MRI Knee
A focused scan for Ligaments (ACL/PCL), Menisci, Cartilage.
Overview
Examines Ligaments (ACL/PCL), Menisci, Cartilage. Performed at an NABL-accredited Meridian Health centre with a same-day report and a free doctor review.
The full panel
3 areas across 1 groupEvery parameter, grouped by body system — no clicking to expand.
What this scan measures
Everything inside the knee that an X-ray cannot show: the anterior and posterior cruciate ligaments, the collateral ligaments, both menisci, the articular cartilage, the patellar and quadriceps tendons, the joint fluid, and the bone marrow underneath the cartilage.
It is the test that decides whether a knee injury needs surgery. Mechanical symptoms — locking, catching, giving way — and a knee that swelled within hours of an injury are the classic reasons, since both point to an internal derangement that examination alone cannot fully characterise.
Symptoms that lead to this scan
- Knee injury with rapid swelling, especially a twisting injury
- A knee that locks, catches or gives way
- Persistent pain despite physiotherapy and rest
- Pain localised to the joint line
- Assessment before arthroscopic surgery
Understanding your results
MRI is sensitive enough to find changes that are not causing symptoms: degenerative meniscal tears and cartilage thinning are common findings in middle-aged and older knees and often coexist with pain that has another source. A tear is therefore treated on the basis of symptoms, examination and function — not because it appears on a scan. Bone marrow oedema, sometimes reported as a bone bruise, indicates recent impaction injury and usually resolves over weeks to months. A radiologist's description is the input to an orthopaedic decision, not the decision itself.
Why the preparation matters
No fasting for a plain knee MRI. The knee is imaged in a dedicated coil and you lie still for around 30 minutes — small movements blur the thin cartilage and meniscal images most of all, so get comfortable before the scan starts. Complete the metal safety questionnaire: most knee implants and screws are MRI-safe, but they must be declared in advance because they create local artefact and, occasionally, because a specific device needs checking first.
MRI — safety and who should not be scanned
Full MRI guideNo ionising radiation is involved — an MRI adds nothing to your lifetime radiation exposure, which is a real advantage in young patients and in repeated follow-up. The risks are entirely different in kind: the magnet is ALWAYS on, even when no one is being scanned, and it exerts strong force on ferromagnetic objects. That is why the screening questionnaire is mandatory, why loose metal must be left outside the room, and why the safety questions are asked more than once. Radiofrequency energy can also warm tissue and, rarely, metallic tattoo pigment or a wire loop; report any heating sensation immediately and the sequence will be stopped.
- Cardiac pacemaker or implantable defibrillator (ICD)
- Many older devices are not MRI-safe and the scan can damage them, alter their programming or heat the leads. Some newer devices are 'MR-conditional' and can be scanned only under a defined protocol with cardiology support. Bring your device identification card and tell the team when you book, not on the day.
- Cochlear implants and other implanted hearing devices
- Cochlear implants contain a magnet and are generally unsafe in an MRI scanner unless the specific model is documented as MR-conditional and the manufacturer's protocol is followed. Middle-ear prostheses and bone-anchored hearing aids also need to be identified and checked.
- Metallic foreign body in the eye
- If you have ever worked with metal grinding, welding or lathe work, or had a metal fragment injury to the eye, say so. A tiny retained ferromagnetic fragment can move in the magnetic field and damage the eye. A plain orbital X-ray is done first to exclude it — this is a genuine, not theoretical, safety issue.
- Aneurysm clips, vascular coils and older heart valve prostheses
- Modern clips and valves are usually MRI-compatible, but older ferromagnetic ones are not, and the consequences of getting it wrong are severe. The exact device, model and implant date must be confirmed from your records before the scan is booked.
- Neurostimulators, insulin pumps, infusion pumps and programmable shunts
- Deep brain, spinal cord and vagus nerve stimulators, implanted drug pumps and programmable hydrocephalus shunt valves all need manufacturer-specific handling — some must be switched off, some reprogrammed afterwards, some preclude the scan entirely. Insulin pumps and continuous glucose sensors are removed before entering the room.
- Pregnancy
- MRI does not use radiation and is used in pregnancy when needed, but scanning in the first trimester is generally avoided unless the benefit is clear, and gadolinium contrast is avoided in pregnancy altogether. Tell the team so the decision is made deliberately.
- Severe kidney impairment, if contrast is planned
- Gadolinium-based contrast is cleared by the kidneys and has been linked with nephrogenic systemic fibrosis in people with severe renal impairment. Kidney function is checked before any contrast-enhanced MRI, and a non-contrast protocol or an alternative agent is used where necessary.
- Severe claustrophobia, or inability to lie still
- The bore is a narrow tube and scans can run to 45 minutes. Say so in advance rather than discovering it inside the scanner: a wide-bore or open scanner, a prone or feet-first position, a mirror, music, a companion in the room, or mild sedation arranged with your doctor can all make the difference between a completed scan and an abandoned one.
- Loose metal, cosmetics and removable items
- Jewellery, watches, hairpins, hearing aids, dentures, piercings, underwired bras, transdermal medication patches (some contain a metallic foil backing and can burn), and metallic-particle makeup or eyelash extensions all come off before you enter the room. Even a hairclip becomes a projectile in a magnetic field.
Who should consider this scan
- Anyone with a knee injury and mechanical symptoms
- Athletes after a twisting or contact injury
- People with persistent knee pain despite conservative treatment
- Patients being planned for arthroscopy
- Anyone with a suspected ligament or meniscal tear
Conditions it helps detect
How it works
Patient stories
96% recommend“The phlebotomist arrived exactly on time and was gentle. My report came in five hours with a doctor’s note.”
“Booked at night, sample collected next morning. The parameter breakdown is genuinely thorough.”
“Loved the free doctor review — she walked me through my vitamin D and thyroid results clearly.”