CT Brain (Plain)
A focused scan for Brain tissue, Bleeds, Skull and more.
Overview
Examines Brain tissue, Bleeds, Skull, Ventricles. Performed at an NABL-accredited Meridian Health centre with a same-day report and a free doctor review.
The full panel
4 areas across 1 groupEvery parameter, grouped by body system — no clicking to expand.
What this scan measures
Thin cross-sectional slices through the brain and skull without any injected dye. It shows fresh bleeding, the size and shape of the ventricles, the skull bones, large areas of established infarction, gross swelling and shift of midline structures.
A plain CT brain is the emergency test. It takes seconds, it is available at any hour, and it answers the question that changes management immediately: is there blood in or around the brain, and is there a skull fracture. It is the standard first scan after head injury, in sudden severe headache, in stroke before clot-busting treatment can be considered, and in altered consciousness.
Symptoms that lead to this scan
- Head injury, particularly with vomiting, confusion or loss of consciousness
- The sudden onset of the worst headache of your life
- New weakness or numbness on one side, or slurred speech
- New seizures, or unexplained confusion in an older adult
- Persistent headache with any neurological sign
Understanding your results
Fresh blood is bright on an unenhanced CT, which is why the test is so good at excluding a haemorrhage — and why a normal scan is genuinely reassuring in that specific question. It is much less sensitive for an ischaemic stroke in the first hours, where the scan can look almost normal while the stroke is unfolding, and for small lesions in the posterior fossa where bone causes artefact. Findings such as 'age-related cerebral atrophy' or 'small vessel ischaemic changes' are common in older adults and are interpreted alongside symptoms, not on their own. Where a tumour, infection or inflammation is suspected, an MRI or a contrast study is usually the next step.
Why the preparation matters
No fasting and no preparation for a plain study. Remove earrings, hairpins, spectacles and any removable dental plate, since dense metal creates streak artefact that can obscure the very area being examined. Tell the team if you are or might be pregnant — a head CT delivers very little dose to the uterus, but the decision is still made deliberately rather than by default.
CT Scan — safety and who should not be scanned
Full CT Scan guideCT uses considerably more ionising radiation than a plain X-ray — the trade for the detail it produces. Published reference figures put a head CT at roughly the background radiation of several months and a chest or abdominal CT at roughly a few years' worth. That is a risk worth taking when the scan will change management, and not worth taking when it will not, which is why CT is requested selectively rather than as a screening test. Modern scanners use iterative reconstruction and automatic dose modulation to keep the exposure as low as the diagnostic question allows.
- Pregnancy
- Always declare it. CT of the abdomen or pelvis delivers a direct dose to the fetus and is avoided unless the scan is genuinely necessary and no alternative — usually ultrasound or MRI — will answer the question. Head and limb CT can sometimes proceed with shielding after a specific discussion.
- Previous severe reaction to iodinated contrast
- A past reaction with rash, swelling, breathing difficulty or collapse must be reported before any contrast study. The scan may be done without contrast, with premedication, or replaced by a different test. Simple warmth, flushing or a metallic taste during a previous injection is a normal sensation, not an allergy.
- Impaired kidney function
- Iodinated contrast is cleared by the kidneys, so a recent creatinine or eGFR is checked before contrast studies. With significantly reduced function the scan may be done without contrast, or with hydration and dose adjustment as directed by the radiologist.
- Metformin, and uncontrolled thyroid overactivity
- Bring your medication list. Metformin is sometimes withheld around a contrast study in people with reduced kidney function, and iodinated contrast can destabilise untreated hyperthyroidism — both are managed with a plan rather than a refusal, provided the team knows.
- Inability to lie still, or claustrophobia
- The bore is short and open, so claustrophobia is far less of a problem than with MRI, but movement blurs the slices and may make a scan non-diagnostic. Tell the team if pain, tremor or anxiety will make stillness difficult; positioning aids and, rarely, sedation can be arranged.
- Table weight and bore limits
- Every scanner has a stated maximum table weight and aperture. Mention any concern when booking so the appropriate scanner is allocated, rather than discovering it on the day.
Who should consider this scan
- Anyone after a significant head injury
- People with sudden severe or thunderclap headache
- Suspected stroke, as the immediate first scan
- Older adults with new confusion, especially on blood thinners
- Anyone with new-onset seizures
Conditions it helps detect
How it works
Patient stories
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