MRA Brain Scan in Delhi 2026 — Aneurysm & Stroke

If your doctor has advised an MRA of the brain, the question behind it is almost always about the blood vessels rather than the brain tissue itself — an aneurysm, a narrowing, a malformation, or the vascular cause of a stroke or a persistent headache.

The most useful thing to understand upfront is that an MRA brain usually needs no radiation and no injection at all. That single fact is why it has become the standard study for screening people at risk of aneurysms, and for following a known vascular finding over years without accumulating dose.

But there is an equally important flip side, and this page will not hide it: there are situations where an MRA is the wrong study and a CT is the right one — including one genuine emergency. That section is below, and if you have a sudden severe headache right now, please read it first.

If you have a sudden, severe “worst ever” headache, do not book an outpatient MRA

This has to come before everything else, because getting it wrong is dangerous.

A headache that comes on abruptly and reaches maximum intensity within seconds to a minute — often described as a thunderclap, or as the worst headache of your life — can be a subarachnoid haemorrhage from a ruptured aneurysm. That is a medical emergency, and the correct pathway is an emergency department, not a scan appointment.

In that situation the first-line test is a plain CT of the head, done immediately, because fresh blood in the subarachnoid space shows up on non-contrast CT far more reliably than on MRI in the first hours. Depending on timing and findings, a lumbar puncture or a CT angiogram follows. An MRA booked for next week does not help; it delays the only thing that does.

Our page on the NCCT head scan describes that emergency study. The rest of this page is about the planned use of MRA — screening, investigation and follow-up — which is a completely different clinical situation.

What an MRA brain scan actually is

MRA stands for magnetic resonance angiography. It is an MRI technique that produces images of blood vessels rather than of solid tissue. An MRA of the brain — often written as MRA brain, intracranial MRA, or MR angiography of the circle of Willis — maps the arteries that supply the brain.

The elegant part is how it does this without any dye. The most widely used intracranial technique is three-dimensional time-of-flight (TOF). The scanner repeatedly saturates the signal from stationary tissue in the slab being imaged, so that static brain, bone and fat become dark. Blood flowing into that slab from outside has not been saturated, so it arrives carrying full signal and appears bright. Moving blood lights up simply because it is moving. No contrast agent is needed at all.

The raw data is then reconstructed into projections that look like an angiogram, and the radiologist can rotate the vessel tree in three dimensions to look at a suspicious spot from every angle.

Some studies use contrast-enhanced MRA instead, where gadolinium is injected and imaging is timed to its passage through the arteries. This is used more often for the neck vessels and the aortic arch than for the intracranial circulation. Our page on contrast MRI (CEMRI) explains gadolinium and its precautions.

If your prescription says MRV rather than MRA, that is a venogram — it images the venous sinuses rather than the arteries, and it is the study for suspected cerebral venous sinus thrombosis. The two are not interchangeable, so check which one is written.

Which vessels the scan covers

An intracranial MRA covers the arterial circle at the base of the brain and its main branches:

The internal carotid arteries, including their course through the skull base.
The vertebral arteries and the basilar artery.
The circle of Willis — the ring that connects the front and back circulations.
The anterior, middle and posterior cerebral arteries and their proximal branches.
The anterior and posterior communicating arteries, which are among the commonest sites for aneurysms.

Normal variation here is enormous and usually harmless. A complete, symmetrical circle of Willis is actually a minority finding. Reports frequently mention a hypoplastic (small) vessel, a fetal-type posterior cerebral artery, an absent communicating artery, or vertebral dominance with one side larger than the other. These are anatomical variants, not diseases. They matter only because a surgeon or neurologist needs to know the actual plumbing.

Why your doctor has ordered an MRA brain

Suspected or known intracranial aneurysm — the single commonest reason, whether for first detection or for follow-up of a known one.
Screening someone at increased risk of aneurysm — covered in detail in its own section below.
Arteriovenous malformation (AVM) or dural arteriovenous fistula — abnormal direct connections between arteries and veins.
Stroke or TIA workup — identifying a narrowed or blocked artery as the source, after the acute phase is over.
Intracranial stenosis — narrowing from atherosclerosis, particularly relevant in patients with diabetes, hypertension or a smoking history.
Arterial dissection — a tear in the wall of the carotid or vertebral artery, which classically causes neck pain with neurological symptoms, sometimes after a minor injury, a chiropractic manipulation or even vigorous neck movement.
Moyamoya disease — progressive narrowing of the terminal internal carotid arteries with a characteristic puff-of-smoke network of tiny collateral vessels.
Vasculitis of the central nervous system — inflammation causing beading and irregularity of vessels.
Pulsatile tinnitus — a whooshing sound in time with the heartbeat, which can have a vascular cause.
Trigeminal neuralgia or hemifacial spasm — looking for a vessel loop compressing a cranial nerve where it leaves the brainstem, which changes whether surgery is an option.
Before and after neurosurgical or endovascular treatment — assessing an aneurysm after coiling or clipping, or monitoring a treated AVM.
Unexplained neurological symptoms where a vascular cause needs excluding, alongside a standard MRI brain scan.

In practice, an MRA brain is very often performed in the same sitting as an MRI brain. That combination answers both questions — the tissue and the vessels — in one appointment, and it is usually what a neurologist wants.

Aneurysm screening: who actually benefits

This is where MRA earns its place, and it is worth being precise, because screening the wrong people causes anxiety without benefit.

Unruptured intracranial aneurysms are more common than most people realise, and the large majority never rupture. Finding one creates a genuine dilemma: treating it carries risk, and leaving it carries risk. So screening is recommended only where the probability of finding something that matters is high enough to justify that dilemma.

The groups where screening is generally considered worthwhile include:

People with two or more first-degree relatives (parent, sibling, child) who have had an aneurysmal subarachnoid haemorrhage or a confirmed aneurysm. Family clustering here is real and substantial.
Autosomal dominant polycystic kidney disease (ADPKD), which carries a recognised association with intracranial aneurysms — particularly where there is also a family history of haemorrhage.
Certain connective tissue and genetic conditions, including some forms of Ehlers-Danlos syndrome, and conditions such as fibromuscular dysplasia or coarctation of the aorta.
People with a known aneurysm already treated, who need surveillance for new or recurrent ones.

A single distant relative with a stroke, or a family history of hypertension, is generally not an indication. Whether you should be screened is a decision for your doctor, made on your specific family and medical history — not something to decide from a web page. What this page can do is explain why, when screening is indicated, MRA is usually the chosen tool: no radiation, no injection, and repeatable over decades.

If an aneurysm is found: what the report will tell your doctor

A finding of an aneurysm is understandably frightening, and the report can read like a foreign language. Here is what the radiologist is describing and why each detail matters.

Location. Named by the artery and segment — anterior communicating, posterior communicating, middle cerebral bifurcation, basilar tip, and so on. Location strongly influences both rupture risk and how accessible the aneurysm is for treatment.
Size. Measured in millimetres, usually in two or three dimensions. Size is one of the strongest predictors of behaviour, which is why follow-up scans compare measurements rather than impressions.
Shape. Saccular means a berry-like outpouching on a stalk — the commonest type. Fusiform means a spindle-shaped widening of the whole vessel segment. Lobulated or irregular contours, and a daughter sac or bleb on the dome, are features that generally raise concern.
Neck and dome. The neck is where the aneurysm joins the parent artery; the dome is its far end. A narrow neck is more suited to coiling; a wide neck may need a different approach. This is why the measurement is reported.
Relationship to branches. Whether a branch vessel arises from the aneurysm itself, which matters a great deal to whoever has to treat it.

Two honest caveats. First, MRA is a screening and surveillance tool, not the final word before treatment. When intervention is being planned, a catheter angiogram (DSA) or a CT angiogram is usually performed, because they resolve fine detail better. Second, very small aneurysms — around 3 mm and below — can be missed on MRA, and small ones can also be over-called where vessels loop and overlap. The radiologist mitigates this by rotating the three-dimensional dataset, but the limitation is real and worth knowing.

MRA versus CT angiography: how to tell which one you need

Both map vessels. They are not interchangeable, and the right choice depends on the clinical situation rather than on which is “better”.

Choose CT angiography when speed matters or when detail is critical: acute stroke, where thrombolysis or thrombectomy decisions are measured in minutes; suspected acute subarachnoid haemorrhage; trauma; planning treatment of a known aneurysm; patients who cannot have an MRI because of a device or implant; patients too unwell or restless to hold still. CTA is fast, widely available in emergencies, and better at showing calcified plaque, bone landmarks and the relationship of a vessel to the skull base. The trade-off is ionising radiation and an iodinated contrast injection, with the kidney and allergy precautions that go with it. Our CT brain angiography page covers that study in full.

Choose MRA when the study will be repeated, or when radiation and contrast are best avoided: screening a young person with a family history; following a known unruptured aneurysm over years; a child or adolescent; a patient with iodinated contrast allergy; monitoring a treated AVM; looking for a vessel loop in trigeminal neuralgia. MRA also pairs naturally with an MRI brain in the same sitting, giving tissue and vessel information together.

And there is DSA — digital subtraction angiography — which remains the reference standard. It involves threading a catheter into the arteries and injecting contrast directly. It is invasive and carries a small procedural risk, so it is reserved for cases where the answer must be definitive, or where treatment is being delivered at the same time.

A broader comparison of the two modalities is on our MRI versus CT page.

One more distinction worth making: if the question is about the carotid arteries in the neck rather than inside the skull, the usual first-line test is not MRA at all. It is a carotid Doppler ultrasound — no radiation, no injection, inexpensive, and excellent at grading stenosis at the carotid bifurcation.

How the scan is performed

Safety screening. You complete a detailed form about implants, devices, surgery and metal. This is the most important step of the appointment — details in the next section.
Changing and lockers. All metal, cards and electronics are left outside the scanner room.
Positioning. You lie on your back, head first, with your head resting in a dedicated head coil. Soft pads are placed to stop your head rotating.
Sequences. If an MRI brain is being done in the same sitting, those sequences run first. The 3D TOF angiographic block is then acquired over several minutes.
Staying still. The single most important thing you do. More on this below.
Reconstruction. The angiographic data is reconstructed into rotatable three-dimensional projections at the console.
Contrast, only if required. Most intracranial MRAs are plain. If contrast is needed, a cannula is placed in the arm.

An MRA alone takes roughly 15 to 25 minutes. Combined with a full MRI brain, expect 30 to 45 minutes in the scanner and about an hour for the whole appointment.

Why head movement matters more here than almost anywhere else

In TOF angiography the bright signal is produced by the difference between moving blood and saturated static tissue. If your head moves even slightly during the acquisition, that difference smears. A small aneurysm can be blurred into invisibility, or a loop of normal vessel can be smeared into something that looks like a lesion.

Practically: swallow as little as you can during each acquisition, keep your jaw relaxed and still, do not try to adjust your position between sequences, and if you need to move or cough, press the call button and wait — repeating one block takes a couple of minutes, whereas a blurred study may mean coming back another day.

Safety screening: what you must declare

MRI uses a very strong magnetic field that is on at all times. The concern is not radiation but metal and electronics. Declare all of the following, every time:

Cardiac pacemaker, implanted defibrillator or loop recorder.
Aneurysm clips or endovascular coils in the brain — critically important here, because this is exactly the patient group having an MRA. Most modern clips and coils are MRI-safe, but older ferromagnetic clips are not. Bring your operation notes or implant card.
Cochlear implant or any implanted hearing device.
Implanted pumps and stimulators — insulin pump, deep brain stimulator, spinal cord or vagal nerve stimulator.
Metallic foreign body, especially any history of a metal fragment injury to the eye, or shrapnel.
Heart valve replacements and vascular stents.
Dental implants, plates, screws, rods and joint replacements.
Permanent eye makeup and tattoos, some of which carry metallic pigment.
Pregnancy, particularly in the first trimester.
Kidney disease, if contrast may be needed.
Claustrophobia, so it can be planned for rather than discovered inside the bore.

A declared implant is a manageable problem that the centre will work around. An undeclared one is a safety risk. There is no version of this where it is better not to mention something.

Aneurysm clips, coils and stents: what MRA can and cannot see

If you have already been treated, be aware that metal creates local artefact. A clip produces a bloom of signal loss right where the aneurysm used to be, which is the area the scan is trying to assess. Coils are usually less problematic but still degrade local detail, and flow-diverting stents are difficult to assess on MRA.

This is why post-treatment surveillance is often done with contrast-enhanced MRA, with CT angiography, or with catheter angiography rather than plain TOF — and why your treating neurosurgeon or interventional radiologist should specify which protocol they want. Carry the details of what was implanted.

If closed MRI is difficult for you

A head MRI means your head sits deep inside the bore with a coil around it, which is the hardest configuration for anyone claustrophobic. Say so when you book, not when you arrive — an abandoned scan helps nobody and wastes your day.

An open or wide-bore scanner removes most of the enclosure. Our pages on open MRI in Delhi, open versus closed MRI and choosing an open MRI centre set out the trade-offs honestly, including where a closed scanner still gives better images.

Measures that genuinely help: the first slot of the day, a companion in the room, eyes closed before you enter the bore, the music headphones on, a cloth over the eyes, and the call button in your hand throughout.

Preparation

No fasting for a plain MRA. Eat, drink and take your usual medicines normally.
Complete the safety form carefully, and bring implant documentation if you have any.
Bring previous imaging and reports — earlier MRA, CTA, DSA or MRI brain. For a known aneurysm, the comparison is the whole point of the scan; a new measurement with nothing to compare it against tells your doctor far less.
Bring the prescription with the clinical history on it. Knowing that the indication is “family history of SAH in two siblings” versus “chronic headache” changes how carefully the small vessels are scrutinised.
Remove hair clips, pins and jewellery, and avoid hair products containing metallic particles on the day.
If contrast may be needed, bring a recent kidney function report.
Allow extra time if an MRI brain is being done in the same sitting.

Reading your MRA report: a plain-English glossary

Aneurysm — a localised ballooning of an artery wall. Saccular is berry-shaped; fusiform is a spindle-shaped widening of a whole segment.
Dome and neck — the far end of an aneurysm and the point where it joins the parent vessel.
Daughter sac / bleb — a small outpouching on an aneurysm. Generally regarded as a concerning feature.
Stenosis — narrowing, usually expressed as a percentage or as mild, moderate or severe.
Occlusion — complete blockage.
Flow gap — a break in the bright signal. May mean real narrowing, or may be a technical artefact from turbulent or slow flow. A good report says which it suspects.
Attenuated — thinned or reduced in calibre.
Hypoplastic — congenitally small. Usually a normal variant.
Dominance — one paired vessel being larger than the other, most often described for the vertebral arteries. Normal.
Fetal-type PCA — the posterior cerebral artery arising mainly from the carotid rather than the basilar circulation. A common normal variant.
Tortuosity / ectasia / dolichoectasia — vessels that are unusually winding, widened, or both. Often age-related.
Vessel loop — an artery looping against a cranial nerve. Relevant in trigeminal neuralgia and hemifacial spasm.
AVM nidus — the tangled core of an arteriovenous malformation, with its feeding arteries and draining veins.
Moyamoya pattern — narrowing of the terminal internal carotid arteries with a fine collateral network.
Beading — alternating narrowing and widening along a vessel, which can suggest vasculitis.
Collaterals — alternative routes the circulation has developed around a blockage.

A caution that applies to every MRA report: vascular variants are extremely common and most findings on an MRA are not diseases. A hypoplastic vertebral artery, an incomplete circle of Willis, a tortuous carotid — these turn up constantly in people with no symptoms at all. Take the report to the doctor who ordered it, and resist the urge to interpret single lines in isolation.

Limitations, stated honestly

An MRA is excellent at what it does, but you should know what it does not do well.

Very small aneurysms may be missed, particularly below about 3 mm, and particularly where vessels overlap.
Movement degrades it badly, more than most MRI sequences.
Turbulent and slow flow create artefacts that can mimic narrowing, so a reported stenosis sometimes needs confirming on another modality.
TOF can overestimate the severity of a stenosis, because signal is lost where flow becomes disturbed.
Metal from clips, coils and stents obscures exactly the region of interest after treatment.
It does not show calcified plaque the way CT does, which matters when a surgeon needs to know about the vessel wall itself.
It is not an emergency test for acute haemorrhage or acute stroke. CT is faster and, for fresh blood, more reliable.

None of this makes MRA a poor study. It makes it a specific study, best used for planned investigation, screening and surveillance — and that is exactly where it is unmatched.

After the scan

There is nothing to recover from after a plain MRA. You can drive, eat and return to work immediately. If gadolinium was given, drink water normally and report any delayed rash to your doctor.

Two practical points. Collect a digital copy of the images, not only the printed report — a neurologist or neurosurgeon will want to rotate the three-dimensional dataset rather than look at a flat printout. And keep it carefully. If a vascular finding is being watched over time, this study becomes the baseline against which every future scan is judged, and progression is what drives decisions.

What an MRA brain scan costs in Delhi

The price of an MRA brain in Delhi depends on real variables: whether the MRA is done alone or together with a full MRI brain in the same sitting, whether the intracranial vessels alone or the neck vessels as well are being covered, whether the study is plain time-of-flight or contrast-enhanced, the scanner and protocol used, whether a radiologist’s report and a digital copy are included, and whether you need it urgently or outside normal hours.

Because of that we do not publish a fixed figure here that could be out of date by the time you read it, or that might not match what your prescription actually asks for. The quickest way to get an accurate, all-inclusive number is to send us a photo of your prescription on WhatsApp. You will get today’s actual price for exactly what your doctor has specified — MRA alone or with MRI brain, plain or contrast, report included — along with the next available slot, before you travel.

Send your prescription on WhatsApp for today’s MRA brain price → | Call 9555999960

For a wider view across MRI studies, see our MRI scan cost in Delhi page.

Getting an MRA brain scan in West Delhi

At Edge Imaging & Diagnostics, a NABH-accredited diagnostic centre in Paschim Vihar, West Delhi, an MRA brain is acquired as a dedicated 3D time-of-flight study with rotatable three-dimensional reconstructions, and reported by a radiologist rather than handed over as images alone.

Practical points worth knowing:

Tell us the indication. Aneurysm screening in someone with a family history, post-coiling surveillance, and a trigeminal neuralgia vessel-loop study are three different protocols. The clinical history on the prescription genuinely changes what is acquired.
MRI brain in the same sitting. Most neurologists want both. Booking them together saves a second visit and a second cannula if contrast is needed.
Bring previous studies. For a known aneurysm or a watched finding, the comparison is the most valuable part of the report.
Bring implant documentation if you have had a clip, coil or stent placed.
Open MRI is available if closed scanners are difficult for you.
Everything under one roof — MRI, CT, digital X-ray, ultrasound, Doppler and pathology in the same building. If your doctor also wants a carotid Doppler or an EEG, both can be arranged in the same visit.
Open on Sunday — see our Sunday diagnostic centre page.
CGHS and DGHS empanelled — details on our empanelment page.
Where patients travel from — Paschim Vihar, Rajouri Garden, Tagore Garden, Punjabi Bagh, Janakpuri, Tilak Nagar, Vikas Puri, Moti Nagar, Nangloi and Raghubir Nagar. See our West Delhi diagnostic centre and Rajouri Garden pages.

Frequently asked questions

Is an MRA brain scan painful?

No. A plain MRA involves no injection at all and no sensation from the magnet. The only difficulties are lying still and the loud knocking noise, for which earplugs or headphones are provided. If contrast is required there is one cannula in the arm.

Does an MRA brain need contrast or dye?

Usually not. The standard intracranial technique is three-dimensional time-of-flight, which produces bright blood simply because the blood is moving — no contrast is needed. Contrast-enhanced MRA is used more often for neck vessels, for some post-treatment surveillance, or when the plain study is inconclusive.

Does an MRA use radiation?

No. MRI and MRA use a magnetic field and radio waves, with no ionising radiation. That is the main reason MRA is preferred for aneurysm screening and for repeated follow-up over many years, especially in younger people.

What is the difference between MRA and CT angiography of the brain?

Both map vessels but they suit different situations. CT angiography is faster, more available in emergencies, and better for calcified plaque, bone relationships and fine detail before treatment — at the cost of radiation and an iodinated contrast injection. MRA uses no radiation and usually no injection, which makes it better for screening, for repeated surveillance, for children and for patients with contrast allergy. Acute stroke and suspected acute haemorrhage are CT situations, not MRA situations.

What is the difference between MRA and MRV?

MRA images arteries; MRV images the veins and venous sinuses. MRV is the study for suspected cerebral venous sinus thrombosis. Check which one your prescription actually says, because they are not interchangeable.

Is MRA as good as a catheter angiogram (DSA)?

Not quite. DSA remains the reference standard for fine vascular detail and is what is usually done when treatment is being planned or delivered. But DSA is invasive and carries a small procedural risk, so MRA is the sensible choice for screening, for investigation and for surveillance, with DSA reserved for when a definitive answer is needed.

Can an MRA miss an aneurysm?

Yes, particularly very small ones around 3 mm and below, and particularly where vessels loop and overlap. It can also occasionally over-call a lesion where flow is turbulent. The radiologist reduces this risk by rotating the three-dimensional dataset, but the limitation is genuine — which is why a CT angiogram or DSA is often done before any treatment decision.

Should I be screened for a brain aneurysm because a relative had one?

It depends on how many relatives and how closely related. Screening is generally considered where two or more first-degree relatives have had an aneurysmal subarachnoid haemorrhage or a confirmed aneurysm, and in certain conditions such as autosomal dominant polycystic kidney disease. A single distant relative is usually not an indication. This is a decision for your doctor based on your actual family history, because finding an aneurysm that would never have ruptured creates its own difficult choices.

I have a sudden very severe headache right now. Should I book an MRA?

No. A headache that comes on abruptly and reaches maximum intensity within seconds to a minute can be a subarachnoid haemorrhage, which is a medical emergency. Go to an emergency department. The first-line test is an immediate plain CT of the head, not an outpatient MRA.

Do I need to fast before an MRA brain?

No, not for a plain study. Eat, drink and take your usual medicines normally. The centre will advise you if contrast has specifically been requested.

How long does an MRA brain take?

An MRA alone is usually 15 to 25 minutes. Combined with a full MRI brain in the same sitting, expect 30 to 45 minutes in the scanner and about an hour for the whole appointment including screening and changing.

Can I have an MRA if I have aneurysm clips or coils?

Often yes, but it must be declared and checked first. Most modern clips and coils are MRI-safe, but older ferromagnetic clips are not, so your operation notes or implant card matter. Be aware too that metal creates artefact precisely where the treated aneurysm is, so your surgeon may prefer contrast-enhanced MRA, CT angiography or catheter angiography for post-treatment surveillance.

Can I have an MRA with a pacemaker?

Declare it before anything else. Some modern pacemakers and defibrillators are MR-conditional and can be scanned under specific conditions with cardiology involvement; many older devices cannot. This is decided case by case using your actual device documentation, and a CT angiogram is often the practical alternative.

Can I have an MRA during pregnancy?

Tell the staff before the scan. MRI does not use radiation, which is an advantage, but scanning in pregnancy — particularly the first trimester — still needs a clear clinical justification, and gadolinium contrast is generally avoided. The decision belongs to your treating doctor.

I am claustrophobic. Can I still have a head MRA?

Yes, but plan for it. A head study places you deep in the bore with a coil around your head, which is the hardest configuration. Tell the centre when you book so an open or wide-bore scanner can be used, take an early slot, bring a companion, keep your eyes closed from before you enter, and keep the call button in your hand.

My report says hypoplastic vertebral artery and incomplete circle of Willis. Is that serious?

Almost always no. Both are common normal variants — a complete, symmetrical circle of Willis is actually in the minority. They are reported because a neurologist or surgeon needs to know your actual anatomy, not because they are diseases. Discuss it with the doctor who ordered the scan rather than reading it as a diagnosis.

My report mentions a flow gap. Does that mean a blockage?

Not necessarily. A flow gap is a break in the bright signal, and it can reflect genuine narrowing or simply turbulent or slow flow producing a technical artefact. A careful report usually says which it favours and whether another study is needed to settle it. This is one of the known limitations of time-of-flight angiography.

How soon will I get the report?

Ask when you book. At Edge Imaging & Diagnostics a routine MRA brain report is normally available the same day, with urgent studies reported faster. Carry a digital copy of the images to your neurology appointment — the three-dimensional dataset is far more useful to your doctor than a printout.

Should my follow-up MRA be at the same centre?

Where practical, yes. For a watched aneurysm or vascular finding, the decision often rests on whether anything has changed, and that comparison is most reliable when the protocol and measurement technique are consistent and the reporting radiologist has the previous dataset in front of them.

Medically reviewed by Dr. Nishant Thapar, Consultant Radiologist and Founder, Edge Imaging & Diagnostics, West Delhi. Last reviewed: October 2026.

Disclaimer: This article is general patient information and does not replace a consultation. Imaging findings must always be interpreted together with your symptoms, examination and other tests by the doctor treating you. Decisions about aneurysm screening, surveillance intervals and any treatment belong to your treating neurologist, neurosurgeon or interventional radiologist. MRI safety decisions about implants and devices must be made by the centre and your doctor using your actual implant documentation. A sudden, severe, worst-ever headache is a medical emergency — attend an emergency department rather than booking an outpatient scan.