Radiation In Medicine Flashcards
What three devices use radiation in medicine?
CAT (CT) Scan
Ultrasound scanner
Endoscope
How do CAT scans work?
It uses x-rays to scan body
What are the advantages of CAT scans?
- detailed images
- 3D images can be built up on a computer from sectional scans
What are the disadvantages of a CAT scan?
- expensive equipment
- relatively high radiation dose
How does ultrasound work?
High-frequency sound waves are reflected by features inside a patient’s body
What is an advantage of ultrasound?
-very low risk - allows a real-time image to be viewed
What are the disadvantages of ultrasound?
None - widely used in prenatal monitoring
How does an endoscope work?
Uses fibre optics to provide live view of the internal structures in a patient
What is an advantage of using an endoscope?
- provided direct, real-time view of internal body tissue
- allows keyhole surgery, without the need for major surgery
What is an disadvantage of using an endoscope?
-cannot see through tissues
What is intensity?
Intensity of radiation is the amount of energy arriving per second over an area of 1m squared
How is intensity and distance related?
Intensity decreases with distance because radiation is spread over an increasing area
What is the equation for intensity and distance?
P = I x A
Intensity (in W/m squared) = Power (W) x area (m squared)
