Medical Imaging Flashcards
Define Radiology
A branch of medicine concerned with the use of radiant energy such as x-rays or radioactive material
What are the different types of medical imaging
Conventional X-ray - use of X-ray radiation
Computed Tomography (CT) - uses a series of X-rays to create cross sectioned images
Nuclear Medicine - Use of radioactive drugs and a scanner to show how organs are functioning
Magnetic resonance Imaging (MRI) - Uses magnetic fields and radio waves
Ultrasound Imaging - High-frequency sound waves
What is mammography?
Specific X-rays for imaging breasts
what are the colours of the 5 density principles
Black = air/gas Dark grey = Fat Light grey = soft tissue (organs and muscle ect) Bone = off white Contrast material/metal = bright white
What are the disadvantages and advantages of X-rays
Exposure to harmful radiation, poor imaging of soft tissue, limited number of x-rays given due to the radiation
Good at imaging bones, readily available, quick imaging
What is tomography?
Imaging technique that produces single tissue planes
What are the disadvantages and advantages of CT imaging
High dose radiation and not good at imaging soft tissues such as brain.
Fast, readily available and good at imaging bony structures, abdomen and lungs
What is Scintigraphy?
Use of gamma radiation to form images following injection of radiopharmaceuticals
What are the disadvantages and advantages of Scintigraphy Nuclear Medicine
High dose radiation and not good at differentiating against different pathologies.
Good functional information and good at localisation of pathologies.
What does MRI scanners use?
A power magnetic feild and radiofrequency pulses.
What are the disadvantages and advantages of MRI
Potentially dangerous strong magnet, not good for imaging bones, expensive, long scanning duration and need for anaesthetics in difficult/young patients
Gold standard of imaging, no radiation, good localisation and differentiation of pathologies and excellent at imaging soft tissues such as brain.
What are the disadvantages and advantages of Ultrasounds
Highly dependant on operator, structures surrounded by bone such as brain do not give good images. Not good at scanning structures obscured by gas
Ultrasound is safe and there is no use of ionising radiation. The equipment needed is portable, compact and relatively inexpensive.
