A brain hemorrhage is bleeding inside the skull that requires immediate medical action. Because the skull encases the brain in a fixed space, any accumulation of blood quickly raises pressure, which can damage brain tissue. Rapid diagnosis of the presence, location, and extent of this bleeding is necessary for patient survival and recovery. A Computed Tomography (CT) scan is the primary tool used in emergency settings to quickly assess a patient suspected of having a brain hemorrhage.
Identifying Brain Hemorrhage Types
Brain hemorrhages are classified by their location within the intracranial vault. One major classification is the Intraparenchymal Hemorrhage (ICH), which involves bleeding directly into the brain tissue itself. This type often results from chronic high blood pressure, where small, weakened arteries rupture deep within the brain.
The other major type is a Subarachnoid Hemorrhage (SAH), where bleeding occurs in the subarachnoid space, the area filled with cerebrospinal fluid surrounding the brain. SAH is most frequently caused by the rupture of a cerebral aneurysm. Trauma is also a common cause for intracranial bleeding, such as epidural or subdural hematomas. Rapid identification of the specific type and location is necessary because the required medical intervention varies significantly.
CT Scan: The Diagnostic Tool
Computed Tomography is the preferred initial imaging technique for suspected brain hemorrhage due to its speed and widespread availability in emergency departments. The procedure is quick, often taking only a few minutes, which is an advantage when a patient’s condition can deteriorate rapidly. A non-contrast CT scan is used because it does not require the injection of an iodine-based dye, avoiding preparation delays. The scan works by passing thin X-ray beams through the head from multiple angles, with detectors measuring radiation absorption by different tissues.
CT is effective for detecting acute hemorrhage because fresh blood appears hyperdense, or bright white, on the grayscale image. Acute blood absorbs X-rays more effectively than surrounding brain tissue. This high density makes fresh blood immediately visible against the darker gray and white matter of the brain, allowing clinicians to quickly confirm the presence of bleeding. Other imaging modalities like Magnetic Resonance Imaging (MRI) are more sensitive for subacute or chronic bleeding but are often too time-consuming for the initial emergency assessment.
Interpreting the Images and Triage
Once the CT images are generated, medical professionals analyze several features to determine the severity of the hemorrhage and guide treatment. The first step is confirming the location of the hyperdense blood, which identifies the type of hemorrhage, such as blood pooled in the subarachnoid space or within the brain parenchyma. The size and volume of the hemorrhage are then measured, as a larger bleed correlates directly with a worse prognosis and a higher likelihood of requiring surgery.
A major focus of the interpretation is identifying mass effect, which describes the impact the blood clot has on surrounding brain structures. This effect is visualized when the hemorrhage causes swelling and displacement of brain tissue, often seen as the effacement, or compression, of fluid-filled spaces like the ventricles and cisterns. Extreme mass effect can lead to midline shift, where the brain tissue is pushed across the center line of the skull, signaling a severe threat to life.
Based on these findings, the patient is triaged to determine the urgency and type of medical response. A small, stable bleed might only require intensive monitoring, while a large hemorrhage with significant mass effect necessitates immediate consultation with a neurosurgeon for potential surgical clot removal.