Low Field Machines:
What is a low field MRI machine?
There are various specific types of MRI scans that may be ordered by your doctor. Each have their own unique purpose or reason for being named.
Some of the more frequently ordered MRI types include:
A Head MRI can look at the brain for tumors, an aneurysm, bleeding in the brain, nerve injury, and other problems, such as damage caused by a stroke. A head MRI can also find problems of the eyes and optic nerves, and the ears and auditory nerves.
A Chest MRI can look at the heart, the heart valves, and coronary blood vessels. It can show if the heart or lungs are damaged. An MRI of the chest may also be used to look for breast or lung cancer. These can also be ordered after a mammogram exam has been given to see areas of the breast tissue in more detail.
MRA or magnetic resonance angiography is a type of magnetic resonance image (MRI) scan. MRI scans are used to look at blood vessels, and the flow of blood through them is called magnetic resonance angiography (MRA). MRA scans can find problems of the arteries and veins, such as an aneurysm, a blocked blood vessel, or the torn lining of a blood vessel (dissection). Sometimes contrast material is used to see the blood vessels more clearly. Like an MRI, magnetic resonance angiograms (MRA) use a magnetic field and pulses of radio wave energy to make pictures of blood vessels inside the body.
Abdomen and pelvis MRI scans can find problems in the organs and structures in the belly, such as the liver, gallbladder, pancreas, kidneys, and bladder. They can be used to find tumors, bleeding, infection, and blockage. In women, MRI scans can look at the uterus and ovaries. In men, they can look at the prostate.
Bone and joint MRIs can check for problems such as arthritis, problems with the temporomandibular joint, bone marrow problems, bone tumors, cartilage problems, torn ligaments or tendons, or infection. These MRI scans may also be used to tell if a bone is broken when X-ray results are not clear. MRI scans are done more commonly than other tests to check for some bone and joint problems.
A Spine MRI can check the discs and nerves of the spine for conditions such as spinal stenosis, disc bulges, and spinal tumors.
Remember, your radiologist and your doctor can only work with the quality of what he is given. If you have an order for an MRI, look for a facility that has a quality machine as well as a quality staff. And remember a good radiologist with skill and experience is as important to find as a good doctor.
OTHER FREQUENTLY ASKED QUESTIONS:
- What are MRI scans?
- Why would someone need or get a MRI scan?
- What are the different types of MRI scans?
- What is an MRI experience like?
- What are the costs of a MRI scan?
- What are the risks of a MRI scan?
- How are MRIs different than MRA scans?
- How are MRIs different than x-rays or CT scans?
Low Field Scans:
What is a low field MRI scan?
Any quality medical facility that does MRI exams should be able to tell you what specific machine they would use for your doctor's order and even provide a description of it.
Most patient's first question is, 'How open is it?' However, this might not be the question they should be asking. Many times a doctor or imaging facility will recommend a machine that doesn't have the biggest opening or space around you. Why?
There are many reasons but image quality rises to the immediate top. Think about it - Your doctor, your radiologist, and even you want the best, clearest imaging possible to be able to 'see' just what's going on inside of you. This might mean using a machine that's better suited for getting the highest quality of image possible rather than the highest amount of comfort possible.
The types of MRI scanners will often be differentiated by their magnetic field strength (telsa) or by construction or orientation, such as open, closed or standing.
High-Field MRI Scanners
High-Field MRI scanners are usually closed or tube or tunnel like due to their use of stronger magnets ranging from at least 1.5T up to 3.0T. A 1.5T MRI scanner is useful because it provides a really great quality image. It can also boast fast scan times and the ability to evaluate how certain structures in the body others may not. The 3.0T MRI scanner, which is double in strength, becomes great for visualizing very fine detail such the vessels of the brain or heart. There is also an ultra-high field scanner which has a strength of 7.0T. It is not widely available and is typically used for research.
Low-Field MRI Scanners
Low-Field MRI scanners are typically identified as open MRI scanners and have a magnet range of 0.23T-0.3T. These scanners are useful for people who are claustrophobic or unable to have a closed MRI scan due to weight or size. Low-field scanners are typically open on the sides rather than having the magnets completely surrounding the patient. Low-field MRI scanners have decreased image quality and require a longer scan times compared to high-field MRI scanners, but they provide an alternative for those who otherwise might not be able to have an MRI scan.
Traditional Closed MRI Scans
A closed MRI scanner or machine is a large tube that a patient lays in. Fortunately, this type of scanner almost always produces images that are of the highest quality. However, the small tube that a patient must lay in can cause a patient who is claustrophobic to panic. Patient comfort in these machines is also sometimes a problem if they are very heavy or large. The MRI machine requires the patient to lie very still. A patients who is moving around can make scanning almost impossible but that can be the case for almost any MRI type. Don't be suprised if your doctor recommends this type of scanner. He's looking to get the best images possible. And aren't you?
Open MRI Scans
The open MRI was developed in an effort to allow claustrophobic patients more comfort and to allow some obese or larger patients to be scanned. The technology in the magnets with these machines have come very close to matching those seen in a closed MRI. These open MRIs still require a patient to lie down, but do not completely enclose the patient. And that can mean a lot of anxiety relief. You can read more about open MRIs here.
Standing or Sitting MRI Scans
The latest MRI experience is now being tauted from advanced MRI machines that allow patients to stand or sit while having their exams done. While these machines help with patient comfort, they currently don’t provide the high levels of image quality that the closed or even some open scans provide. In the future these machines will hopefully improve in many aspects which will make them much more useful. Right now they are only useful in very specific circumstances. And, as you may find when looking for one, are very rare.
Remember, your radiologist and your doctor can only work with the quality of what he is given. Call around. Believe it or not, it may be worth traveling an extra few miles away to have your MRI done in a less open MRI machine that it is in the wide open one down the street. Talk with your doctor or imaging facility before your next MRI and discuss what is right for your situation.