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Analyzing CT images of the head
Last reviewed: 03.07.2025
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Each doctor determines the sequence of examination of the obtained images. There is no "only correct" tactic. The radiologist is free to choose between several generally accepted methods. But a clear sequence of image analysis has the advantage that small details are not missed. This is especially important for novice doctors.
The examination of the sections begins with an assessment of the size of the ventricles and the SAP in order to immediately exclude a volumetric formation that threatens the patient's life. It should be taken into account that the width of the SAP increases with age. Then it is necessary to carefully assess the border between the gray and white matter of the brain. A veiled border is a sign of cerebral edema. If pathological changes are suspected, then the adjacent sections should be carefully examined in order to avoid incorrect conclusions due to a possible private volume effect.
[ Recommendations for the analysis of a CT scan of the head
Age (this determines the width of the SAP/brain atrophy)
Anamnesis:
- risk factors
- (trauma -> possible intracranial hematoma)
- (arterial hypertension, diabetes, smoking -> arterial stenosis, stroke)
Signs of a space-occupying neoplasm:
- configuration of the IV ventricle (located behind the bridge)
- configuration of the third ventricle (located between the thalamuses, narrow/slit-like)
- symmetry of the lateral ventricles (concave outer contour of the anterior horns and central part)
- displacement of midline structures (sign of space-occupying lesion)
- preservation of the basal cistern (the quadrigeminal cistern in the form of a "smile on the face"/Batman figure)
- cerebral cortex <-> clear demarcation of white matter from gray matter (blurred border - a sign of edema)
- compliance of SAP width with age
Focal lesions:
- non-enhancing with contrast: differential diagnosis of physiological calcifications (vascular plexuses, pineal gland/private volume) with dense areas of hemorrhage (differential diagnosis of hemorrhage types)
- when contrasted, increasing: a sign of a violation of the blood-brain barrier (due to a tumor, metastases, inflammatory changes)
Pathological changes in bones:
- A control examination of the vault and base of the skull is performed in the bone window to exclude foci of osteolysis/contact destruction due to tumor infiltration
- in patients with trauma, fractures are excluded (especially of the base and facial part of the skull - differential diagnosis with interosseous sutures)