Medical Imaging

Question 1

What are X-Rays?

Answer 1

• discovered by Wilhelm Rontgen
• he found that a ray could pass though flesh and an outline of bones
• by the 1900s they were used to detect various injuries and diseases
• x-rays are high energy electromagnetic radiation with a short wavelength that can penetrate solids and ionizing gases

soft tissues = gray
hard tissues = light shadow

Question 2

What is a Computed Tomography (CT)?

Answer 2

• imaging that is done by sections
• non-invasive imaging technique
• uses computers to analyze cross-sectional x-rays
• invented in 1970s
• x-rays pass through the body and are absorbed or reflected at different levels

Question 3

What is Magnetic Resonance Imaging (MRI)?

Answer 3

• non-invasive imaging tehnique
• based on experiement whee matter was exposed to magnetic fields and radio waves were found to emit radio signals
• used clinically starting in the 1980s
• no radiation exposure
• expensive
• uncomfortable and loud
• you are enclosed in a loud metal tube

Question 4

Positron Emission Tomography (PET)

Answer 4

• uses radiopharmaceuticals (substances that emit short-lived radiation)
• introduced in 1961 and 15 years later combined with radiopharmaceuticals
• illustrate physiologic activity of targeted organ(s)