Brief Answer:
Read below.

Detailed Answer:
I read your question carefully and I understand your concern.

The aim of both the CT or MRI after a traumatic brain injury is to show whether there is a structural brain damage like a hemorrhage or ischemia. They do not tell us anything about whether there is/was a seizure or abnormal electrical activity, that is evaluated by the description of the episode.
If the seizure was right after the hit it is a case of immediate post traumatic seizure. If no changes on CT and MRI these seizures generally do not repeat fortunately as they are not related to a structural damage of the brain but to a transitory physiological response of the brain with temporary altered blood flow leading to an electric discharge. But as I said it is transitory and do not reoccur later.
Whether there is a chance that if imaging was performed earlier than 9 days it might have detected something.... with CT that is a possibility (though it would be a case of a minor change to have resolved that soon, no consequences), with MRI that is not the case, both ischemic and hemorrhagic events would have been visible at a later time as well.

I hope to have been of help.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar