A concussion is a mild traumatic brain injury caused by a jolt or blow to the head, or a hit to the body that moves the head and brain rapidly. This sudden movement can stretch and damage brain cells. A CT scan, or computed tomography scan, uses X-rays to create detailed cross-sectional images of the body’s internal structures.
Understanding Concussions
A concussion is primarily a functional brain injury, not a structural one with visible damage. It occurs when the brain moves inside the skull, causing microscopic changes in brain cell function and connections. These changes disrupt normal brain operation but do not typically result in gross structural damage like bleeding or fractures visible on standard imaging. Therefore, the brain’s internal structure often appears normal on a CT scan, despite the functional impairment, as brain cells may not communicate effectively due to the mechanical forces of the injury. Concussions involve a temporary disturbance of brain function, distinguishing them from more severe injuries with observable structural alterations.
How CT Scans Work
CT scans use multiple X-ray beams rotating around the body, capturing images from different angles, which a computer then processes to generate detailed cross-sectional “slices” of internal structures. These scans excel at visualizing dense tissues like bone and significant fluid collections or shifts within the body. The technology detects how different tissues absorb X-rays; dense structures appear white, while less dense areas show up in shades of gray or black. CT scans provide anatomical images, showing the physical structure of the brain and skull. However, they are not designed to detect the subtle, microscopic disruptions in brain cell function that characterize a concussion, as these do not involve large-scale structural damage.
What a CT Scan Reveals After Head Trauma
Even though CT scans do not directly show a concussion, they are invaluable for ruling out more severe and potentially life-threatening brain injuries. After head trauma, a CT scan can quickly identify conditions requiring immediate medical attention, making them a crucial first-line imaging technique in emergency settings.
A CT scan can reveal:
Intracranial hemorrhages, which are types of bleeding inside the skull, including epidural, subdural, and subarachnoid hematomas.
Brain contusions, which are bruises on the brain tissue, appearing as bright areas.
Skull fractures, or breaks in the skull bone, which are clearly visible.
Significant brain swelling that could lead to dangerous pressure within the skull, which may appear as darker regions or shifts in brain tissue.
Diagnosing Concussions
Diagnosing a concussion primarily involves a comprehensive clinical evaluation, as standard imaging like CT scans typically do not show these injuries. Healthcare professionals assess the patient’s symptoms, conduct specific examinations, and gather a thorough medical history. Symptom assessment is a key component, where patients report symptoms such as headache, dizziness, confusion, nausea, light sensitivity, sound sensitivity, or memory issues. A neurological examination evaluates balance, coordination, reflexes, and overall cognitive function. Brief cognitive tests may also be used to check memory, attention, and processing speed.