Forms of Radiography Imaging

There are five different categories of radiographic imagery, ranging from the traditional X-ray to the modern magnetic resonance imaging (MRI). Other categories are computed tomography (usually called CT scans), ultrasound, and nuclear medicine. Each of the of five has sub-categories for specialized uses.

X-rays

• The X-ray is the oldest form of medical imaging.

  X-rays involve the use of radiation to produce internal images of the body. This is the oldest form of imaging. The system is still used today to diagnose illnesses and injuries. Types of X-rays are myelography, which takes detailed images of the spinal cord and the surrounding area; and fluoroscopy, which produces an X-ray image of internal organs in motion. Both myelography and fluoroscopy, among many other forms of X-ray, are used in conjunction with nuclear medicine.

Ultrasound

• Ultrasound is most commonly used to study fetal development, but is used for other soft tissue concerns as well.

  According to a summary of radiographic medicine on the Froedtert & Medical College of Wisconsin website, ultrasound involves the use of sound waves to produce images of your body; there is no radiation involved. Ultrasound is used to view soft tissues, such as muscles, blood vessels and organs of the body. It can be used in conjunction with magnetic resonance imaging (MRI). Some of the most common uses for ultrasound are the study of obstetrics and gynecological conditions, abdominal conditions, transplanted organs, and the musculoskeletal system. Additionally, ultrasound can be used to diagnose conditions in emergency room cases or in surgical procedures. There are two types of ultrasound: Doppler ultrasound, which views blood flow in the body; and endoscopic ultrasound, which studies the upper and lower gastrointestinal tract, the pancreas, liver and gall bladder.

MRI

• Magnetic Resonance Imaging takes two- and three-dimensional images of the body.

  Magnetic Resonance Imaging (MRI) uses radio-frequency and magnetic waves to produce two- and three-dimensional images of the body. The MRI system scans organs and other soft tissues in the body and is good at detecting cancers. The different types of MRI are: magnetic resonance angiography (MRA), which studies blood vessels and heart conditions; functional MRI (fMRI), which studies changes in brain activity; magnetic resonance spectroscopy (MRS), which focuses on the depth and mass of tumors and speed of growth; diffusion MRI, which studies how water moves in the body; regional cerebral blood volume (RCBV), which follows blood flow in the brain and finds tumors, malfunctions of the central nervous system and other conditions.

CT/PET Scans

• CT scans uses pulses of X-rays to produce cross-sectional images of the body.

  Computed tomography (CT) uses pulses of X-rays to produce thin sectional images and, like the MRI, can produce two- and three-dimensional views. CT scans are used to detect diseases or injuries throughout the body such as cancer, as well as bone, gastrointestinal and lung conditions. Special types of CT are CT neuro-angiography (CTA), which studies brain blood vessels; 64-Slice Lightspeed Volume computed tomography (VCT), which combines X-ray with CT to quickly and accurately detect a wide range of health conditions; and CT angiography, which studies a variety of tissues and organs--especially the heart and blood vessels; the Single Photon Emission Computed Tomography (SPECT) and the the Positron Emission Tomography/Computed Tomography (PET/CT), which both involve the use of nuclear medicine. A PET scan is more sensitive than a CT scan in finding various cancers.

Nuclear Medicine

• Sometimes radioactive agents are given to the patient, then traced with a radiographic device.

  In nuclear medicine, a mildly radioactive agent, such as barium, is injected, inhaled or swallowed by the patient. Then a radiographic device is used to trace the agent, also called a contrast, in the body. This method is often used with X-rays and CT/PET scans.