Patient guide · Diagnostic imaging
MRI scanning, how modern magnetic resonance imaging works — from brain to knee to prostate.
A patient-facing guide to how modern MRI scanning works — sequences, contrast options, common indications (brain, spine, joints, prostate, breast), and how to prepare. Radiation-free, sub-millimetre soft-tissue detail.
Key facts about MRI scanning
- 01
Definition
Magnetic resonance imaging — cross-sectional pictures generated using strong magnets and radiofrequency pulses.
- 02
No ionising radiation
Unlike CT or X-ray, MRI uses no radiation — safe to repeat and safe in pregnancy in most circumstances.
- 03
1.5T and 3T standard
1.5-tesla and 3-tesla scanners are the modern standard; 3T offers higher resolution for neuro, prostate and musculoskeletal work.
- 04
Contrast: gadolinium IV
Gadolinium-based contrast is given intravenously when tissue characterisation or vascular detail is needed.
- 05
Metal safety mandatory
Every patient completes a metal-implant safety check before entering the scanner room — no exceptions.
- 06
Consultant radiologist
A subspecialty consultant radiologist reports the study — neuro, MSK, body or cardiac depending on the region.
How an MRI works
From referral to report — what happens, in order.
Seven concrete steps — how modern MRI works from the referral through to the consultant radiologist’s report.
Phase 1 · Before your scan
Referral, screening, preparation
Phase 2 · On the day
~20–40 minutes in the scanner
Phase 3 · After
Consultant radiologist report
- 01
Before
Consultation and referral
A short referral outlining symptoms, prior imaging and the clinical question the MRI needs to answer.
- 02
Before
Metal safety questionnaire
A structured questionnaire on implants, pacemakers, aneurysm clips and prior surgery — completed before the appointment.
- 03
Before
Fast 4 hours if contrast
If gadolinium contrast is planned, fast for 4 hours beforehand. Water and routine medication are usually fine.
- 04
On the day
Change into gown, remove metal
Change into a gown, and remove all metal — jewellery, hairclips, coins, bank cards, hearing aids.
- 05
On the day
Lie in scanner (20–40 min)
Lie on the couch, headphones on, panic button in hand. The scan itself takes 20–40 minutes depending on the region.
- 06
On the day
Sequences acquired
Multiple sequences (T1, T2, STIR, diffusion, post-contrast) build a full picture of anatomy and pathology.
- 07
After
Radiologist report
A consultant radiologist reads the study and issues a structured report to the referring clinician, typically within 24–72 hours.
What it shows
Where MRI is the right test.
MRI’s soft-tissue detail makes it the first-line test across neuro, spine, musculoskeletal, cardiac, prostate and breast pathways.
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Brain MRI
Stroke, multiple sclerosis, tumour, headache work-up, memory disorders.
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Spine MRI
Disc prolapse, spinal cord pathology, sciatica, cauda equina, post-op review.
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Joint MRI (knee, hip, shoulder)
Cartilage, ligaments, tendons, labral tears, cartilage loss, occult fractures.
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Cardiac MRI
Left ventricular function, fibrosis mapping, myocarditis, cardiomyopathy.
-
Prostate MRI (multiparametric)
PI-RADS assessment before biopsy; the first-line test for suspected prostate cancer.
-
Breast MRI
High-risk screening, tumour staging, implant assessment, problem-solving.
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Whole-body diffusion (cancer screen)
Diffusion-weighted whole-body MRI for myeloma, staging and screening pathways.
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Red flag: acute stroke or cord compression — urgent pathway
Acute stroke or suspected cord compression is an emergency — hospital pathway, not a private slot.
Next steps after your MRI
An MRI is a step in a pathway, not the end of one.
What the report unlocks — from reassurance to biopsy, surgical or radiotherapy planning.
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Reassurance if normal
A normal MRI is a genuine result — often the reassurance the clinical picture needed.
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Structured follow-up imaging
Interval MRI at a defined timepoint to characterise a lesion’s behaviour over time.
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Onward specialist referral
Referral to the right subspecialist — neurology, spinal, oncology, cardiology.
-
MDT review
Discussion at a multidisciplinary team meeting — radiologist, surgeon, oncologist, pathologist.
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Biopsy planning
MRI-guided or fusion biopsy planning — prostate, breast, liver, bone.
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Surgical planning
Pre-operative mapping for spine, joint, neurosurgical or oncological resection.
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Radiotherapy planning
MRI-based contouring for high-precision radiotherapy — brain, prostate, head and neck.
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Structured surveillance
A surveillance schedule for known lesions or post-treatment monitoring.
Our vetted London network
A small panel of MRI centres, we picked them.
Partners across central, north, west and south London. Not listed publicly — introductions are made privately, once we understand your case.
Selection criteria
How we choose every MRI centre in our network.
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1.5T or 3T scanners with current-generation coils and protocols
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Subspecialty consultant radiologists (neuro, MSK, body, cardiac)
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Radiographer-led safety screening and gadolinium governance
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Structured, subspecialty-appropriate reports within 24–72 hours
Safety and red flags
Safe by design, with a few important caveats.
MRI has no ionising radiation, but the magnet is always on — and a handful of clinical scenarios need urgent hospital care, not a private slot.
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Metal implant safety
Pacemakers, cochlear implants, aneurysm clips and some older implants may be unsafe — device details must be checked before scanning.
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Claustrophobia
The bore is narrow. Wide-bore or open scanners help; sedation is arranged for severe claustrophobia.
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Renal impairment + gadolinium
Reduced kidney function alters gadolinium choice — eGFR is checked before contrast is given.
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Pregnancy (relative)
MRI is generally safe in pregnancy, but contrast is usually avoided unless the benefit is compelling.
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Contrast anaphylaxis
Anaphylaxis to gadolinium is rare but real — prior reactions are declared and managed.
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Acute stroke
Sudden weakness, facial droop or slurred speech is a 999 call, not a private booking.
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Cord compression
New leg weakness, saddle anaesthesia or bladder/bowel change needs urgent hospital assessment today.
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Suspected malignancy
Where cancer is suspected, MRI usually fits inside a wider staging pathway — not a standalone answer.
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Suspected MS relapse
A relapse of multiple sclerosis is a same-week neurology assessment, with MRI as part of that pathway.
Reading your report
An MRI report can look intimidating. It isn’t.
Whatever the finding, the report keeps to the same four parts.
A quiet reminder
The report is written for your doctor, not for you — and that’s normal.
If you would like us to talk you through it before your follow-up, just ask.
- 01 Header
Indication and clinical question
Your details, the reason for the scan, and the specific clinical question the MRI is being asked to answer.
- 02 Technique
Scanner, sequences and contrast
Field strength (1.5T or 3T), the sequences acquired, and whether gadolinium contrast was administered.
- 03 Findings
Anatomy, region by region
A structured description of the anatomy imaged — normal, abnormal, incidental, with measurements where relevant.
- 04 Impression
The conclusion: read this first
The consultant radiologist’s summary and the concrete next step — read this first.
Recognised by major UK insurers
Cover depends on your policy and clinic; we confirm with your insurer before booking.
Frequently asked
Everything patients ask about MRI scanning.
Quick answers on safety, contrast, field strength, duration and claustrophobia.
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What does an MRI scan show?
MRI produces detailed cross-sectional pictures of soft tissue — brain, spinal cord, joints, muscles, organs. It shows structural changes such as tumours, inflammation, demyelination, cartilage loss, ligament tears and vascular abnormalities in sub-millimetre detail.
-
Is MRI safe? Does it use radiation?
MRI uses no ionising radiation — only strong magnetic fields and radiofrequency pulses. It is one of the safest imaging tests in medicine. The main safety considerations are metal implants, severe claustrophobia and, when contrast is used, kidney function and prior reactions.
-
What is the difference between 1.5T and 3T MRI?
3T scanners have twice the magnetic field strength of 1.5T. That translates to higher signal-to-noise, finer resolution and shorter scans for many indications — particularly neuro, prostate and musculoskeletal work. 1.5T remains excellent for most general applications and is often preferred where implants limit 3T use.
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Do I need contrast for my MRI?
Not always. Contrast (gadolinium) is added when tissue characterisation matters — suspected tumour, active inflammation, infection, vascular disease. Many joint, spine and screening MRIs are done without contrast. The referring clinician and radiologist decide together.
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How long does an MRI take?
Most single-region MRIs take 20–40 minutes in the scanner. Multi-region studies, cardiac MRI and multiparametric prostate MRI take 45–75 minutes. Plan for around an hour at the clinic including check-in and safety screening.
-
What if I’m claustrophobic?
Modern wide-bore scanners help significantly. If claustrophobia is severe, options include prone positioning, oral sedation arranged in advance, or an open/upright MRI at a specialised centre — a trade-off in image quality that a radiologist will weigh against the clinical question.
Sources
Guidelines and standards underpinning this guide.
- Royal College of Radiologists — MRI standards and guidance.
- European Society of Radiology — clinical MRI standards.
- American College of Radiology — MRI appropriateness criteria.
- British Institute of Radiology — MRI safety guidance.
Published 2026-07-30 · Reviewed 2026-07-30 · Next review 2027-07-30 · 6 min read · Clinically reviewed by Pulse Atlas Editorial Board,
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In practice, in London
How MRI scanning tends to unfold when you go private
With MRI scanning, the London question is usually about report turnaround and the radiologist reading it — not whether the scan is available. On the NHS, MRI scanning typically sits behind a triage step and a wait that can stretch from a few weeks into months. In London’s private sector, the same appointment often lands within days. That speed matters when symptoms are disrupting work, sleep, or a plan you’d already committed to — and it’s the single most common reason people call us in the first place.
The mechanics are straightforward: a consultant appointment, any tests done at a nearby CQC-registered site, and a written report back within a few days. London’s density of private diagnostics — Marylebone, the City, Chelsea, Canary Wharf — means most patients can find something that fits around work without a cross-town trek. For MRI scanning specifically, the difference between a routine report and a sub-speciality read is where private care earns its keep.
The value of going through a concierge for MRI scanning isn’t access — anyone with an insurer or a credit card can get a private appointment in London. The value is knowing which consultant reads this particular presentation best, which unit turns reports around fastest, and which pathway won’t hit a dead end if the findings point somewhere unexpected.
Nearby in the library