Magnetic resonance imaging (MRI) uses a large magnet and radio waves to look at organs and structures inside your body. Health care professionals use MRI scans to diagnose a variety of conditions, from torn ligaments to tumors. MRIs are very useful for examining the brain and spinal cord.

During the scan on an open MR, you lie on a table that slides inside an open-environment magnet with two poles. Doing the scan can take from 15-25 minutes, and patient must stay still. The scan is painless. The MRI machine makes some noise during exam.

Before you get a scan, tell your doctor if you:

  • Are pregnant
  • Have pieces of metal in your body. You might have metal in your body if you have a shrapnel or bullet injury or if you are a welder.
  • Have metal or electronic devices in your body, such as a cardiac pacemaker or a metal artificial joint.

Tests and Procedures

MRI is a noninvasive way for your doctor to examine your organs, tissues and skeletal system. It produces high-resolution images that help diagnose a variety of problems.

MRI of the Brain and Spinal Cord

MRI is the most frequently used imaging test of the brain and spinal cord. It’s often performed to help in the diagnoses of:

  • Aneurysms
  • Disorders of the eye and inner ear
  • Multiple sclerosis
  • Spinal cord injuries
  • Stroke
  • Tumors

MR Angiogram (MRA)

MRI can be used to view arteries and veins. Standard MRI can’t see fluid that is moving, such as blood in an artery, and this creates “flow voids” that appear as black holes on the image. Contrast dye (gadolinium) injected into the bloodstream allows, with the help of special software, to see the arteries and the veins. Contrast is also used to enhance viewing tumors and ateriovenous malformatios (AVMs).

MRI of Other Internal Organs

An MRI may be used to check for tumors or other abnormalities of many organs in the body, including, but not limited to, the:

  • Liver
  • Kidneys
  • Spleen
  • Pancreas
  • Uterus
  • Ovaries
  • Prostate
  • Testicles

MRI of Bones and Joints

MRI may be used to help diagnose problems in joints, cases such as:

  • Joint disorders, such as arthritis
  • Joint abnormalities caused by traumatic or repetitive injuries
  • Disk abnormalities in the spine
  • Bone infections
  • Tumors of the bones and soft tissues

MRI of the Breasts

Lately, MRI is being used, in addition to mammography, to detect breast cancer. Particularly in women who have dense breast tissue or those who may be at high risk of the disease.

What are the risks when performing MRI scan?

The presence of metal in the body of a patient may be a safety hazard or affect a portion of the MRI images. Before going through an MRI, tell the technologist if you have any metal or electronic devices in your body. Devices such as:

  • Metallic joint prostheses
  • Artificial heart valves
  • An implantable heart defibrillator
  • A pacemaker
  • Metal clips
  • Cochlear implants
  • A bullet, shrapnel or any other type of metal fragment

You will also need to tell your doctor if you think you’re pregnant. The effects of magnetic fields on fetuses aren’t well understood. Your doctor will recommend choosing an alternative exam or postponing the MRI.

It’s also important to discuss any kidney or liver problems with your doctor and the technologist, because problems with these organs may limit the use of injected contrast agents during your scan.

Before an MRI exam, eat normally and continue to take your usual medications, unless otherwise instructed. You will be asked to change into a gown and to remove:

  • Jewelry
  • Hairpins
  • Eyeglasses
  • Watches
  • Wigs
  • Dentures
  • Hearing aids
  • Underwire bras

Contrast Material

For some MRI exams, a contrast material called gadolinium will need to be injected into a vein in the arm.

While contrast material sometimes improves the MRI images, during pregnancy the exam will typically be performed without contrast material, and a radiologist (a doctor with expertise in medical imaging) will review the images. Contrast material will be used for the exam only if it is necessary to answer your doctor’s question.

Specific Examinations

Knee MRI

What is a Knee MRI?

MRI of the knee provides detailed images of structures within the knee joint, including bones, cartilage, tendons, ligaments, muscles and blood vessels, from many angles.

What are some common uses of the procedure?

In conjunction with conventional x-rays, MRI is usually the best choice for examining the body’s major joints like the knee.

The examination is typically performed to diagnose or evaluate:

  • Knee pain, weakness, swelling or bleeding in the tissues in and around the joint
  • Damaged cartilage, meniscus, ligaments or tendons
  • Sports-related knee injuries, such as sprains, torn ligaments and torn tendons
  • Bone fractures that may not be visible on x-rays and other imaging tests
  • Degenerative joint disorders, such as arthritis
  • Build-up of fluid in the knee joint
  • Infections (such as osteomyelitis)
  • Tumors (primary tumors and metastases) involving bones and joints
  • A feeling that your knee is giving away at the joint
  • Decreased motion of the knee joint
  • Knee cap injury or pain
  • Complications related to implanted surgical devices

Your doctor may also order an MRI to determine if knee arthroscopy or another surgical procedure is needed, and to monitor your progress after knee surgery.

A special form of MRI called an MR arthrogram involves the injection of contrast material into the joint so that the radiologist can get a better look at the relevant structures.

Magnetic Resonance Imaging (MRI) - Spine

What is MRI of the Spine?

An MRI examination of the spine shows the anatomy of the vertebrae that make up the spine, ligaments that hold the vertebrae together, as well as the disks, spinal cord and the spaces between the vertebrae through which nerves pass.

Currently, MRI is the most sensitive imaging test of the spine in routine clinical practice.

What are some common uses of the procedure?

MR imaging is performed to:

  • Assess spinal anatomy and alignment.
  • Detect congenital anomalies of vertebrae or the spinal cord.
  • Detect bone, disc, ligament or spinal cord injury after spine trauma.
  • Assess intervertebral disk disease (degenerated, bulging or herniated) and intervertebral joint disease, both frequent causes of severe lower back pain and sciatica (back pain radiating into lower leg).
  • Explore other possible causes of back pain (compression fracture or bone swelling, such as edema).
  • Assess compression of spinal cord and nerves.
  • Assess inflammation of the spinal cord or nerves.
  • Assess infection involving the spine, disks and spinal contents including spinal cord or its coverings (meninges).
  • Assess tumors that arise from or have spread to the vertebrae, spinal cord, nerves or the surrounding soft tissues.
  • Help plan spinal surgical procedures, such as decompression of a pinched nerve, spinal fusion, or the injection of steroids to relieve spinal pain. Such injections are usually performed under CT guidance.
  • Monitor changes in the spine after an operation, such as scarring or infection.
Magnetic Resonance Imaging (MRI) - Head

What is MRI of the Head?

Currently, MRI is the most sensitive imaging test of the head (particularly the brain) in routine clinical practice.

What are some common uses of the procedure?

MR imaging of the head is performed for a number of abrupt onset or long-standing symptoms. It can help diagnose conditions such as:

  • Brain tumors
  • Stroke
  • Infections
  • Developmental anomalies
  • Hydrocephalus — dilatation of fluid spaces within the brain (ventricles)
  • Causes of epilepsy (seizure)
  • Hemorrhage in selected trauma patients
  • Certain chronic conditions, such as multiple sclerosis
  • Disorders of the eye and inner ear
  • Disorders of pituitary gland
  • Vascular problems, such as an aneurysm (a bubble-like expansion of the vessel), arterial occlusion (blockage) or venous thrombosis (a blood clot within a vein)
Magnetic Resonance Imaging (MRI) - Dynamic Pelvic Floor

What is dynamic pelvic floor MRI?

Dynamic pelvic floor MRI provides detailed pictures of the pelvic floor, a network of muscles that stretches between the pubic bone and spine, and the abdominal organs it supports, including three distinct areas or compartments:

  • The anterior (front) compartment, including the bladder and urethra
  • The middle compartment, including the vagina, cervix and uterus
  • The posterior (rear) compartment which includes the rectum.

During dynamic pelvic floor MRI, images are obtained while the patient is contracting or squeezing the pelvic muscles and while the pelvic muscles are relaxed.

What are some common uses of the procedure?

Physicians use dynamic pelvic floor MRI to:

  • Obtain information about the structure of the pelvic floor and how well the pelvic muscles are working
  • Determine which compartments of the pelvis are damaged and to help identify specific pelvic muscle defects
  • Provide information for surgical and treatment planning
  • Diagnose pelvic floor dysfunction (also called pelvic floor disorders), including:
    • One or more of the pelvic organs falling out of position (a condition called prolapse).
    • The stretching or tearing of the pelvic floor which may cause incontinence, pelvic pain and/or constipation.
MRI of the Musculoskeletal System

What are some common uses of the procedure?

MR imaging is usually the best choice for examining the:

  • Body’s major joints.
  • Spine for back pain.
  • Soft tissues (muscles, tendons and ligaments) and bones of the extremities.

MR imaging is typically performed to diagnose or evaluate:

  • Degenerative joint disorders such as arthritis.
  • Tears of the menisci, ligaments and tendons (knee) or rotator cuff and labrum (shoulder and hip).
  • Fractures (in selected patients).
  • Spinal disk abnormalities (such as a herniated disk).
  • The integrity of the spinal cord after trauma.
  • Sports-related injuries and work-related disorders caused by repeated strain, vibration or forceful impact.
  • Infections (such as osteomyelitis).
  • Tumors (primary tumors and metastases) involving soft tissues around the joints and extremities (such as muscles, bones and joints).
  • Pain, swelling or bleeding in the tissues in and around the joints and extremities.
  • Congenital malformations of the extremities in children and infants.
  • Developmental abnormalities of the extremities in children and infants.
  • Congenital and idiopathic (developing during adolescence) scoliosis prior to surgery.
  • Tethered spinal cord (abnormal stretching in the spinal cord) in infants and children.
Shoulder MRI

What is MRI of the shoulder?

MRI of the shoulder provides detailed images of structures within the shoulder joint, including bones, tendons, muscles and vessels, from any angle.

What are some common uses of the MRI procedure?

MRI is an excellent choice for examining the shoulder joint. MRI gives clear views of rotator cuff tears, injuries to the biceps tendon and damage to the glenoid labrum, the soft fibrous tissue rim that helps stabilize the joint.

MR imaging of the shoulder is typically performed to diagnose or evaluate:

  • Degenerative joint disorders such as arthritis and labral tears
  • Fractures (in selected patients)
  • Rotator cuff disorders, including tears and impingement, which are the major cause of shoulder pain in patients older than 40 years
  • Joint abnormalities due to trauma, such as tears of ligaments and tendons
  • Sports-related injuries and work-related disorders caused by repeated strain, forceful impact or vibration from using certain hand-held tools
  • Infections (such as osteomyelitis)
  • Tumors (primary tumors and metastases) involving bones and joints
  • Pain, swelling or bleeding in the tissues in and around the joint
  • Unexplained shoulder pain that does not get better with treatment
  • Decreased motion of the shoulder joint
  • Progress after shoulder surgery

A special form of MRI called magnetic resonance arthrography involves the injection of a contrast material into the joint so that the radiologist can get a better look at structures within the shoulder.

Magnetic Resonance Cholangiopancreatography (MRCP)

What is Magnetic Resonance Cholangiopancreatography (MRCP)?

Magnetic resonance cholangiopancreatography (MRCP) is a special type of magnetic resonance imaging (MRI) exam that produces detailed images of the hepatobiliary and pancreatic systems, including the liver, gallbladder, bile ducts, pancreas and pancreatic duct.

What are some common uses of the procedure?

Physicians use MRCP to:

  • Examine diseases of the liver, gallbladder, bile ducts, pancreas and pancreatic duct. These may include tumors, stones, inflammation or infection.
  • Evaluate patients with pancreatitis to detect the underlying cause. In patients with pancreatitis, an MRCP may be performed using a medication called Secretin to assess for long term scarring and to determine the amount of healthy pancreatic function and secretions.
  • Help to diagnose unexplained abdominal pain.
  • Provide a less invasive alternative to endoscopic retrograde cholangiopancreatography (ERCP). ERCP is a diagnostic procedure that combines endoscopy, which uses an illuminated optical instrument to examine inside the body, with iodinated contrast injection and x-ray images.
Chest MRI

What Is Chest MRI?

Chest MRI is a safe, noninvasive test. “Noninvasive” means that no surgery is done and no instruments are inserted into your body. This test creates detailed pictures of the structures in your chest, such as your chest wall, heart, and blood vessels.

Chest MRI uses radio waves, magnets, and a computer to create these pictures. The test is used to:

  • Look for tumors in the chest
  • Look at blood vessels, lymph (limf) nodes, and other structures in the chest
  • Help explain the results of other tests, such as a chest x ray or chest computed tomography (to-MOG-rah-fee) scan, also called a chest CT scan.

As part of some chest MRIs, a substance called contrast dye is injected into a vein in your arm. This dye allows the MRI to take more detailed pictures of the structures in your chest.

Chest MRI has few risks. Unlike a CT scan or standard x-ray, MRI doesn’t use radiation or pose any risk of cancer. Rarely, the contrast dye used for some chest MRIs may cause an allergic reaction or worsen kidney function in people who have kidney disease.

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