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
Slide
Move transducer to different areas of the abdomen without angling transducer
Fan
Move transducer perpendicular to scan the plane (side to side)
Rotate
Move 90 degrees to the starting plane
Best for cross-sectional views of structures
Hyperechoic
Brighter than normal (mass, ST)
Hypoechoic
Darker than normal
Isoechoic
2 structures of the same echogenicity
Anechoic
No internal echoes- very dark on image (fluid)
SLK
Spleen more hyperechoic than liver, liver more hyperechoic than renal cortex
Acoustic shadowing
Dark streak to mineralized/ dense tissue
Calculi, ribs
Reflective or refractive
Far field/ Distant enhancement
Hyperechoic area distant to anechoic structure
Bladder and cysts
Structures seen in a normal liver
Echogenic diaphragm
Heterogenous/ coarse in echotexture
Portal veins (echogenic borders)
Hepatic veins
Falciform fat
Cd. vena cava
Gallbladder
Structures seen in a normal spleen
Homogenus in echotexture
Echogenic capsule
Splenic vessels course into parenchyma
Heady, body and tail
Normal kidneys
Sagittal plane: football
Dorsal plane: lima bean
Transverse: cross section
Normal prostate gland
Heterogenous echotexture
@ neck of the UB
Urethra goes through the middle
Large in intact males
Normal uterus
Not normally visualized
Hypo during estrus and early pregnancy
Determines fetal viability
When is fetal cardiac activity detected on an U/S
28d