Liver lecture for Quiz 1 Flashcards
What is the order of annotation?
Organ, scan plane, left/right (except Kid/OV), special notations
How should you feature the anatomy on U/S?
Center the anatomy or area of interest and zoom
In abdominal studies, what should rarely happen with the patient?
Supine as the only position
What are three ways to move the patient?
LLD/RLD, sitting, LPO/RPO
What 12 things do you consider with optimizing an image?
Presets, transducer selection, frequency (high/low, multi Hz, harmonics) depth, focus, gain (overall, TGC) sector size, zoom, compression/dynamic range, B-color colorization, post-processing, sweep/video clip
When selecting a transducer, what two things do you consider?
Axial resolution w/higher frequencies (smaller SPL, better front to back resolution), Depth for low frequencies
What do you consider with frequency selection?
Penetration and resolution needs, harmonics
What five things do you consider when dealing with depth?
Shallow vs. deep, two fingers from bottom, don’t cut anatomy off, don’t waste far field, if you change depth also adjust focus tool
What produces best reflection with B-scan?
90 degrees to the wall
What 5 things do you consider with lateral resolution?
Beam width, focus, better used with non-moving structures, enhancing image in a specific region, position at level or just below ROI
How do you optimize beam width?
Use focus (narrowest part of sound beam)
When should you use multi-focus?
It is better used with non-moving structures (use at the sake of temporal resolution which slows down the frame rate)
What 3 things occur with sector size?
Narrowing sector size will get rid of unnecessary information/improve overall resolution of the image, zoom, enlarges the ROI without loss of quality
What 3 things do you consider with dynamic range or compression?
DR (range of grays between smallest and largest signals), compressions (varying shades of gray due to compressed signals), contrast vs gray scale
What 2 things do you consider with B-color or image colorization?
Substitution of the basic grayscale image w/hue other than gray to improve visual perception of images, can be helpful w/doppler spectrum
What does the ligamentum teres also act as?
Collateral flow with portal hypertension
What is another term for ligamentum teres?
Round ligament
What conditions do we need to determine when scanning liver?
Hepatomagaly, splenomegaly, renal impairment and abdominal aortic aneurysm
Why does liver measurements need to be consistent?
To be able to compare sizes over time
What should be used ideally with positioning in a follow-up assessment?
The calipers need to be positioned in the same position and ideally the same sonographer used
Where does the upper border of liver lie?
Right midclavicular line at the 5th intercostal space
What do most people have in terms of the lower border of the liver?
It extends to the lower costal margin
Where do you measure liver?
The posterior diaphragm to the lower anterior edge
How does liver size increase over time?
Gender, age, height, weight and body surface area
