An overview of MRI
Magnetic resonance imaging (MRI) is a medical imaging technique that uses a magnetic field and computer-generated radio waves to create detailed images of the organs and tissues in your body. MRI produces high-resolution images that help diagnose a variety of problems, such as brain and spinal cord disorders, heart and blood vessel issues, tumors, and abnormalities in other internal organs. The test is noninvasive, painless, and typically involves lying inside a large, tube-shaped magnet. During the procedure, the internal part of the magnet produces repetitive noises, which may be blocked by earplugs or music. A contrast material, such as gadolinium, may be injected to enhance certain details in the images. The duration of an MRI can vary from 15 minutes to over an hour, depending on the specific exam.
What is MRI used for?
MRI (Magnetic Resonance Imaging) is a medical imaging technique primarily used for noninvasive examination of organs, tissues, and skeletal systems in the body. It creates detailed images of the inside of the body using a magnetic field and computer-generated radio waves. MRI can be used to diagnose a variety of problems, including aneurysms of cerebral vessels, disorders of the eye and inner ear, multiple sclerosis, spinal cord disorders, stroke, tumors, and brain injury from trauma. For the heart and blood vessels, MRI can assess the size and function of the heart's chambers, thickness and movement of the walls of the heart, extent of damage caused by heart attacks or heart disease, structural problems in the aorta, such as aneurysms or dissections, and inflammation or blockages in the blood vessels. MRI can also be used to check for tumors or other abnormalities in various organs, including the liver, kidneys, spleen, pancreas, uterus, ovaries, and prostate. In addition, it can help evaluate joint abnormalities, disk abnormalities in the spine, bone infections, tumors of the bones and soft tissues, and breast tissue. Before undergoing an MRI, it's important to inform your doctor if you have any implanted medical devices, such as pacemakers or cochlear implants, metal clips, pins, screws, plates, stents, or surgical staples, as well as tattoos or permanent makeup. Additionally, if you think you might be pregnant or are breastfeeding, discuss these factors with your doctor.
How to prepare for MRI?
Before an MRI exam, patients are usually advised to eat normally, continue taking their usual medications (unless instructed otherwise), and change into a gown to remove any items that might interfere with the magnetic imaging, such as jewelry, hairpins, eyeglasses, watches, wigs, dentures, hearing aids, underwire bras, and cosmetics that contain metal particles. If a patient has any implanted devices, such as nerve stimulators, pacemakers, metal clips, metal pins, screws, plates, stents, or surgical staples, cochlear implants, bullet or shrapnel, or an intrauterine device, they should inform their doctor and the technologist, as these may also affect the MRI. Patients with tattoos or permanent makeup should consult their doctor to determine if they might impact the MRI. Additionally, pregnant individuals should inform their doctor about their pregnancy, as the effects of magnetic fields on fetuses are not well understood.
How is MRI conducted?
An MRI test is conducted by using a magnetic field and computer-generated radio waves to create detailed images of the organs and tissues in the body. The person being tested lies inside a large, tube-shaped MRI machine. The magnetic field temporarily realigns water molecules in the body, and radio waves cause these aligned atoms to produce faint signals, which are used to create cross-sectional MRI images. The MRI machine can also produce 3D images that can be viewed from different angles.
How are MRI results reported?
The results of an MRI examination are typically reported by a doctor specialized in interpreting MRI images, called a radiologist. This doctor will analyze the images from the scan and provide a report to your doctor, who will then discuss the findings with you.
Understanding the report
MRI results are interpreted by a doctor specially trained to interpret MRIs, known as a radiologist. The radiologist will analyze the images from the scan and report the findings to your doctor. Your doctor will then discuss the important findings and next steps with you based on the interpreted results.
Limitations and Considerations
Limitations of MRI Tests: MRI (Magnetic Resonance Imaging) is a valuable diagnostic tool, but it has certain limitations. Some of these limitations include:
- Claustrophobia: MRI machines are typically large and cylindrical, which can cause anxiety or even panic attacks for people who have claustrophobia. In such cases, sedation or an open MRI may be necessary to ensure a safe and successful examination.
- Metallic Implants: The presence of metallic implants, such as pacemakers, metal clips, or metal pins, can interfere with the quality of the MRI images. In some cases, these implants may even be affected by the strong magnetic field generated during the MRI procedure.
- Contrast Allergy: Some people may have an allergic reaction to the contrast agents used during an MRI. Although rare, such reactions can cause symptoms like hives, itching, or difficulty breathing.
- Limited Flexibility: MRI is a non-invasive technique, but it may not be suitable for patients with extreme obesity or those who cannot lie still for the duration of the examination. In such cases, alternative imaging techniques may be recommended.
- Image Quality Limitations: In some cases, MRI may not provide clear images due to patient movement, excessive body fat, or the presence of metal or other materials that can distort the magnetic field.
- Cost: MRI scans can be expensive, and some insurance plans may not cover the full cost of the procedure. This can make it difficult for patients to access this diagnostic tool. Please consult your doctor or radiology specialist for more information on the specific limitations of MRI in your particular case.