Other Imaging Techniques Flashcards
(25 cards)
What is the main function of the transducer in ultrasound imaging?
It emits high-frequency sound waves when a voltage is applied
The transducer contains piezoelectric crystals that facilitate this process.
What does acoustic resistance refer to in ultrasound imaging?
The resistance of tissues to sound waves
It determines how much of the sound waves are reflected back to the transducer.
What color does fluid typically show up as in ultrasound imaging?
Black
What color do soft tissues typically show up as in ultrasound imaging?
Grey / white
What are the frequency ranges for high-frequency transducers used in ultrasound?
7.5 or 10 MHz
What are the frequency ranges for low-frequency transducers used in ultrasound?
3.5 or 5 MHz
What is one advantage of using high-frequency transducers?
Good image detail in superficial structures
List three abdominal organs that can be evaluated using ultrasound.
- Liver
- Gall bladder
- Spleen
What happens to sound waves when they hit bone during an ultrasound?
Many of them are bounced back to the transducer.
Name two types of objects that have little resistance to sound waves in ultrasound imaging.
- Gas-filled objects
- Fluid-filled objects
What is the role of the echo in ultrasound imaging?
It is the reflected sound wave that returns to the transducer.
What is ultrasound not good for?
Not good for lungs or bone and large amounts of gas in the GI tract can obscure the abdominal contents.
What does CT stand for?
Computed Tomography
What is CT used for?
Imaging organs, skeletal system, CNS and tumours.
What does hypoechoic mean?
Tissues that produce little echo (appear grey).
What does hyperechoic mean?
Tissues that produce a large echo (appear white).
What does anechoic mean?
Tissues that produce no echo (appear black).
What does CT use?
Ionising radiation
What is scintigraphy?
Nuclear medicine that uses radioactive isotopes to create an image.
What is scintigraphy mainly used for?
Equine medicine to examine bones
Cats to examine thyroid problems
What type of radiation do the radioactive isotopes emit and how is it captured?
Gamma using a gamma camera
What does MRI stand for?
Magnetic Resonance Imaging
Which atoms align with the magnetic field?
Hydrogen atoms
What position should a patient be put in for endoscopy of the upper and lower GI tract?
Left lateral receumbency
