Intracerebral Haemorrhage CT: Essential Imaging Guide and Insights

Important Information Table

Why CT for Intracerebral Haemorrhage?

Non-contrast CT is the first-line investigation for suspected intracerebral haemorrhage (ICH) because it is widely available, fast, and highly sensitive for acute blood. Early identification of ICH is crucial for guiding treatment decisions and preventing complications.

Many stroke-like presentations may be caused by either ischaemic or haemorrhagic stroke. Since treatments differ greatly, rapid and accurate imaging is essential. But why is CT preferred over other imaging techniques?

What Sets CT Apart?

Compared to MRI, CT scanning can be performed in minutes and reliably detects even small amounts of fresh blood within the brain tissue. It is less sensitive to patient movement and available in most emergency settings. MRI can be useful later or if diagnostic uncertainty persists, especially as the blood ages.

Classic CT Appearance of ICH

In the acute phase (up to about 1 week), blood appears hyperdense—that is, noticeably brighter than normal brain tissue—on non-contrast CT scans. The typical ICH appears as a well-defined, bright area within the brain parenchyma, often rounded or irregular in contour.

You might wonder: how can you distinguish ICH from other bright lesions? Surrounding oedema may appear as a darker (hypodense) rim, and mass effect (compression of nearby structures) can help confirm recent bleeding.

Key Features to Recognise

• Hyperdense area within brain tissue (50–100 HU)
• Variable size, sometimes with midline shift or ventricular compression
• No enhancement after contrast in simple acute haemorrhage
• Associated oedema (dark rim) or “finger-like” projections in subacute phase
• Possible presence of intraventricular extension

Identifying ICH on CT: Step-by-Step

Systematic CT review reduces mistakes. Start at the top (vertex) and follow each slice down, scanning for asymmetry, abnormal bright areas, and mass effect. Here’s a basic approach designed for both exams and real-world practice:

Stepwise Approach for CT ICH Detection

1. Check patient/scan data: Confirm non-contrast head CT and correct time interval from symptom onset.
2. Survey for hyperdensity: Look for any abnormally bright signals in brain tissue on each image slice.
3. Assess location: Is the bleed lobar, deep (basal ganglia, thalamus), brainstem, or cerebellar?
4. Evaluate size and shape: Estimate largest diameter and assess for irregular margins.
5. Look for signs of mass effect: Note any ventricular compression, shift of midline, or effacement of sulci.
6. Check for extension: Does the haemorrhage extend into ventricles or subarachnoid space?
7. Consider mimics: Tumours, calcifications, or artefact can sometimes resemble haemorrhage—look carefully for distinguishing features (location, history, absence of mass effect).

It’s easy to miss small or subtle bleeds if you “scan-hop”—always use a systematic and methodical approach.

Classification & Key CT Features

ICH is classified by location: This helps predict underlying cause, prognosis, and treatment urgency. Radiological classification is usually by anatomical site:

• Lobar (cortex, subcortical white matter)
• Deep (basal ganglia, thalamus, internal capsule)
• Brainstem (midbrain, pons, medulla)
• Cerebellar (cerebellum)

Other important CT features:

• Signs of active bleeding: “spot sign” on CT angiogram may predict expansion
• Intraventricular haemorrhage: extension into ventricles, associated with worse prognosis
• Edema and mass effect: indicate severity, influence management
• Chronic ICH: density reduces over time, sometimes blending into brain (isodense)

CT Protocols and Common Pitfalls

Standard Protocols

• Non-contrast CT on initial presentation—most important for acute ICH
• CT angiography if vascular abnormality, aneurysm, or ongoing bleeding suspected
• Repeat CT may be needed if symptoms progress or to monitor expansion

Contrast is not typically used initially, as fresh blood is inherently visible. If the source or ongoing bleeding is uncertain, additional studies may be added.

Pitfalls to Avoid

• Missing subtle or small haemorrhages—always review all image slices
• Chronic blood can become isodense and hard to distinguish from brain
• Calcifications, tumours, or artefacts may mimic haemorrhage
• Confusing intraventricular blood with normal choroid plexus
• Technical issues (motion artefact, incorrect window settings)

Practical Interpretation Tips

Interpretation is a skill built by practice—yet certain habits accelerate learning. Fast, safe decisions require a pattern-based approach, especially in acute care and time-pressured exams.

Quick Reference Checklist

• Always confirm the scan is non-contrast if diagnosing acute ICH
• Look for hyperdensity in classic locations
• Describe size, location, mass effect, and any extension
• Don’t forget to check the brainstem and posterior fossa—small bleeds here can be fatal
• Correlate with clinical scenario—ICH is more likely with sudden focal deficit, headache, or coma

Practice reviewing normal scans as well as a variety of real ICH cases to sharpen your recognition skills—use open-source image libraries or supervised teaching sets wherever possible.

Frequently Asked Questions (FAQ)

How soon after symptom onset can CT detect ICH?

Hyperdense blood is visible on CT within minutes of acute haemorrhage. Sensitivity is highest in the first 24–48 hours, but CT may become less sensitive after 1–2 weeks as blood density decreases.

How do you differentiate ICH from ischaemic stroke on CT?

Acute ICH appears hyperdense (bright), while ischaemic stroke often looks normal or hypodense (dark) in early hours. Clinical context and timing also help guide interpretation.

Can you always see older haemorrhage on CT?

Chronic haemorrhage may become isodense and hard to detect on CT, especially after 2–3 weeks. MRI or repeat imaging may then be necessary if clinical suspicion remains high.

What are common mimics of ICH on CT?

Calcifications, tumours, contrast extravasation, or artefacts can all appear hyperdense. A systematic approach using location, shape, and clinical data helps distinguish these.

When should CT angiography be added?

CT angiography is performed if vascular abnormality, aneurysm, or ongoing active bleeding is suspected—typically for younger patients or when the ICH pattern is unusual.

Takeaway

Mastering intracerebral haemorrhage CT interpretation is essential for any medical or health sciences student. With systematic review, careful attention to classic signs, and understanding of protocols and pitfalls, you can build both exam confidence and clinical competence in this high-stakes area of neuroimaging.

Always remember: this guide provides educational information only—clinical decisions should always involve local protocols, senior supervision, and radiology expertise.