“What is the difference between a CT scan and an MRI?”
What is the main difference between a CT scan and MRI scan? Please explain.
4 Answers
CT is X-ray based relying on attenuation differences of brain tissues including the gray and white matter and adjacent structures including the skull, facial bones and sinuses. It is fairly easy to detect hemorrhage when it is significant, whereas MRI provides much greater detail and tissue type resolution. It can be more sensitive to the presence of blood in the brain or around the brain. It gives much better anatomic detail and time related changes after events in the brain. It is the closest thing we have to great anatomic detail short of an autopsy.
CT uses radiation while MRI uses a magnetic field and radiofrequency pulses to acquire images. Each one has its benefits over the other.
Unlike CT scans, which use X-rays, MRI scans use powerful magnetic fields and radio frequency pulses to produce detailed pictures of organs, soft tissues, bone and other internal body structures.
CT scans and MRIs are also used for different purposes, although either can be used in some instances. CT scans are extremely helpful in diagnosing serious injuries to the head, chest, abdomen, spine and pelvis, especially fractures. CT scans are also used to pinpoint the size and location of tumors.
MRIs, on the other hand, often do a better job of diagnosing issues in your soft tissues, joints, tendons and ligaments. Doctors frequently order MRIs to scan the brain, spine, neck, breast, abdomen and muscles. MRI is a particularly good tool for evaluating the spine and spinal ligaments.
CT scans and MRIs are also used for different purposes, although either can be used in some instances. CT scans are extremely helpful in diagnosing serious injuries to the head, chest, abdomen, spine and pelvis, especially fractures. CT scans are also used to pinpoint the size and location of tumors.
MRIs, on the other hand, often do a better job of diagnosing issues in your soft tissues, joints, tendons and ligaments. Doctors frequently order MRIs to scan the brain, spine, neck, breast, abdomen and muscles. MRI is a particularly good tool for evaluating the spine and spinal ligaments.
A CT scan uses ionizing radiation to look for differences in attenuation of the tissues to generate tomographic images. For example, bone attenuated more X-rays then fat or muscle and muscle attenuated more X-rays compared with fat. Fat attenuated more X-rays the air.
MRI does not use ionizing radiation and is safer than CT as there is no radiation exposure in the X-ray wavelength. It uses radio waves instead to excite water molecules in tissues. These molecules are undergoing rotational/tumbling motion and absorb radio waves at that frequency and the. Reemit them. Because of this property, MRI is good at seeing the protons in tissues like fat, water, and lack of such protons in bone and air. MRI is therefore more specific for tissue type then CT. Diseased tissue is therefore easier to detect with MRI then CT. However, both have their advantages and disadvantages. For example, CT has better resolution and is better at looking at bone.
Hope this helps,
Brian
MRI does not use ionizing radiation and is safer than CT as there is no radiation exposure in the X-ray wavelength. It uses radio waves instead to excite water molecules in tissues. These molecules are undergoing rotational/tumbling motion and absorb radio waves at that frequency and the. Reemit them. Because of this property, MRI is good at seeing the protons in tissues like fat, water, and lack of such protons in bone and air. MRI is therefore more specific for tissue type then CT. Diseased tissue is therefore easier to detect with MRI then CT. However, both have their advantages and disadvantages. For example, CT has better resolution and is better at looking at bone.
Hope this helps,
Brian
