Intro to U/S Flashcards
Diagnostic U/S
Non-ionizing high frequency sound waves generated from a transducer
How do U/S work
Sound waves penetrate tissue → reflected from interfaces with different acoustical properties → sound waves return to the transducer as echos
What do abdominal U/S tell you?
IDs location of organs and structures
Internal architecture of organs
Lesions
Small amounts of effusion/ fluid in cavity
When do U/S detect pregnancy?
20d
Patient prep for an abdominal U/S
Fasting 12 hr before the exam
Shave from xyphoid along costal arch to pelvic inlet
Clean surface with alcohol + acoustic gel
Real time B mode
Abdominal U/S
Fluoroscopy of diagnostic U/S
B-mode or brightness mode
Imaging all areas of the body
M-mode/ motion mode
Used for echocardiography(measures wall thickness and contraction of the heart)
Narrow, stationary U/S
U/S transducers
Abdominal: small to large flat surface with curved edges
Cardiac: small flat/ pointed surface with curved edges
Extremities- flat surface
Sector (transducer shape)
True “pie, wedge or fan” -USE
Diverging scan field, phased array (cardiac), curved liner array (abdomen)
Linear array transducer (transducer shape)
Rectangular or trapezoid shape
Higher frequency is necessary for better resolution
Electronic array (probe type)
Use of an electric pulse through crystals in the probe to generate an image (quiet)
Preferred
Mechanical transducer (probe type)
Use of mechanical parts to generate an image (noisy)
U/S penetration
Higher frequency → superficial penetration → better resolution
Lower frequency → deeper penetration → decrease resolution
Roll
Transducer in same plane, pointed cranially or caudally
Used at costal arch and pelvic canal
