Medical imaging techniques are critical in modern medicine for diagnosing a variety of conditions. X-rays, for example, are often used to detect broken bones and some types of cancer. Computed tomography (CT), in which multiple X-ray images are taken, can provide more detailed images than a standard X-ray. Magnetic resonance imaging (MRI) scans are one of the more expensive types of imaging system but can provide highly detailed images of organs and structures inside the body. Other forms of medical imaging techniques include ultrasound and nuclear imaging.
X-ray scans are one of the most frequently used types of medical imaging techniques. To take an X-ray image, high-energy electromagnetic waves, which can go through soft tissue but are absorbed by bone, are aimed at the body and then detected from the other side. Areas through which no X-rays pass are known as shadows and are shown as bone on the image. Computed tomography is a more advanced technique in which multiple images are taken from different angles and then combined to form a more detailed picture.
MRI scans also are commonly used in many hospitals around the world. Instead of using high-energy radiation, MRI scans detect the change in magnetic spin of particles in the body. This allows for a detailed picture of organs and other internal structures. While MRIs often produce some of the best diagnostic images, the process is relatively slow and costs a lot of money. MRI scans are often difficult to perform on children, who may not want to stay still, and they cannot be used on people with metal implants.
Ultrasound is one of the best examples of medical imaging techniques that are quick and simple to perform. An ultrasound machine is often portable and can be used to obtain an internal image within minutes. The detail of images produced by ultrasound is relatively poor, however, so it isn’t suitable for situations in which detailed images are required.
Nuclear medical imaging techniques are used to obtain detailed images of organs and structures in the body. It also can be effective at detecting changes in a system, such as how blood is flowing through a certain area. To take a nuclear image, a small amount of radioactive dye is injected or inhaled. This flows around the body and, because of its radioactive emissions, can be detected by a scanner. The patient lies still why the scanner takes multiple images to build up a detailed view of what’s happening inside the body.