There are several types of MRI scans available. These include Traditional MRI, Functional MRI, Open MRI, and MRA. Each type has its own advantages and disadvantages, and you should ask your doctor about them when you schedule your MRI. These scans are used to diagnose conditions and help doctors make treatment decisions.
Functional MRI
Functional MRI scans can provide detailed pictures of brain activity and help diagnose brain disorders, stroke, epilepsy, and more. This type of scan is noninvasive and can be done in a hospital or an outpatient imaging center. Before your scan, you will need to remove any jewelry or other objects that might interfere with the exam. Also, bring your insurance identification card and any relevant X-rays or previous MRI exams.
Functional MRI scans show the brain with colored areas to show brain regions associated with specific functions. These images are widely used in research, and hundreds of scientific articles are published each month that use functional MRI technology. Many of these articles also appear in the lay press.
Functional MRI scans help define typical and atypical brain connectivity by measuring activity in different parts of the brain. MRI machines use a powerful magnetic field to detect brain activity.
Traditional MRI
Traditional MRI scans use radio waves and magnets to create detailed images of the inside of the body. The patient lies on a flat table and is slid into the MRI machine. The process can take between ten minutes and an hour. Patients can choose to have the scan open or closed, depending on their comfort level. Open MRIs are more comfortable for people with claustrophobia because they are more open and allow for better communication between the patient and technician.
Traditional MRI scans are one of the most common types of MRI scans. This method is not invasive and does not produce harmful radiation. It uses radio waves to re-align hydrogen atoms in the body without causing chemical changes. Each hydrogen atom emits different amounts of energy, which the MRI scanner captures and then converts into a picture.
Open MRI
Open MRI scans have some differences from closed ones. Compared to closed MRIs, these images are less detailed and have poorer quality. For this reason, some doctors choose to use closed MRIs instead. Also, open MRI scans take longer to perform. While some people prefer an open MRI scan, others find it uncomfortable.
Regardless of the type of MRI you choose, there are benefits and drawbacks to each. Patients should discuss their concerns with the ordering physician and technologist before making a decision. For example, an open MRI is better for patients with claustrophobia, who can’t stand being still for long periods of time. For this reason, patients should remove the jewelry and other metallic objects before going in for the scan. Patients should also remove any removable dental work.
Open MRIs are also preferred by patients who are claustrophobic or have high BMI. Unlike closed MRI machines, open MRI scanners offer the highest image quality and are perfect for patients with claustrophobia. In addition, open MRIs allow for more body types.
MRA
A common type of MRI scan is an MRI. This type of scan involves the use of magnetic fields to produce detailed images of the body. During this procedure, the patient must stay very still. The movement will distort the images and can make them unreadable. The patient may experience some pain or discomfort during the procedure. Some people have reported feeling a tingling sensation or hearing noises during the procedure. The procedure can be a bit frightening for some people, so the technologist will often prescribe medications to help the patient.
Some MRI exams require an injection of contrast material into the body. This contrast material helps the radiologist see certain areas of the body more clearly. Gadolinium is one type of contrast material that is used during MRI scans. It is a safer alternative than iodine and is less likely to cause allergic reactions.
RF excitation
MRI scans use a static magnetic field to produce images. MRI scanners take advantage of the high hydrogen content in the body and the magnetic properties of the proton in the hydrogen atom. The spin of the proton induces a small magnetic field, which aligns the protons in the body with the magnetic field. The magnetic field is typically 30 to 60 thousand times stronger than the earth’s magnetic field.
The RF excitation method is different than conventional radio wave transmissions. Conventional radio waves are generated in an alternating electric field and do not have a corresponding magnetic field. The high-powered electromagnetic field generated in an MRI scanner does not produce radio waves, so it is not harmful to the patient or to other parts of the scanner.
RF excitation is another common type of MRI scan. The pulses from the RF are tuned to a certain range of the hydrogen protons’ precessing frequencies. This causes the proton to move out of phase and into phase with other hydrogen protons. The duration between the pulse and the peak of the signal produced by the coil is measured in milliseconds.
MRA of the extremities
MRI scans of the extremities can identify fractures and other problems that a traditional X-ray cannot detect. These scans are conducted using a special scanner that scans one limb at a time. Patients can sit comfortably during the procedure. These scans are painless and safe, and they do not involve any radiation.
Although these scans may be controversial, there are some indications for them. They may be used to monitor the progression of arthritis. However, the American College of Rheumatology (ACR) recommends that X-rays be used for this purpose. They can also be used to monitor the progression of disease in patients with facioscapulohumeral muscular dystrophy. MRI has also become a standard tool for orthopedic diagnosis and is used to detect injuries such as meniscal tears and cruciate ligament tears.
Patients who require an MRI scan of the extremities should understand the risks involved. These procedures can take a long time. Young children may require sedation to help them remain still.
MRA of the brain
There are several different types of MRI scans for the brain, each aimed at a different purpose. One type is called functional MRI and is used to study the brain’s activity. It helps doctors determine if a patient is at risk for brain injury or surgery and can also provide information about the functioning of the brain. These scans are also often used to diagnose dementia or Alzheimer’s disease.
Functional MRI involves performing a series of small tasks to assess the functions of certain brain areas. This type of scan is much more detailed than the others, which are limited to examining brain structure. It is also a better choice for detecting brain abnormalities that are not visible to the naked eye. In addition, MRI scans can detect abnormalities that might be obscured by bone or other soft tissues.
An MRI is an invasive procedure that takes about 30 to 50 minutes. If you’re having a brain MRI, you should be prepared for a few uncomfortable moments. The procedure involves a loud noise, and it is not uncommon for a person to experience claustrophobia during the process. Some people may even experience a twitching sensation during the scan.
MRA of the neck
MRA scans are used to look at blood vessels. They are non-invasive and painless. The patient lies head-first on a scanning table while a coil is placed around the neck. The body is then moved into a magnet. During the procedure, the patient is given sedatives or is awake.
MR scans of the neck can help doctors diagnose a variety of disorders. They are particularly useful for screening people for atherosclerosis. This disease involves the buildup of fat on the walls of the medium and large arteries. If these arteries become blocked, the patient is at risk for a stroke.
Because of time constraints, MRA scans of the neck are often limited to the cervical carotid artery and the internal carotid artery. Full studies of intracranial vessels, however, require the patient to be positioned three times in a head and neck coil. A full scan can take more than an hour. For this reason, MRA scans of the neck should be reserved for patients suspected of having concurrent pathology.
MRA of the chest
MRA scans are used to detect a variety of diseases and conditions of the chest. These scans are not always necessary. For instance, a patient may not need a full MRI if their chest x-rays are normal. For example, a patient with suspected aneurysms could have a pulmonary artery mass. A chest MRA would allow a physician to see this mass at a higher resolution.
Although MRA is not a substitute for a CT or MRI, it provides additional imaging capabilities for patients with suspected aneurysms. However, it is not clear if MRA has a clinical role in screening patients with subacute symptoms. Additionally, its low diagnostic yield does not make it a useful tool for routine workups of non-specific or non-focal symptoms.
MRI and MRA scans of the chest are useful for detecting strokes and other heart problems. These scans provide doctors with high-resolution images of infarcted areas and can even be added to an MRI if it is necessary. However, MRI is generally not required for transient ischemic attacks (TIAs), as they do not usually display any vascular abnormalities.
