Medical Imaging Primer

• CT
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• MRI
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• PET
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• Radiation Therapy (RT)
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• Ultrasound
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• X-Ray

• Computed Tomography (CT)

  Computed Tomography (CT), also commonly referred to as a CAT scan, is a medical imaging method that combines multiple X-ray images taken from different angles to produce detailed cross-sectional pictures of areas inside the body. The resulting images provide more information than regular X-rays, and allow doctors to look at individual slices within the 3-D images.

  CT is often used to evaluate:

  • Organs in the pelvis, chest and abdomen
  • Colon health (CT colongraphy)
  • Presence of tumors
  • Pulmonary embolism (CT angiography)
  • Abdominal aortic aneurysms (CT angiography)
  • Spinal injuries

  

  Courtesy of General Electric

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• Magnetic Resonance Imaging (MRI)

  Magnetic Resonance Imaging (MRI) is a medical imaging technology that uses radio waves and a magnetic field to create detailed images of organs and tissues. MRI has proven to be highly effective in diagnosing a number of conditions by showing the difference between normal and diseased soft tissues of the body.

  MRI is often used to evaluate:

  • Blood vessels
  • Breasts
  • Organs in the pelvis, chest and abdomen (heart, liver, kidney, spleen)

  

  Courtesy of General Electric

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• Positron Emission Tomography (PET)

  Positron Emission Tomography (PET) is a type of nuclear medicine that provides physicians with information about how tissues and organs are functioning. PET, often used in combination with CT imaging, uses a scanner and a small amount of radiopharmaceuticals which is injected into a patient’s vein to assist in making detailed, computerized pictures of areas inside the body.

  PET is often used to evaluate:

  • Neurological diseases such as Alzheimer’s and Multiple Sclerosis
  • Cancer
  • Heart disease

  

  Courtesy of Siemens

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• Radiation Therapy (RT)

  Radiation therapy (RT) is used to treat a wide range of cancers by delivering highly targeted radiation to cancerous cells, destroying their ability to grow and divide while leaving healthy cells intact. Generally, RT is delivered through beams emitted from a machine outside the body or through brachytherapy, which involves placing the radiation source directly inside or near the site of the cancerous cells. Cancer patients may be treated with both radiation therapy and chemotherapy to limit the need for more exploratory surgery.

  

  Courtesy of Philips

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• Ultrasound

  Diagnostic ultrasound, also known as medical sonography or ultrasonography, uses high frequency sound waves to create images of the inside of the body. The ultrasound machine sends sound waves into the body and is able to convert the returning sound echoes into a picture. Ultrasound technology can also produce audible sounds of blood flow, allowing medical professionals to use both sounds and visuals to assess a patient’s health.

  Ultrasound is often used to evaluate:

  • Pregnancy
  • Abnormalities in the heart and blood vessels
  • Organs in the pelvis and abdomen
  • Symptoms of pain, swelling and infection

  

  Courtesy of Siemens

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• X-Ray

  X-ray technology is the oldest and most commonly used form of medical imaging. X-rays use ionizing radiation to produce images of a person’s internal structure by sending X-ray beams through the body, which are absorbed in different amounts depending on the density of the material.

  X-ray images are typically used to evaluate:

  • Broken bones
  • Cavities
  • Swallowed objects
  • Lungs
  • Blood vessels
  • Breast (mammography)

  

  Courtesy of General Electric

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