Principles Of Adjuvant Imaging Flashcards
Define the piezo-electric effects
In a ultrasound machine, sound waves are created by vibrations of special crystals in the probe or transducer which alter their shape when a electrical current is applied to them.
B-mode
Brightness mode
In ultrasound, what is it called if there is no echogenicity?
Anechoic (black)
In ultrasound, what is it called when there is low echogenicity?
Hypoechoic
In ultrasound, what is it called when there is high/more echogenicity?
Hyperechoic
What are the two types of transducers
Linear array transducer
Sector scanning transducer
Which transducer is mainly used for rectal investigations in large animals?
Linear array transducer
Which transducer is most suitable for small Aninal work? And why?
Sector scanning transducer- crystals are closer together so only small area of contact is required.
Why might ultrasound be used over x-ray?
Because ultrasound can differentiate between soft tissue and fluid.
It produces a moving picture which is important for cardiac assessments and peristalsis
Doesn’t need GA/sedation always
Advantages of ultrasound
Painless Safe for staff and patient Patients can be conscious Real time image Ultrasound guided biopsies Differentiate between soft tissue and fluid
Disadvantages of ultrasound
Does not penetrate bone and air
Can not be used for bone or lung investigation
Bone reflects the ultrasound and results in black shadows
Difficult to master/ interpretation
Expensive
Clipping needed
Pathology changes can be overlooked
How does skin appear on ultrasound
Smooth and bright
How does fat appear on ultrasound
Can be bright or dark - subcutaneous fat is normally dark
How does muscle appear on ultrasound?
Is dark when viewed In cross section
How does fluid appear on ultrasound?
Is blood, effusions or cyst is appears black but puss/thick fluids can appear bright or dark
