There are a number of different types of medical imaging equipment to assist in the diagnosis of illness and injury. X-ray and computed tomography (CT) scans, for example, are useful for assessing broken bones and looking for certain types of cancer. Nuclear imaging also can detect cancer, as well as infections and injury. Other common types of medical imaging equipment include ultrasound and magnetic resonance imaging (MRI).
One of the most common types of medical imaging equipment is the X-ray scanner. X-ray imaging works by firing high-energy electromagnetic waves at the body. These are absorbed by dense structures in the body, such as bone, but pass through the less dense areas. X-ray imaging allows a doctor to assess the body's bony structures, which is particularly useful when checking for bone fractures. X-rays also can be effective at checking for certain types of cancers, such as breast cancer.
CT scans are similar to X-rays but, instead of a single image, a computer is used to take images from different angles. The patient lies on a table and the scanner moves around the body while sending out X-rays from different sides of the body. This allows the doctor to assess parts of the body that aren’t usually accessible with a regular X-ray image.
For assessing certain types of cancer and infections, nuclear scanning is often used. A radioactive substance, which can be detected by specially designed cameras, is injected into the body. The scanner then detects where the substance is, resulting in an image. This type of imaging is considered safe, because the dosage of radioactive material is very small.
Another common form of medical imaging equipment is ultrasound. Ultrasound is higher frequency than a human’s hearing range and bounces off a substance based on its density. This allows ultrasound medical imaging equipment to detect the difference between liquid and solid areas of a body, resulting in an image of internal structure. The benefits of ultrasound equipment include that the technology is small enough to carry around and ultrasound is generally harmless.
MRI works differently from X-rays, because it doesn’t use high-energy electromagnetic waves. Instead, an MRI machine can detect changes in the magnetic spin of atoms in the body. A strong magnetic field is applied to the body while a computer reads the data from the machine and forms a detailed image. MRI machines are capable of providing high-resolution images but can’t be used on people with any form of metal implant.