Type of MRI machine
Magnetic resonance imaging, also called MRI, is a technique used in medicine to scan (scanning) organ in the body in detail.
This technique involves the use of an MRI machine. MRI machines typically have a long-range 1,5 - 2,5 meters. Scanning is done with part or all of a patient's body is positioned (placed) in the machine.
There are two types of MRI machines are closed and open engine. Both types of machines are basically using the same technology.
In a closed MRI machine, the patient is in an MRI machine or tube is scanned. Generally, the tube closed MRI machine has a width of about 60 cm.
Open MRI machines tend to be not as good as closed. However, open MRI machine will be an option for patients whose phobia of enclosed spaces or suffer from claustrophobia.
As the name suggests, the design of an open MRI machine does not make the patient fully closed. Some models even allow patients to undergo a scan while sitting or standing.
How it Works The MRI machine
MRI machine has a magnetic coil that generates a strong magnetic field is used to scan the patient. Magnetic field will cause the hydrogen atoms in the human body to position themselves along the magnetic field.
Ideal hydrogen atoms used in scanning because the human body is dominated water consisting of two hydrogen atoms and one oxygen atom.
The machine then issued a series of radio frequency (RF) which causes only the excited hydrogen atoms.
When a hydrogen atom is excited trying to get back into position along the magnetic field generated machine, the atoms release excess energy taken from the RF wave.
Machine then detects and records the energy release. In some cases, patients may be asked to swallow or get an injection of contrast agent, usually gadolidium, before undergoing an MRI scan.
MRI contrast agents makes the picture has better resolution so as to facilitate analysis.
Photos MRI
You've probably seen the MRI images displayed on a computer screen. Such images are not generated directly from the MRI machine. Actual machine only recording the energy as a function of time.
Images on a computer screen is an interpretation of the reading function of time into a function of frequency.
Simply put, the MRI machine record mathematical data about the movement of atoms (hydrogen) and process the data with a mathematical process called Fourier transformation.
Fourier transformation was made a mathematical data can be displayed visually on a computer screen.