What Is Radiologic Technology Medical Imaging?

Medicine radically changed in the twentieth century with the onset of radiographic imaging. When masses or other disease processes that could be seen were suspected, exploratory surgery was the method used for verification. Sometimes, surgery was successful at finding the cause of a patient's symptoms. At other times, surgery produced no results. The development of radiography allowed physicians to look inside the body without the risks of surgery.

Discovery

• Roentgen rays, or x-rays, were first discovered by Wilhelm Conrad Roentgen in 1895. He discovered the behavior of rays emitted from a tube with positive and negative electrodes. He took a radiograph of his wife's hand that same year. In 1896, independent of Roentgen's discovery, Henri Becquerel discovered that uranium gave off rays that could pass through certain substances and expose photographic film. It was Becquerel's discovery that interested Marie Curie who, along with her husband, Pierre Curie, discovered polonium and radium, which are both more radioactive than uranium.

Medical History

• The medical community had already begun using x-rays for diagnostic imaging of bones by 1900. Many were also realizing that x-rays had adverse health effects when overexposure led to burns. In the mid-1900s, man-made gamma ray sources replaced radium. These new sources allowed for greater penetration and resolution. Today's medical imaging is replacing film with computers and the penetration and resolution continues to improve.

X-Ray

• X-rays are best known as those black and white images of bones. X-ray is commonly used to diagnose bone injuries, but it serves other purposes as well. Chest x-rays detect pneumonia and sometimes soft tissue nodules are seen. Contrast is used to assess the kidneys, ureters and bladder. Barium is a form of contrast that can be swallowed and used to assess the digestive tract using fluoroscopy, a method of x-ray that allows real-time imaging. Fluoroscopy can also be used for vascular imaging and procedures.

Computed Tomography

• Computed tomography is a radiographic imaging modality that allows the use of x-rays to acquire images of multiple sections of the body. CT images are much more detailed and clearer than regular radiographs. CT can be used to construct three-dimensional images of body structures, including the heart and blood vessels. Air can be used to open the colon to perform a virtual colonoscopy. As with x-ray, contrast is used to assess vascular and digestive structures.

Nuclear Medicine

• Nuclear medicine takes radiographic technology a step further. Unlike x-rays and computed tomography scans, nuclear medicine assesses the function of organs. Radioactive substances are injected into the patient and a special camera is used to detect the radiation given off by these substances. Examples of nuclear medicine studies include gallbladder and thyroid function tests.