Ultrasound Flashcards
What is ultrasound?
High frequency sound waves bounce of organs and time taken to return is measured
What is the most common type of US?
B mode or 2D
What are the 2 probes used?
Curved array transducer =. Low frequency 3.5MHz
Linear probe = higher frequency 10MHZ so better resolution but cant see far into the body
What do we see when we use US on chest wall?
White line - lung wall
This slides back and forward in normal people = GLIDING PLEURA
What are A lines?
Run parallel to gliding of lung and are artefacts caused by sound moving back and forward in lung
What are B lines?
Perpendicular to lung wall
Every time interlobular septa hits lung wall = line
What does M mode US measure?
Movement of tissue over time
Normal lung looks like seas shore as straight lines for muscle until inside lung where there is movement so it looks like granules
What plane is the best way to look at lung?
Paracoronal and parasagital plane as ribs cannot be seen
What do we use US for?
Detecting pleural effusion
Assessment of respiratory muscle function
What does a pleura effusion look like?
Black fluid between lung wall and chest wall
US is more sensitive that x ray to see pleural effusion
What happens tho muscles during inspiration?
Diaphragm contracts
Scalene and contract and move sternum forward
External intercostal contract and elevate ribs
What innervate the diaphragm?
Phrenic nerves from C3,4,5
Damage = paralysis of diaphragm = so it moves up in the chest
What are other causes of elevated diaphragm?
Large liver pushing it
Subphrenic abscess
Trapped subpulmonary fluid
How do we test the phrenic nerve?
Sniff
If normal = fast movement to feet
If paralysed = movement to head
