SonoSim
High impedance produces a bright image - Answer-Strong reflection of sound waves = high amplitude =
bright/echogenic image
Low impedance produces a dark image - Answer-Paucity of returning sound waves = low amplitude =
dark/anechoic image
High-frequency transducer - Answer-a. Good for superficial structures
b. Increasing frequency improves resolution, but at the expense of penetration
Lower-frequency transducer - Answer-Good for structures deep within the body
Unit of measurement of transducer - Answer-megahertz (MHz)
Transducer indicator - Answer-a. Imaging convention to direct cephalad or to patient's anatomic right
side
b. Transverse orientation (anatomic right direction)
c. Longitudinal orientation (cephalad direction)
Attenuation- artifact - Answer-Progressive weakening of sound as it travels through the body
, High attenuation (clean shadowing) - Answer-i. When sound encounters high-attenuating tissue, echoes
are weakened posteriorly, and an acoustic shadow results
ii. Occurs deep to highly-attenuating tissue
Ex. Gallstones
Low attenuation (increased through-transmission) - Answer-i. Sound waves can travel through fluid-
filled organs with little attenuation
ii. When sound encounters low-attenuating tissue, echoes are enhanced posteriorly
iii. Bladder can be used as an acoustic window
1. Ex. Sound can travel through fluid in the urinary bladder with little attenuation
2. Structures posterior to bladder become hyperechoic
iv. Enhancement- strengthening of echoes distal to a weakly-attenuating structure
Reverberation (multiple equidistantly spaced reflections) - Answer-a. Multiple reflections between
transducer and object being imaged, or within a structure
b. Caused by a strongly reflective and smooth surface
c. Appears as recurrent, bright, horizontal echoes at equidistant intervals
Comet-tail artifact- aka B-line artifact or lung rocket - Answer-a. Reverberation artifact
Mirror image artifact - Answer-a. Sound resonates between pleural-air interface and liver multiple times
with delayed signal transmission
b. US machine misinterprets the extra time as something further afield and thus plots more liver tissue
c. Mirror-image artifact present = no fluid in the chest
i.Ex. Very helpful in diagnosing hemothorax and pleural effusion
Ultrasound waves - Answer-a. B-mode (greyscale) imaging depicts internal tissue structure
High impedance produces a bright image - Answer-Strong reflection of sound waves = high amplitude =
bright/echogenic image
Low impedance produces a dark image - Answer-Paucity of returning sound waves = low amplitude =
dark/anechoic image
High-frequency transducer - Answer-a. Good for superficial structures
b. Increasing frequency improves resolution, but at the expense of penetration
Lower-frequency transducer - Answer-Good for structures deep within the body
Unit of measurement of transducer - Answer-megahertz (MHz)
Transducer indicator - Answer-a. Imaging convention to direct cephalad or to patient's anatomic right
side
b. Transverse orientation (anatomic right direction)
c. Longitudinal orientation (cephalad direction)
Attenuation- artifact - Answer-Progressive weakening of sound as it travels through the body
, High attenuation (clean shadowing) - Answer-i. When sound encounters high-attenuating tissue, echoes
are weakened posteriorly, and an acoustic shadow results
ii. Occurs deep to highly-attenuating tissue
Ex. Gallstones
Low attenuation (increased through-transmission) - Answer-i. Sound waves can travel through fluid-
filled organs with little attenuation
ii. When sound encounters low-attenuating tissue, echoes are enhanced posteriorly
iii. Bladder can be used as an acoustic window
1. Ex. Sound can travel through fluid in the urinary bladder with little attenuation
2. Structures posterior to bladder become hyperechoic
iv. Enhancement- strengthening of echoes distal to a weakly-attenuating structure
Reverberation (multiple equidistantly spaced reflections) - Answer-a. Multiple reflections between
transducer and object being imaged, or within a structure
b. Caused by a strongly reflective and smooth surface
c. Appears as recurrent, bright, horizontal echoes at equidistant intervals
Comet-tail artifact- aka B-line artifact or lung rocket - Answer-a. Reverberation artifact
Mirror image artifact - Answer-a. Sound resonates between pleural-air interface and liver multiple times
with delayed signal transmission
b. US machine misinterprets the extra time as something further afield and thus plots more liver tissue
c. Mirror-image artifact present = no fluid in the chest
i.Ex. Very helpful in diagnosing hemothorax and pleural effusion
Ultrasound waves - Answer-a. B-mode (greyscale) imaging depicts internal tissue structure
