From the Guidelines
Signs of increased intracranial pressure (ICP) on CT scan include midline shift, ventricular compression, sulcal effacement, cerebral edema, and herniation of brain structures, which are critical to identify promptly as increased ICP is a medical emergency that can lead to brain damage or death if not treated quickly. These findings are often seen in patients with head trauma, brain tumors, infections, or other conditions that might elevate ICP, and can be identified through CT scanning, which is an essential tool in neurological assessment 1.
Key Findings
- Midline shift, where brain structures are pushed from their normal central position due to pressure from one side
- Ventricles may appear compressed or effaced as the brain tissue swells against these fluid-filled spaces
- Sulci (the grooves between brain folds) often appear narrowed or completely effaced
- Cerebral edema presents as areas of decreased density in the brain tissue
- Herniation of brain structures, such as subfalcine herniation (brain tissue shifting under the falx cerebri), uncal herniation (medial temporal lobe displacement), or tonsillar herniation (cerebellar tonsils moving downward)
- The basal cisterns may be compressed or obliterated
- In severe cases, hydrocephalus might develop, showing enlarged ventricles due to cerebrospinal fluid blockage The threshold that defines intracranial hypertension is uncertain but generally is considered to be greater than 20–25 mmHg, although both lower and higher thresholds are described 1.
Importance of Prompt Identification
Increased ICP is a medical emergency that can lead to brain damage or death if not treated quickly, and the radiological signs often precede clinical deterioration, making CT scanning an essential tool in neurological assessment of patients with head trauma, brain tumors, infections, or other conditions that might elevate ICP 1.
From the Research
Signs of Increased Intracranial Pressure on CT Scan
- Sulcal obliteration: This is a sign of elevated ICP, where the sulci (grooves) on the surface of the brain are compressed or obliterated 2.
- Lateral ventricle compression: Compression of the lateral ventricles can be a sign of increased ICP 2.
- Third ventricle compression: Compression of the third ventricle is also associated with elevated ICP 2.
- Midline shift: A shift of the midline structures of the brain can be a sign of increased ICP 2, 3.
- Herniation: Herniation of the brain tissue can be a life-threatening complication of increased ICP 2, 4.
Imaging Characteristics Associated with ICP
- Imaging characteristics such as sulcal obliteration and third ventricular compression are associated with measurements of ICP ≥20 mm Hg 2.
- The presence of all five radiographic signs of elevated ICP (sulcal obliteration, lateral ventricle compression, third ventricle compression, midline shift, and herniation) is associated with poor functional outcome 2.
Automated Estimation of Midline Shift and ICP
- Automated systems can estimate midline shift and ICP based on brain CT images, using features such as texture information, blood amount, and other recorded features 3.
- Machine learning techniques, such as Support Vector Machines (SVMs), can be employed to build prediction models for ICP estimation 3.