MRI ஸ்கேன் பரிசோதனை தெரிந்து கொள்வோம் - MRI Scan Procedure

MRI Scan - Uses and Procedure

MRI scan uses a strong magnetic field and radio waves to generate images of parts of 

the body that can't be seen as well with X-rays, CT scans or ultrasound.

The human body is mostly water. Water molecules (H2O) contain hydrogen nuclei (protons), 

which become aligned in a magnetic field. An MRI scanner applies a very strong magnetic field 

(about 0.2 to 3 teslas, or roughly a thousand times the strength of a typical fridge magnet), 

which aligns the proton "spins."

The scanner also produces a radio frequency current that creates a varying magnetic field. 

The protons absorb the energy from the magnetic field and flip their spins. When the field is turned off, the protons gradually return to their normal spin, a process called precession. 

The return process produces a radio signal that can be measured by receivers 

in the scanner and made into an image.Protons in different body tissues return to their normal spins at different rates, so the scanner can distinguish among various types of tissue. The scanner settings 

can be adjusted to produce contrasts between different body tissues. Additional magnetic fields 

are used to produce 3-dimensional images that may be viewed from different angles. 

CT ஸ்கேன் பரிசோதனை தெரிந்து கொள்வோம் - CT or CAT Scan

CT Scan or CAT Scan

A CT scan or a computed tomography scan is a large machine with the ability 

to take x-rays which is aimed at a patient then quickly rotated fully around 

the body of the patient which produces a tomographic image or slices of within the body. 

These images are taken through the whole body which then uses 

these photos to create a slice image. These CT scans are more beneficial 

as they can be used through the whole body and can locate structures and abnormalities. 

Where the X-rays are emitted in the cylinder is called the emitter and 

180° to the emitter is the receiver in which the x-ray image is imprinted on. 

The patient is laid out on a bed which moves through the cylindrical the scanner 

then circles the patient then the x-rays are received at many 

different points as the emitter and receiver are rotated around the patient. 

Each time the bed moves the patient the scanner circles them again. 

The x-rays are analysed by a computer and then the computer constructs an image in slices of the patient.