Many people are not experts on diagnostic imaging terms and can often be confused when their physician suggests one scan over another. MRI’s and CT Scans are two common types of diagnostic imaging scans but many people struggle with differentiating the two.
How are they different?
A CT (also known as a CAT Scan or Computerized Axial Tomography) is usually used for bone injuries, lung imaging, chest imaging, and cancer detection. They are often used for emergency procedures because they are fast (that’s why they always ask for CTs on Grey’s Anatomy). On the other hand, a MRI (or Magnetic Resonance Imaging) is used for soft tissue scanning (ligaments, tendons, spinal cord, brain tumors, etc.). It can take up to a half hour to complete and is usually more expensive than CT scans. MRI’s also do not use any radiation during the imaging process.
Here's how they work.
MRI machines use a magnet to send radio waves to read the energy produced by the water molecules as they re-align themselves after each pulse of radio waves. That data actually creates the 2D image of the axis of the body. Since there’s essentially no water in bones, they don’t have an image, which is where the black space comes in.
CT machines use x-ray waves, which rotate around the patient, sending waves towards the “x-ray detector” on the other side of the patient. The beam goes through the patient, and the detector receives the image, measuring the strength of the beam about 1000 times per second. The comparisons of the beams create the image.
Both scans haves their purpose in diagnostic imaging world. While they both present various pros and cons against the other, a doctor can be suggest what type of scan is best for you. If you have any questions or concerns regarding MRI’s, please feel free to contact us at Clovis Open MRI.