ultrasound Flashcards
what can ultrasound be used for?
to allow a doctor to see inside a patient without surgery
name uses of ultrasound for diagnostic purposes
to check the condition of the foetus
investigate heart and liver problems
to look for tumours in the body
to measure the speed of blood flow in vessels when a blockage of a vein or artery is suspectd
how does a doctor deal with kidney stones using ultrasound?
a high powered ultrasound beam is directed at the kidney stones
the ultrasound energy breaks the stones down into smaller pieces
then the pieces are excreted form the body
why is ultrasound preferred to x-rays?
- able to produce images of soft tissue
- doesn’t damage living cells
why can ultrasound be used for body scans?
when ultrasound is reflected from different interfaces in the body, the depth of each structure is calculated by using the formula distance=speed x time, knowing the speed of ultrasound for different tissue types and the time for the echo to return
the proportion of ultrasound reflected at each interface depends on the densities of each of the adjoining tissues and the speed of sound in the adjoining tissues
if the tissues are very different most of the ultrasound is reflected, leaving very little to penetrate further into the body
the information gained is used to produce an image of the part of the body scanned
what is ultrasound?
sound which is a higher frequency than humans can hear
how does ultrasound travel?
as a pressure wave containing compressions and rarefactions
what are compressions?
regions of higher pressure and rarefactions are regions of low pressure
name 2 features of longitudinal waves?
they cant travel through a vacuum
the higher the frequency or pitch, the smaller the wavelength
