Contrast (gadolinium) is not routinely required for most knee MRIs; standard non-contrast MRI accurately assesses menisci, ligaments, cartilage, and bone marrow. Contrast is reserved for specific situations—suspected infection, tumor, active synovitis/inflammation, or to distinguish scar from recurrent pathology after surgery. The radiologist decides based on the clinical question, patient history, and potential risks (e.g., renal impairment).

A knee MRI scans only the knee(s) specified on the imaging order. Most commonly a unilateral MRI is done for one symptomatic knee, but technicians can image both knees (a bilateral MRI) if requested by the doctor or patient. Bilateral scans take more time, may need a different protocol and could affect scheduling or cost. Confirm with your referrer and the MRI center.

A knee MRI with contrast is generally not painful. The MRI itself is painless, though lying still can be uncomfortable. Contrast needs an IV; you may feel a brief pinch when the needle goes in and a warm flushing or metallic taste during injection. Most people have mild, short-lived discomfort; serious reactions are rare, but mention kidney problems or allergies to your clinician beforehand.

A knee MRI with contrast typically takes about 30–60 minutes from arrival to completion. The actual imaging portion usually lasts 20–45 minutes; contrast injection and extra image sequences add time. Allow an additional 10–15 minutes for IV placement, paperwork and positioning. Total appointment time may be longer if pre-scan checks or post-contrast observation are needed.

MRI with contrast is generally safe for most people. The contrast (gadolinium-based) rarely causes allergic reactions; serious complications like nephrogenic systemic fibrosis are very uncommon except in severe kidney failure, so kidney function is checked first. Small amounts of gadolinium can deposit in tissues, though harm is unclear; newer agents reduce retention. Tell your clinician if pregnant, breastfeeding, have kidney disease, or prior reactions.

Contrast therapy—alternating heat and cold—can reduce knee pain, stiffness, and swelling and improve circulation after activity or for chronic conditions like mild osteoarthritis. Evidence shows short-term symptom relief but is limited for long-term change. Avoid contrast therapy with open wounds, acute infection, uncontrolled diabetes/neuropathy, peripheral vascular disease, or suspected DVT. Start gently and check with a clinician if you have medical conditions.