Emergency Medicine - Intro to Ultrasound Flashcards
effect of incr wavelength
decr resolution, incr penetration
effect of increased frequency
incr resolution, decr penetration
how do you make US image brighter
incr gain
where does probe point
to patients R or head
how does US determine depth of object
amt of time since Echo generated divided by 2 (bc distance = velocity*time)
what probe do you use for IV
linear - high F, max depth 6cm
what probe for abdomen
curvilinear, depth 26cm
colors flow dopler
RED towards, BLUE away
Impedance
Measure of materials tendency to transmit waves. Impacted by elasticity and density of material
Good and poor speculation reflectors
Good: fascial planes, diaphragm
Poor: lung and air filled bowel
Anisotropy
Echogenic when viewed at right angle to US beam, anechoic at other angles
Strong echos look? Absence of echos? Intermediate?
Bright. Black. Gray.