MRI Scan Guide: What to Expect, How to Prepare & Safety Information

MRI (Magnetic Resonance Imaging) is a painless diagnostic imaging test that uses a powerful magnetic field and radio waves to create detailed images of your organs, tissues, and bones. Unlike X-rays and CT scans, MRI uses no ionizing radiation, making it one of the safest imaging technologies available.

Think of an MRI like this: Your body is full of hydrogen atoms (mostly in water). When placed in a strong magnetic field, these atoms align. Radio waves then knock them out of alignment. When the radio waves stop, the atoms return to alignment and release signals. The MRI computer converts these signals into incredibly detailed images.

What makes MRI special:

• No radiation—completely safe in that regard
• Amazing soft tissue detail—shows organs, muscles, ligaments, tendons, and nerves with incredible clarity
• Multiplanar—can image from any direction without moving you
• Safe for repeated use—no cumulative radiation concerns
• Functional imaging—can show how organs work, not just what they look like

Your healthcare provider may recommend an MRI to:

Diagnose Conditions

Brain and Nervous System:

• Brain tumors and their extent
• Multiple sclerosis plaques
• Stroke damage and recovery
• Aneurysms and vascular malformations
• Brain infections
• Herniated discs and spinal stenosis
• Nerve compression syndromes

Joints and Musculoskeletal:

• Sports injuries (ACL, meniscus, rotator cuff)
• Tendon and ligament tears
• Cartilage damage
• Unexplained joint pain
• Bone tumors and infections
• Muscle injuries

Organs and Soft Tissues:

• Liver tumors and characterization
• Pancreatic problems
• Kidney tumors
• Reproductive organ abnormalities
• Prostate cancer staging
• Breast cancer imaging and staging

Guide Medical Procedures

• Planning surgery before operations
• Guiding biopsies of tumors or abnormalities
• Planning radiation therapy for cancer treatment
• Assessing treatment response to see if therapies are working

Monitor Disease Progression

• Multiple sclerosis activity and progression
• Tumor response to chemotherapy or radiation
• Degenerative conditions like arthritis
• Healing progress after injuries or surgeries

When MRI is Preferred Over CT

• Soft tissue evaluation: MRI shows much more detail than CT for brain, spinal cord, and joints
• No radiation desired: For children, pregnant women, or patients requiring frequent imaging
• Contrast allergies: MRI contrast (gadolinium) is different from CT contrast and has fewer allergic reactions
• Implant safety: Some patients with implants cannot have CT (if unsafe with MRI, though many implants are also unsafe with CT)

Understanding the process can significantly reduce anxiety and help you feel prepared.

Before Your MRI

Arrival and Screening:

• Arrive 30 minutes early for check-in and safety screening
• Bring your ID, insurance card, and referral form
• Complete a detailed safety questionnaire about metal in your body
• You may need to change into a hospital gown
• Remove all metal objects: jewelry, watches, hairpins, hearing aids, glasses

Safety Screening is Critical: The powerful magnet can move metal objects and interfere with implanted devices. You must tell the technologist if you have:

• Pacemakers or implanted defibrillators (generally NOT safe with MRI)
• Aneurysm clips or coils
• Artificial heart valves
• Cochlear implants
• Neurostimulators
• Metal fragments in your eyes (especially from welding or metalwork)
• Artificial joints or limb implants
• Intrauterine devices (IUDs)
• Tattoos (some inks contain metal)
• Any other implanted medical devices

If you have an implant:

• Bring implant information cards with you
• The radiologist will review safety information before your scan
• Some implants are safe, some are not, some are conditionally safe
• Never conceal implant information—safety depends on honesty

IV Placement (if contrast will be used):

• A nurse or technologist will start an IV in your arm or hand
• The IV may sting briefly but is generally not too uncomfortable
• The IV stays in place throughout the scan for contrast injection if needed

During Your MRI

Positioning:

• You'll lie on a narrow table that slides into the MRI machine
• The technologist will help you get into the correct position
• Pillows, cushions, and straps may help you stay in position
• Coils (special devices) may be placed around the body part being imaged
• You must stay as still as possible throughout the scan
• The technologist will leave the room but can see and hear you at all times

Inside the Scanner:

• The MRI machine looks like a long tube or tunnel
• You will be mostly or fully enclosed during the scan
• The tube is well-lit and ventilated
• You can see your surroundings through mirrors in some machines
• You can communicate with the technologist via an intercom system
• You may be given headphones to listen to music or audiobooks

The Scanning Process:

• The table will slide into the magnet
• The scanner will make loud banging, tapping, and clicking noises during imaging
• You'll wear ear protection (earplugs, headphones, or both) to protect your hearing
• Scans can take 30-90 minutes depending on what's being imaged
• Several sequences (individual scans) may be performed
• You may need to hold your breath briefly for some sequences (typically 10-20 seconds)
• The technologist will tell you when each sequence will start and how long it will take
• You can communicate with the technologist at any time through the intercom

What You'll Feel:

• The scan itself is completely painless
• The machine makes loud noises but ear protection helps
• You may feel warm in the area being scanned (normal, but tell the technologist if it's uncomfortable)
• The table may move slightly between sequences
• If contrast is used, you may feel a cool sensation at the IV site when it's injected
• Some people feel claustrophobic or anxious—this is normal and common

After Your MRI

Immediate Post-Scan:

• The table will slide out of the scanner
• The technologist will help you off the table
• The IV will be removed (if used)
• You can return to normal activities immediately
• No sedation effects (unless you received sedation for anxiety)
• You can drive yourself home (unless you received sedation)

If You Received Contrast:

• Drink extra water to help flush the contrast from your body
• The contrast is eliminated through urine over the next 24 hours
• Call your doctor if you notice any unusual symptoms
• Allergic reactions to gadolinium contrast are rare but possible

Getting Your Results:

• A radiologist will carefully analyze your MRI images
• A detailed report will be sent to your referring doctor
• Most results are available within 24-72 hours
• Complex cases may take longer if special consultation is needed
• Your referring doctor will contact you to discuss findings

Proper preparation ensures the best possible images and a smooth experience.

General Preparation

What to Wear:

• Wear comfortable, loose-fitting clothing without metal (zippers, buttons, snaps, rivets)
• Sweatpants and a t-shirt are ideal
• Remove all jewelry and piercings
• Remove hearing aids, glasses, and removable dental work
• Avoid wearing makeup (some contains metallic particles)
• Don't use hairspray or gel (metal cans, possible metal particles)

What to Bring:

• Photo ID and insurance card
• Doctor's referral or prescription for the MRI
• List of current medications and supplements
• Information about any implants (bring implant cards if you have them)
• Previous imaging results (if requested by your doctor)
• Music on your phone or MP3 player (if you want to listen during the scan)

Medications:

• Take your regular medications unless told otherwise
• Bring a list of your medications to share with the imaging staff
• If you have anxiety, ask if you should take an anti-anxiety medication before the scan

Special Preparation for Contrast MRI

With Gadolinium Contrast:

• No special preparation is typically needed for most contrast MRIs
• You may be asked to fast for 2-4 hours before the scan (but this is less common than for CT)
• Tell your doctor if you have:
  • Kidney problems or kidney disease
  • Previous allergic reactions to gadolinium contrast
  • Any allergies, especially to contrast materials
• Blood tests may be needed beforehand to check kidney function if you have risk factors

Special Considerations

Pregnancy and Breastfeeding:

• Tell your doctor if you're pregnant or might be pregnant
• MRI is generally considered safe after the first trimester when necessary
• MRI uses no radiation, making it safer than CT or X-ray during pregnancy
• Gadolinium contrast crosses the placenta but is generally avoided during pregnancy
• If breastfeeding, gadolinium passes into breast milk in tiny amounts
  • You can continue breastfeeding, or
  • Some mothers choose to "pump and dump" for 24 hours after contrast

Children:

• Pediatric MRIs use the same equipment but may involve sedation
• Children may need sedation to stay still for the scan
• Child life specialists help prepare children for the scan
• Practice lying still at home before the appointment
• Bring comfort items (stuffed animal, blanket) if allowed

Claustrophobia and Anxiety:

• Tell your doctor BEFORE your appointment if you're anxious or claustrophobic
• Sedation options:
  • Oral sedation (take a pill before the scan)
  • IV sedation (administered at the imaging center)
  • You'll need someone else to drive you home if you receive sedation
• Open MRI options may be available (less claustrophobic but images may be less detailed)
• Communication: You can talk to the technologist throughout the scan
• Visualization techniques: Practice relaxation and mindfulness before your appointment
• Bring a support person: Some facilities allow someone to stay in the room with you

Mobility Issues:

• Call ahead if you need assistance
• The imaging center has equipment to help transfer patients
• Some facilities have tables that accommodate higher weight limits
• MRI tables typically support up to 350-500 pounds depending on the machine

Getting your results can feel stressful. Here's what to expect and what the terminology means.

Who Reads Your MRI?

A radiologist—a medical doctor specially trained in interpreting medical images—will carefully analyze your MRI images and prepare a detailed report for your referring doctor. Some radiologists specialize in specific body parts (neuroradiologists for brain/spine, musculoskeletal radiologists for joints).

When Will You Get Results?

Turnaround times vary:

• Emergency scans: Within hours
• Routine scans: Typically 24-72 hours
• Complex cases: Sometimes 3-5 days if special consultation or second opinions are needed

Your referring doctor will contact you to discuss the results and next steps.

Understanding Your Radiology Report

Your report will contain several sections:

Patient Information:

• Your name, age, and the date of the exam
• The reason for the scan (what your doctor is looking for)
• The type of MRI performed

Technique Description:

• Technical details about how the scan was performed
• What sequences were used (T1, T2, FLAIR, etc.)
• Whether contrast was used
• The specific body parts imaged

Findings:

• Detailed description of what the radiologist sees
• Measurements of any abnormalities found
• Comparison to prior scans (if available)
• Description of normal anatomy and any deviations

Impression/Conclusion:

• The radiologist's interpretation of the findings
• A summary of what's most important
• Recommendations for follow-up if needed

Common Terminology in MRI Reports

Reassuring Terms:

• Normal/Unremarkable: No abnormalities found—this is good news!
• No acute abnormalities: No new or concerning findings
• Stable: No change from previous scans (often good)
• Benign: Non-cancerous, not concerning
• Physiologic: Normal findings for your age and body
• Post-surgical changes: Expected changes from previous surgery

Terms That May Need Follow-up:

• Inconclusive: Unable to make a definitive diagnosis—more tests may be needed
• Indeterminate: Unclear findings—additional imaging or monitoring may be recommended
• Recommend follow-up: The radiologist suggests repeat imaging to monitor something over time
• Clinical correlation recommended: Findings need to be considered along with your symptoms and exam
• Recommend clinical correlation: The radiologist wants your doctor to examine you in light of the imaging findings

Terms That May Indicate Concern:

• New/enlarging: Something has appeared or grown since prior scans
• Suspicious: Findings that could represent serious conditions like cancer
• Pathologic: Abnormal findings that may indicate disease
• Enhancing: Areas that "light up" with contrast (can be normal or abnormal)
• Edema: Swelling or fluid (can indicate injury, infection, or tumor)
• Mass: A growth (may be benign or malignant)
• Lesion: An area of abnormal tissue (may be benign or malignant)

Specific MRI Terminology:

T1 and T2:

• T1-weighted: Shows anatomy well, fat appears bright, fluid appears dark
• T2-weighted: Shows pathology well, fluid appears bright
• Radiologists use both to characterize abnormalities

Enhancement:

• Areas that become brighter after contrast injection
• Can indicate tumors, inflammation, infection, or normal tissue
• The pattern of enhancement helps radiologists make diagnoses

Signal Intensity:

• Hyperintense: Bright on the image
• Hypointense: Dark on the image
• Isointense: Same brightness as surrounding tissue

MRI is one of the safest imaging technologies when proper safety protocols are followed. However, the powerful magnet creates unique safety considerations.

The Magnet: What Makes MRI Special

The MRI magnet is ALWAYS on:

• The magnet is never "turned off" (in most clinical scanners)
• Its magnetic field extends beyond the machine
• Metal objects can become dangerous projectiles near the scanner
• The magnetic field can affect implanted medical devices

How strong is the magnet?

• Most clinical MRI scanners use 1.5 Tesla or 3.0 Tesla magnets
• For comparison, a refrigerator magnet is about 0.01 Tesla
• Earth's magnetic field is about 0.00005 Tesla
• MRI magnets are 30,000 to 60,000 times stronger than Earth's magnetic field

Metal and MRI: The Safety Concerns

Projectile Risk:

• Unsecured metal objects can become dangerous projectiles
• Oxygen tanks, wheelchairs, and other equipment have been pulled into MRI magnets
• This is why the MRI suite is strictly controlled

Implants and Medical Devices:

• Some implants are NOT safe in MRI (pacemakers, certain aneurysm clips)
• Some implants are conditionally safe (certain artificial joints, some types of coils)
• Some implants require special precautions (certain heart valves, some neurostimulators)
• ALWAYS tell the technologist about ANY implants in your body

Tattoos and Permanent Makeup:

• Some tattoo inks contain metallic particles
• These inks can heat up during MRI
• This is rare but can cause discomfort or burns
• Tell the technologist if you have tattoos, especially in the area being scanned

Gadolinium Contrast Safety

Some MRI scans use gadolinium-based contrast agents to enhance image clarity.

Benefits of gadolinium:

• Shows blood vessel detail
• Highlights tumors and inflammation
• Helps characterize abnormalities
• Generally safer than iodine-based CT contrast

Risks and considerations:

• Allergic reactions are rare (much less common than with CT contrast)
• Nephrogenic systemic fibrosis (NSF) is a rare but serious condition in patients with severe kidney disease
• Gadolinium deposition in the brain and body has been observed, though clinical significance is unclear
• Modern gadolinium agents are much safer than older formulations

Safety measures:

• Kidney function is checked before contrast in at-risk patients
• Safer types of gadolinium are used for patients with kidney problems
• Premedication may be given if you have a known allergy

Other MRI Safety Considerations

Pregnancy:

• MRI is generally considered safe after the first trimester when necessary
• No radiation exposure
• Gadolinium contrast is generally avoided during pregnancy
• Always tell your doctor if you're pregnant or might be pregnant

Claustrophobia:

• Significant concern for many patients
• Open MRI options are available (though images may be less detailed)
• Sedation can help (you'll need a driver)
• Communication with the technologist can ease anxiety

Hearing Protection:

• MRI scanners are LOUD (110-120 dB, like a jackhammer)
• Ear protection is mandatory to prevent temporary or permanent hearing damage
• Earplugs, headphones, or both are provided
• You can often listen to music during the scan

Different MRI techniques are used for different purposes and body parts.

By Body Part

MRI of the Brain:

• Diagnose tumors, strokes, multiple sclerosis
• Evaluate headaches, seizures, memory problems
• Assess traumatic brain injury
• Plan brain surgeries

MRI of the Spine:

• Diagnose herniated discs, spinal stenosis
• Evaluate back pain and sciatica
• Assess spinal cord compression
• Plan spinal surgeries

MRI of Joints (Knee, Shoulder, Hip, etc.):

• Diagnose ligament and tendon tears (ACL, meniscus, rotator cuff)
• Evaluate cartilage damage
• Find causes of unexplained joint pain
• Assess sports injuries

MRI of Abdomen/Pelvis:

• Evaluate liver, kidney, pancreatic tumors
• Characterize ovarian and uterine abnormalities
• Assess prostate cancer
• Find causes of abdominal pain

MRI of Breast:

• Screen high-risk patients for breast cancer
• Evaluate extent of known breast cancer
• Assess response to chemotherapy
• Problem-solve when mammography is inconclusive

MRI of Blood Vessels (MRA):

• Evaluate aneurysms and vascular malformations
• Assess blood vessel blockages
• Plan vascular surgeries
• Follow up after vascular procedures

By Special Technique

Functional MRI (fMRI):

• Shows brain activity by detecting blood flow changes
• Used to map brain function before surgery
• Research applications in neuroscience and psychology
• Requires special equipment and expertise

Diffusion MRI:

• Measures water molecule movement in tissues
• Can detect stroke within minutes of symptom onset
• Helps characterize tumors
• Essential for early stroke diagnosis

Magnetic Resonance Angiography (MRA):

• Visualizes blood vessels without invasive procedures
• Can detect aneurysms, blockages, and vessel malformations
• Often uses contrast to enhance vessel visibility

Magnetic Resonance Venography (MRV):

• Visualizes veins specifically
• Diagnoses blood clots (DVT) in veins
• Evaluates venous malformations

Spectroscopy:

• Analyzes chemical composition of tissues
• Helps distinguish tumor types
• Research applications
• Limited clinical availability

If you're claustrophobic or anxious about MRI, you may have an option for an open MRI.

Traditional (Closed) MRI

What it is:

• The conventional MRI design—a long tube or tunnel
• You lie on a table that slides into the tube
• You are mostly or fully enclosed during the scan

Advantages:

• Higher field strength (usually 1.5T or 3.0T)
• Better image quality and detail
• Faster scanning
• More widely available
• Can do any type of MRI (all sequences and techniques)

Disadvantages:

• More claustrophobic
• Tighter space can be uncomfortable for larger patients
• Weight limits are typically lower (350-500 lbs)

Open MRI

What it is:

• MRI scanners with open sides or a more open design
• You are less enclosed during the scan
• Several designs exist: completely open, open-bore, wide-bore

Advantages:

• Less claustrophobic and more comfortable for anxious patients
• Can accommodate larger patients
• Easier for children (parents can sometimes stay nearby)
• Better for patients with mobility limitations

Disadvantages:

• Lower field strength (often 0.25T to 1.0T)
• Lower image quality and detail
• Longer scan times
• May not be able to do all types of MRI sequences
• Less widely available

Making the Choice

Closed MRI is better when:

• Image quality and detail are the top priority
• You need a specialized MRI technique (like fMRI or spectroscopy)
• You're not claustrophobic
• You don't exceed the weight limit

Open MRI is better when:

• You're severely claustrophobic and can't tolerate closed MRI
• You're a larger patient who doesn't fit in a closed scanner
• Image quality is less critical than comfort
• You can't have sedation for medical reasons

Discuss both options with your referring doctor to determine which is best for your situation.

Does an MRI hurt?

No, MRI scans are completely painless. You may experience discomfort from lying still on a hard table or from the IV insertion if contrast is used.

How long does an MRI take?

Most MRI scans take 30-90 minutes. The time varies depending on what body part is being imaged and how many sequences are needed.

Will I be claustrophobic?

Many people feel claustrophobic during MRI. If this is a concern, ask about open MRI or sedation options before your appointment.

Can I drive after an MRI?

Yes, unless you received sedation. Most people drive themselves home after MRI scans.

Can I eat and drink before my MRI?

For most MRIs without sedation, you can eat and drink normally. If you're having sedation or abdominal imaging, you may need to fast. Follow your specific preparation instructions.

What if I have metal in my body?

Tell your doctor and the imaging center BEFORE your appointment. Some metal is safe, some is not, and some depends on the specific implant. Safety screening is critical.

Is MRI safe during pregnancy?

MRI is generally considered safe after the first trimester when necessary because it uses no radiation. However, gadolinium contrast is generally avoided during pregnancy. Always tell your doctor if you're pregnant.

Why is MRI so loud?

The loud banging and tapping noises are caused by the magnetic field gradients turning on and off rapidly during scanning. Ear protection is mandatory.

What if I can't lie still for that long?

Tell your doctor before scheduling. Options include sedation (you'll need a driver), shorter protocols, or sometimes open MRI where you may be more comfortable.

Can someone be in the room with me?

Maybe, depending on the facility's policies and whether your companion passes safety screening (no metal implants, etc.). Ask about this when scheduling.

What happens if I need to use the bathroom during the scan?

Try to use the bathroom before your scan. If it's an emergency, the scan can be paused (though this may mean starting sequences over).

Why did the technologist keep talking to me?

They need to give you instructions about breathing and staying still, and they want to make sure you're okay during the scan.

Before your appointment:

• Ask questions if anything is unclear
• Follow preparation instructions carefully
• Arrange for childcare if needed
• Practice lying still at home
• Wear comfortable clothing without metal

During your appointment:

• Communicate openly with the technologist about any discomfort
• Stay as still as possible during scanning sequences
• Take slow, deep breaths to stay relaxed
• Close your eyes if seeing the confined space bothers you
• Listen to music or audiobooks to distract yourself
• Remember that you can talk to the technologist at any time

After your appointment:

• Follow up with your doctor to get your results
• Keep a copy of your report for your records
• Drink extra water if you received contrast

• MRI scans are painless, non-invasive and use no radiation
• Proper preparation—especially removing metal and disclosing implants—ensures safety and the best results
• MRI takes 30-90 minutes and requires you to lie very still
• The machine is loud but ear protection is provided
• Claustrophobia is common—solutions include open MRI, sedation, and communication with the technologist
• Gadolinium contrast enhances images but carries small risks, especially for patients with kidney disease
• Safety screening is critical—always disclose implants and metal in your body

Understanding MRI:

• MRI vs CT Scan: Key Differences
• Open MRI vs Traditional MRI
• MRI Claustrophobia: Coping Strategies

MRI Preparation:

• MRI Preparation Checklist
• Questions to Ask Before Your MRI

Understanding Results:

• Understanding Your MRI Report
• Common MRI Findings Explained

Preparing for Your MRI?

Download our free MRI Preparation Checklist with everything you need to know and do before, during, and after your MRI scan for a smooth, stress-free experience.

Download Free MRI Prep Checklist

Disclaimer: This guide is for educational purposes only and does not replace professional medical advice. Always consult with your healthcare provider about which imaging tests are appropriate for your specific situation.