Could you differentiate between CT, MRI, and PET Scans?

Differences between MRI, CT, CAT, and X-ray

These scans are exclusive to Radiography and are unique in their own ways and features.

For elaborate definitions of the MRI CT and X-ray click on the link below;

Disease Diagnosis

Computed Tomography (CT)

The CT as explained in other articles involves the use of high-intensity x-rays which are captured by the detectors from the tube in the opposite direction with the patient in between. These images are now reconstructed by a computer which is connected to the CT machine. The CAT it's just a different name but the same function.

Positron Emission Tomography (PET)

The positron emission tomography is quite a different case. In this situation, a radioactive tracer is injected into the patient. This tracer emits Positrons. When these positrons enter into the body they circulate into every part of the body detecting inflammations, blood vessel damage, and other internal organ diseases or deficiencies. A PET camera is used to monitor the movement of these positrons inside of the body which enables the medical personnel to make diagnosis of the patients condition.

What even makes the PET scan in particular unique is that the PET camera has a 180° detector opposite to each other it can only ignore single photons and images are gotten simultaneously from the 180° detectors.

X-ray

as we all know the x-ray is the basic of radiography diagnosis. it involves the use of electromagnetic radiation which is the X-ray. these x-rays produced in the x-ray tube and then directed through the patient who absorbes the radiation and some pass towards a detector (the cassette) opposite the tube for image production.

The x-ray is quite safer than the computer tomography scan as it uses lesser amount of radiation.

Magnetic Resonance Imaging (MRI)

The MRI is completely different from the abovementioned modalities. it works and relies on the phenomenon of nuclear magnetic resonance. It uses a large, strong magnet which ranges from 1.0 to 1.5 Tesla in open and closed MRI respectively.

this phenomenon enables the MRI machine to scan an object by making use of its protons.

the MRI is reasonably safer than the x-ray, positron emission tomography, and computer tomography.

Conclusion

Each imaging modality has its unique characteristics which it depends on two things: Specificity and Sensitivity. 

The MRI above all is best at combining sensitivity/specificity. Whereas the CT is superior when it comes to sensitivity (Lungs and Bone structures).