Test 2: lecture 10 Flashcards
what transducer gives you a rectangle field
rectilinear array- used for superficial structures such as tendons
what kind of transducer is good for abdominal ultrasound
curvilinear array
what transducer is used for echos?
annular array (target pattern)
allows to go through ribs
gain
turning up the brightness
general gain- brightness of overall image
Time gain compensation (TGC) - depth dependent brigthness
Internal structure of organs
– homogeneous, coarse, mottled…
echostructure
echogenicity
brightness of a tissue
hyperechoic
hypoechoic
isoechioic
anechoic - black at all gain (fluid)
anechoic
black at all gains- fluid (urine in bladder)
A1 is anechoic
A1 is hypoechoic to A2
B1 is isoechoic to B2
C1 is hyperechoic to C2
reverberation artifact
when ultrasound is repeatedly reflected between two highly reflective surfaces (pocket of sound bouncing back and forth)
(air filled intestine)
ultrasound not good to look at normal lung
what kind of artifact
reverberation artifact
air in intestine causes lines below that are obscuring everything below the bubble
comet tail artifact -little bubbles of gas cause artifact
acoustic shadowing
structure absorbs waves (stone, bones, foreign body) everything deeper to that object is darker
edge shadowing
when wave hits border of curve structure with very different density than what is around it, wave will suddenly change position → darkness
gallbladder
distal enchancement
used to find fluid filled structures
deeper portion is stronger because it went through fluid that did not echo the sound → the tissue deeper to a fluid filled structure is lighter then just tissue area
This is a longitudinal section of the left adrenal gland in a dog. The caudal pole of the gland is outlined by the calipers. Compared to the area ‘1’, the adrenal gland is:
hypoechoic
This is an ultrasound image of the stomach of a dog that has a gastric tumor: the wall is thickened (between calipers) and hypoechoic. Distal to this thickened wall, the type of artifact outlined by the arrows are:
Comet tail artifacts, a particular type of reverberation artifact
This is an image of the common bile duct (CBD) in a cat with jaundice. The jaundice was caused by gallstones blocking the CBD. It shows:
Gall‐stones stuck in the CBD associated with acoustic shadowing
This is a longitudinal section of an intestinal loop in a dog with diarrhea (between arrow‐heads). A long structures bordered by two hyperechoic lines is seen in the lumen of that intestinal loop. This was a parasitic worm causing the symptoms. What else is contained within the lumen of that intestinal loop?
Some sort of fluid
(fluid is dark/black)
