An MRI scan, also known as magnetic resonance imaging, is a painless procedure that generates clear pictures of the internal structures and organs of the body. To provide extremely precise images, MRI requires a magnetic field, radio waves, and a computer for image processing. MRI is the diagnostic procedure preferred for individuals who require frequent scanning for diagnostic evaluation or treatment, specifically of their brain, since it does not involve X-rays or any other radiation technique.
An open MRI scanner typically has two horizontal magnets placed above and beneath you with a lot of room for you to lay down between them. As a result, there is space on two sides, which reduces the feeling of claustrophobia that several individuals have while using closed-bore MRI scanners. Open MRI devices, however, don’t produce the same clarity of pictures as closed MRI.
The opening or tunnel in the centre of closed MRI scanners, where you would position yourself to obtain pictures, is formed by a circular arrangement of the magnetic field. In close-bore MRI scans, the head-to-ceiling distance is considerably limited. Some people may feel anxious and uncomfortable due to the limited distance; however, these MRI scans produce the best-quality pictures. Speak with your doctor if you have a fear of enclosed spaces or are anxious about your MRI scan. Your doctor will discuss the possibilities for sedatives (drugs that relax you) or anaesthesia if it is required.
An injectable contrast substance may be used during several MRI tests. An element called gadolinium is present in the contrast medium. The quality of the pictures is improved once this chemical is in your body because it changes the magnetic characteristics of neighbouring water molecules. This increases the diagnostic pictures’ specificity and sensitivity.
The following become more visible with the use of a contrast medium:
- Tumours
- Arterial system
- Swelling of any region inside the body
- Infections in any region of the body
- Blood supply to the region/organ of the body being examined
An intravenous line (IV) will be placed into a vein inside your arm or hand if your MRI test necessitates the use of a contrast medium. The contrast medium will be injected through this IV. Contrast mediums are free of risk medications. They can lead to mild to moderate side effects, but severe side effects are extremely rare.
Uses of MRI scan
Magnetic resonance imaging is a tool used by medical professionals to aid in the diagnosis and/or follow-up of various medical conditions. Additionally, there are many MRI scan types depending on the part of your body that your doctor wants to examine.
Several illnesses can be evaluated and diagnosed using spinal cord and brain MRI tests, such as:
- Brain tumours
- A brain aneurysm (a delicate part of an artery inside or near your brain)
- Spinal tumours
- Brain injuries induced by trauma
- Spinal injuries caused by trauma
- Multiple sclerosis (damages the central nervous system’s nerve cells)
- Inflammation or compression of the nerves and spinal cord
- Spinal cord disorders
- Stroke
- Spine anatomy and posture.
Heart (cardiac) MRIs are used by doctors for several purposes, including:
- To detect the diseases of the heart, such as infections, tumours, and inflammatory diseases
- To determine the dimension of blood vessels and circulation of blood via your major blood vessels, surrounding tissues, the morphology and functionality of your heart’s chambers, valves, and other components
- To determine the consequences of coronary artery disease (CAD), including reduced flow of blood to the muscles of the heart and scarring inside your heart muscle following a cardiac arrest
- To determine the heart’s as well as blood vessels’ function and structure in adults and children with congenital heart defects.
Body MRIs may be used to analyse structures and identify several diseases, such as: - Tumours in the pelvis, abdomen, or chest
- Disorders of the liver, such as cirrhosis, as well as complications with the bile ducts and pancreas
- Inflammation of the intestinal tract, including ulcerative colitis and Crohn’s disease
- Blood vessel abnormalities and vascular inflammation (vasculitis)
- An evolving foetus inside a female’s womb.
Joints and bones MRI tests can be used to determine: - Inflammation of the bones (osteomyelitis)
- Bone cancers
- Problems with your spine’s discs
- Joint problems due to injuries.
Breast MRI scans–These are sometimes combined with mammography by medical professionals to diagnose breast cancer, specifically in those with thick tissue in the breast or individuals who are potentially at a high risk.
Preparations required for MRI scan
Strong magnets and radio wave signals used by the MRI scans can cause certain metallic items in your body to heat up and even shift. Health and safety hazards could arise as a result of this. Additionally, this interaction between radio waves and devices could result in the malfunctioning of several implanted electronic medical gadgets.
Before the MRI scan, your doctor has to be informed if you have any metal-containing items or implants inside your body. It might be necessary to make additional preparations and follow special instructions for some implanted gadgets (for example, pacemakers). Other metal objects (screws used to fix fractures) don’t need special instructions, although they might necessitate the use of X-ray to determine their precise location before your MRI test.
If you have any of the following implants inside your body, make sure to let your doctor and the MRI technician know.
- Defibrillator or heart pacemaker
- Deep brain stimulators, bladder stimulators, vagus nerve stimulators, neurostimulators, spine stimulators, and implanted electrodes or wires
- Prosthetic joints made of metal
- Implants inside the ears, such as Cochlear implants
- Implanted medication pumps, especially those that deliver painkillers, narcotics, or medicines for spasticity (Abnormally elevated muscular tone or rigidity) treatment
- Programmable cerebrospinal shunts
- Coils and clips for aneurysms
- Filters for blood clots.
The patients undergoing an MRI are forbidden from wearing during their MRI test. MRI consultation should be scheduled on the same day when a medicine patch or other medical devices are to be replaced.
These devices may include:
- Insulin pump
- Medicinal patches (for example, hormonal patches, vitamin supplement patches, and nicotine patches)
- Insulin pump
- Continuous glucose monitoring (CGM) device.
Additionally, let your physician know if you:
- Are pregnant
- Are unable to spend 30 to 60 minutes lying on your back
- Suffer from claustrophobia or a phobia of small or enclosed environments.
Remove any jewellery and other items before the MRI test or keep them at home because they could disrupt the MRI machine’s magnetic field, result in burns, or become dangerous projectiles. Metal and electrical objects are not permitted in the examination room. These objects or items include jewellery, wristwatches, pins, metal hair accessories, underwire bras, metal zippers, body piercings, dentures, glasses, pens, electronic watches, cell phones, tracking devices, credit cards, and hearing aids.
What happens after an MRI Scan?
No recovery time is required if you aren’t administered a sedative before the MRI scan. You can return home and carry on with your everyday activities. However, if you receive a sedative before the MRI test, you must recover from their side effects before you are allowed to leave for home.
You may require a ride home from a family member or a friend. After your MRI test, if you experience any discomfort, redness, or inflammation at the location of your IV, you should let your doctor know since this could be a sign of infection or a different type of reaction. After the MRI test, your doctor will give you additional instructions depending on your condition.
Safety of MRI Scan
When necessary, safety precautions are taken, an MRI scan is usually safe and offers nearly no threat to the individual. The intense magnetic field produced by MRI machines doesn’t harm you, but it could interfere with implanted medical equipment or alter the MRI pictures. If your MRI involves the administration of a contrast medium, there is slight chance that you will experience an allergic response.
Typically, these responses are minor and manageable with medicine. A medical professional will be available to provide immediate care if you experience an allergic reaction. Due to the unknown risks to the unborn child, medical professionals typically avoid doing MRI tests that include the administration of contrast medium on pregnant patients unless it is mandatory.
Benefits of MRI scans
• MRI is a safe imaging method.
• Radiation-free imaging is possible with MRI, which is a non-invasive imaging method.
• In some cases, the pictures of the body’s soft-tissue organs including the liver and many others obtained using MRI are more effective in detecting disorders than those acquired through other imaging techniques. Because of this, the MRI test is a very useful tool for timely diagnosis and treatment.
• MRI is effective in the diagnosis of several diseases, such as heart disease, cancer, and vascular disease as well as the anomalies of the muscles and bones.
• MRI can reveal problems that conventional imaging techniques might miss due to bone obstruction.
• MRI helps medical professionals to perform a safe, contrast-free examination of the biliary tract.
• The gadolinium contrast agent used in MRI tests is less likely to induce an allergic reaction than the iodine-based contrast agents used in X-rays and CT scans.
• MRI offers a safe alternative to X-ray, CT scan, and angiography for detecting heart and blood artery disorders.
Risks of MRI Scan
- When technicians follow the necessary safety precautions, the MRI test rarely causes a threat to the patient.
- While sedating an individual, there can be a slight possibility of overdose. To reduce this danger, the doctor will always keep an eye on your pulse and heart rate.
- The powerful magnetic field does not harm the patient. However, it might result in picture alteration or dysfunction of implanted medical gadgets.
- A known side effect of gadolinium contrast infusion is nephrogenic systemic fibrosis. With the application of more recent gadolinium contrast mediums, such side effects are rarely seen. In people with severe kidney disease, it commonly develops. Before deciding whether to administer a contrast medium, your physician will thoroughly inspect the condition of your kidneys.
- If your exam involves the application of a contrast medium, there may be a very small chance of an allergic response. These responses are typically moderate and go away on their own frequently. You can contact a physician immediately if you experience an allergic response. Research has indicated that the extremely minute levels of gadolinium might remain inside the body after several MRI tests.
Limitations of MRI Scan
You can find it challenging to remain motionless throughout the MRI test if you feel confused and anxious or are experiencing severe pain. However, if you don’t remain still and don’t follow breathing directions while the technician takes the photographs there is a possibility that the technician may not be able to capture high-quality pictures.
Certain MRI equipment may not be able to fit a significantly obese individual because the scanners have weight restrictions.
It can be challenging to get clear images when there are implants or other metal items present inside the patient’s body.
Low-quality magnetic resonance (MR) pictures can also result from the ascites liquid that is present inside the abdomen or pelvis in considerable amounts.
